First Autocross

[GTBradley]

Well, I finally got around to enrolling in an autocross event, in fact, I did the Rocky Mountain Region's Porsche Club Autocross University this last Saturday and then their regular autocross event on Sunday. Let me say first, this was the best experience I've had in a car! well...ah...you know what I mean. The training was very helpful. They had us do skid pads, which are just big circles while holding the steering wheel steady and steering with the gas; slaloms; and triangles, where you speed from one gate straight to the next - brake hard, turn hard, go hard. Then, in the afternoon we practiced an autocross course. I learned a lot and and had blast!

Sunday was the real autocross with 70 or more attendees. I ran over a few cones and got a couple of DNFs by missing gates, but in the end I think I did okay and the car is fantastic! The issue I need help with is car handling, as in, the addition of anti-sway bars, and or...suggestions appreciated.

I'm pretty sure I need the front bar to control the oversteer I'm experiencing, but I don't know that I need rear bar, and if I do, I won't install it until I can do another autocross to see the result of adding the front one. I've got a very short video of my runs and input is appreciated. I can tell already that I need to tighten up against the cones more, but beyond that I really don't know what I'm doing wrong, or right. It's pretty much all instinct right now, other than some things I can apply from the training.


https://youtu.be/oW8PiKf5-iQ

Also, I see that Mike Forte has just the front anti-sway bar for $189. Is this a good one to install and where would I look for one for the rear?

Thanks

[J R Jones]

GTB, you appear to be on the right track. If you have no anti-roll bars add one to the front and evaluate. Then you may be able to add a rear bar but a rear bar can make oversteer worse. A locked differential will also make oversteer worse. Testing at different places or different days is confusing. If you add a front bar, make a run with one link disconnected. Connect the link and make another run. The difference will be apparent.

[GTBradley]

I didn't think of disconnecting the bar to evaluate, thanks, I'll do that.

What causes a locked differential, by the way?

[Jeff Kleiner]

Let’s start with the basics—what is your tire pressure? I’m not seeing steady state oversteer; I’m seeing a snap oversteer when you jump out of the throttle while it’s pushing. With the factory spring rates our cars understeer and adding a front bar without a corresponding change to the rear will exacerbate that pushing condition. These cars run on a knife edge and reward smooth. You have to go easy with the inputs; no jerking the wheel and no treating the throttle like an on/off switch. When I instruct novices they almost universally think they need to change the car but more often than not there are 3 other things that they need first 1) seat time 2) more seat time 3) still more seat time ;)

Jeff

[mike223]

When I instruct novices they almost universally think they need to change the car but more often than not there are 3 other things that they need first 1) seat time 2) more seat time 3) still more seat time ;)




It's going to take your average non-autocross experienced enthusiast at least two years (20+ autocrosses) to learn to manage one of these cars "pretty well" on an autocross course.

It would take a "good" fast experienced Miata driver at least a year (maybe more).

It's one of the most challenging cars you could pick to learn to autocross "well".


The tricky thing about them is all your driver inputs (can/should/will) cause a whole lot of weight transfer - real fast - with consequences.

Once you learn to manipulate that weight transfer to your advantage - it's a beautiful thing.

Until then - most chassis modifications are pointless.


On an autocross course - the driver's ability to transfer that much weight, that quickly - can make the best handling car completely unmanageable (with the wrong driver input), and a poor handling car FTD (with the right driver input).

There are few other vehicles that compare in that regard.


Looked like you got through your first autocross pretty well to me - no disasters - keep at it.

[Mike N]

As Jeff said, Smooth is fast. Smooth also feels slow. If you consciously ever so slightly slow down your throttle and brake application (weight transfer) you should find things easier to control. My first year at auto x the two biggest changes I made to the car was a seat with more lateral support and a Russ Thompson gas pedal that is far more progressive and less like a switch. If you mess with the car set up at the same time you are learning the car you will probably get frustrated. Get a good alignment and make sure your tire pressures are consistent. My car likes 21/22 front and 23/24 rear. Then practice learning the car. I had a local pro drive my car a couple of times with me as passenger. His first run he was 2 seconds faster than me having never driven the car. With him as passenger and a little instruction on unlearning bad habits I was soon much faster.

[Jeff Kleiner]

I wasn't going to go there yet with my earlier post but since Mike & Mike started talking transfer of weight I will---there is no better time than now for you to start learning left foot braking. This allows you to modulate the brake and throttle together to smooth those transitions. You'll be applying brake (sometimes a lot of it!) before you're fully off the throttle and vice-versa. It will allow you much, much more control on turn in as well as coming out than doing a busy and clumsy one footed dance with an on the gas...off the gas...on the brake...off the brake...on the gas routine. You can often feel the car start to move in an unwanted way and settle it with just a little more brake without having ever having to get out of the throttle---or the other way around.

Whatever you do though HAVE FUN!

Jeff

[CraigS]

I agree to some extent w/ the you need seat time comments. Still your car is loose. A couple of questions;
- what tires and what tire pressures?
- what alignment specs are you running? All of them please.
- what springs front an rear?
A way to get some idea of camber and tire pressures is get an old school white shoe polish w/ the sponge applicator. Put 3 inch or a little more dots at the edge of the tire tread. This will show you how much the edge of the tire is rolling over. You want the white worn away down to the tip of this triangle.
https://live.staticflickr.com/7842/40548232833_f633fc277d_z.jpg (https://flic.kr/p/24M7hWD)Tire triangle (https://flic.kr/p/24M7hWD) by craig stuard (https://www.flickr.com/photos/152454123@N04/), on Flickr

[TMartinLVNV]

Bradley, this is something that I also want to try. I'm pretty nervous to do it. The training beforehand is pretty awesome too.

When watching your video, this is what came to my mind ;)

https://hosting.photobucket.com/images/pp213/tmartinlvnv/spaceballs.jpg?width=960&height=720&fit=bounds (https://app.photobucket.com/u/tmartinlvnv/p/cca08f00-dd19-40af-bbfe-d97e5cf0b668)

[J R Jones]

GTB, As you can see there are suggestions beyond your anti-roll bar (ARB) question. Indeed acquired experience improves performance but also understanding of what the mechanical bits are doing. Do not underestimate yourself. Some people are naturals and develop driving skill quickly (Mark Donohue); some people just don't get it (my wife). Your SCCA event sounds like an excellent learning experience.
My locked differential comment is not malfunction related. Differentials can be open, limited slip clutch type and limited slip ratchet type. There are also "spools" that lock the axles together. As the axles are coupled together the outside (heavily loaded) tire dictates the axle/tire RPM. The inside tire (lightly loaded) on a smaller radius has to compensate by skidding. That can result in oversteer. In the seventies I set up a Shelby GT350 to run a Trans Am at Elkhart Lake. I had previously run a 289/302 with 3.89 gears on a Detroit Locker (ratchet type) differential. For this event I had a Boss 351 and was over-revving on the straights. I was out of Lockers and set-up a 3.50 gear set with a (cheap) spool. Next day the Shelby had transitioned to oversteer. We disconnected the rear anti-roll bar and the car improved dramatically. The reason? In roll, the inside ARB link is restaining the body lift and unloading the inside tire, leading to more skid.
Other things to consider is weight proportion and power application. A big block cast iron engine has weight bias forward, and a lighter rear axle. If you have adopted the huge power philosophy, that makes autocross more difficult. I was asked to run a GT40 MKIV (427 side oiler) at an Elkhart Lake vintage event. The car was hard to drive in traffic and passing was compromised by (2) 4V carburetors with all throttle plates liked together. Acceleration was explosive. Not only was oversteer an issue, I could not follow other cars closely to set-up a pass. A progressive throttle makes a car easier to drive.

[GTBradley]

Thanks for the input guys, except you, Terry, but I'll get to you later.

I understand seat time is king, I am a professional pilot and the value of chair flying is very important too. I'll keep at it.
- Tire pressures are 22 all the way around. The car weighs 2272 lbs - maybe I should go to 23 psi?
- The throttle is a problem, no doubt. It's the electronic control pedal for the Coyote and the engine responds so quickly that I know I'm causing a problem. The pedal had to be shortened and that just makes it that much more sensitive.
- What I'm getting is that the car doesn't necessarily need the ARBs (thanks for the initialism, JR...much easier!), front or rear. That was the reason I didn't add them during the build, but so many builders add both that I figured there was an obvious need for them. Not to mention, every experienced driver I talked to at the event told me to get the front one. Granted, they don't know these cars. I'll get better at this and then consider it.
- What the car does need is accurate, controlled inputs. First, I will try the right foot throttle and left foot brake technique. This will be a good time to set that habit for Autocross and is easy enough to do as I don't need to shift out of first anyway - not impossible I know, but just less to do for this novice. Second, I bought a heel stop from Breeze and will install that to give me, hopefully, more stability, reference and control on this hyper-sensitive gas pedal I have. Third, I'll slow down the inputs. That's a tough one because I'm very excited and happy driving the course. Discipline! Smooth weight transfer!

The springs are standard FFR kit springs - front: 500#, back 400#. I'm wondering about the fronts now though, the engine is only 445 pounds, but I have the battery up there too. My corner weights resulted in nearly 50/50 weight distribution front to back with just a bit of rear bias. The shocks are the Koni red single adjustable and the ride height is 4.5 inches front and back. The white dot is a nice idea Craig, I'll try that.

JR, I'm almost sorry I asked about the diff lock:o. I'll save that education for when my brain is bigger.

Alignment specs:

147012

And last but least, Terry, I was way deep in this treasure trove of technical information so graciously given by these talented people that when I looked at the picture you posted my first though was: hmm...those people are looking at a monitor...ah! my video is what they are looking at and their faces seem to show they are impressed by my driving?...wait...no...there is a white bubble helmet!...yep that's me. I snort-laughed at that one. Thanks, buddy.

[J R Jones]

GTB, I am new to this group and by nature, I do not pay attention to embellishments. If I had reviewed your signature(??) I would have seen two details I questioned, rear axle type and engine.
Your comment on (not) shifting causes me pause. I have difficulty hard-driving a car in first gear. Not only does it slap-load the driveline to excess, the weight transfers are huge. Additionally it results in an excess of rear wheel braking on decell. Adding hard braking to 1st gear decell can cause the rear tires to lose traction. I suggest using second gear regardless of not being at optimum power and torque. You have plenty of power and minimal weight. The throttle inputs will be more modulated and decell brake from the rear tires reduced. I assume you do not have an automatic transmission.
I was USAF with Fighter/Interceptors and respect the capability of pilots. I predict that you are a "natural". Back in the day the Road Atlanta road course was purchased by the Porsche endurance racing Whittington Bros. They were consistent winners "out of the box". Road and Track magazine interviewed the Whittingtons and asked "Where the hell did you guys come from?" Answer: "We have been pylon racing aircraft for years, this car racing stuff is child's play". I attend the Reno races, and I get it. OTOH there was the issue of their substantial wealth, which turned out to be large scale drug commerce. They were not nearly as fast in jail.
BTW you may consider going to a cable driven throttle body that can be set-up to your preference.

[Jeff Kleiner]

I didn't catch that you ran the entire course in 1st gear when I watched the video but I agree with J R.; that's a big contributor to the extra sensitive throttle. I'd grab second between the first and second gate and stay there. Your tire pressure is a good starting point (I think you're running 555G2s right?) You could come down a bit but I wouldn't recommend going up because that will begin to lessen your contact patch. I usually run very low 20s and high teens on R-Comps depending on the temperature and surface, often times with a 1-2 psi front/rear split.

Jeff

PS to J R Jones: If you didn't happen to catch the news, Bill Whittington died when a plane he was piloting crashed in Arizona last Friday.

[GTBradley]

Embellishments!? No one has any embellishments in this forum! You are correct, it’s a five speed manual. I was so impressed by the engine’s wide rpm band it never occurred to me that the back-pressure alone would cause rear braking issues. Point taken, straighten up and fly right it is! I don’t know about “natural” but I do have the confidence to push my comfort level and that can help.

In my corporate flying days I had a couple of guys pursue me for a while to fly for them. They were fond of telling everyone how rich they were. I dodged them until they went to federal prison for campaign finance law violations and wire fraud.

Welcome to the forums, you’re an asset to us already.

Correct, Jeff, they are the triple fives. I’d read, probably from you, that starting on less sticky tires will help me learn. I’ll keep it to low 20s psi range.

[Mike N]

Before you consider a cable throttle it's worth noting that with a drive by wire throttle sensitivity is adjustable with a simple tune and customizable to almost any progression you want.

[GTBradley]

Before you consider a cable throttle it's worth noting that with a drive by wire throttle sensitivity is adjustable with a simple tune and customizable to almost any progression you want.
That’s good to know, thanks. I’m guessing that second gear is going to have a pretty pronounced affect on the “switch” like condition you mentioned, so I’m hoping to not have to spend that kind of money just for throttle application. We’ll see - I’m enrolling in the very next autocross event in May.

[Avalanche325]

If you had fun and got at least one timed run in. Good job on your first autocross! You did a nice job catching the car when it got loose.

I get out of 1st immediately. Launch (you can launch a little harder in my opinion) and short shift to 2nd. These cars a bucking broncos in 1st. What gears are you running? That was a pretty open course and I didn't hear any rev limiter.

Mark your sidewalls with sidewalk chalk ... it comes off easily. Adjust your tire pressure according to that and the triangles mentioned above.

For sway bars. Yes they definitely help these cars, and you could go ahead and do it. However, there is no need to do ANYTHING besides adjust air pressure for the first season. For the first two seasons........it ain't the car ;-) I am running VPM swaybars on a 3-link. Front is set to stiffest and I adjust with the rear.

When you do start spending money, start with tires. 555s are a good cruising tire. NT05s are a good all around tire. Tires are what make you accelerate, turn and stop. They are the single best upgrade. I also agree that less grippy tires are good for the 1st season learning curve. Well, maybe your own helmet 1st if that was a club loaner. Loaners get real nice in the summer.

Get a camera mount that will let you see what your hands are doing. Looking at the back of your helmet really doesn't help to see what you are doing.

I find that if the car is 100% hooked up, I am slow. Mine has to be dancing on the very edge. Try to never coast. You should be accelerating all the way to where you have to brake.

I haven't been for a while due to COVID, I am getting back out in a few weeks.

[GoDadGo]

Go-Dad's Input:
You Drive Better Than I Do!
Looked Like An Absolute Blast!

[GTBradley]

Thanks and, yeah, I felt like I was progressing and learning. In the morning two runs were DNF, then one cone, then a good run. In the afternoon two DNFs and then two good runs. My best time was the 7th run and it also had the most "dancing on the edge" ie. the video. That put me about two thirds the way down the list of times at the end of the day.

The gears are 3.55. I did see I recorded a top speed of 47 mph and that would put me at about 6200 rpm with a 7000 redline. The Space Balls helmet is mine - I really didn't want to stick my head in an old, sweaty helmet countless other people have worn.

Good luck getting back out there.

[J R Jones]

GTB, There are cars designed without ARBs and they do OK. Spring load limits are experienced under max braking (2) and max cornering (1). Bottoming in either case results in no suspension travel, leaving the spring rate of the tires to adsorb surface deviation. Tire hop can result. Installing an ARB adds to roll spring rate. An ARB could be combined with lighter coil springs for more suspension compliance. We ran a season of SCCA Showroom Stock "B" against Saab 900s and they had outrageous roll angles, and won the National Championship. Racing in the rain, roll compliance and (side) weight transfer is advantageous for traction. ARBs are disconnected.
An advantage you have as a pilot is operating in three dimensions, you have to see more and react more. Obviously even in IFR your senses are acute for survival. The horizon is a constant reference. Your reference on the track is similar in that you should not be monitoring the environment around the car. You should have the next cone memorized as you seek the cone(s) further down the course. Muscle memory is in the corner, your head is down-range.
In the back of my mind I seek energy conservation. The corner will adsorb some forward momentum, and the brakes supplement as necessary to make the turn. Obviously long straights require braking to set-up the turn. Eventually you will be picking apexes, a more specific conversation

[GTBradley]

And here I was thinking of buying a book on the subject. It really seems that you know this sport! Maybe you should write a book. Thanks for all the advice/education. I can see this becoming a serious pastime for me and this help early on just adds to the excitement.

I really didn’t have much trouble looking past the next cone or two once I told myself to do it, but I haven’t developed the spatial sense that would allow me to get tighter to the cones. In fact, I was impressed with my ability to avoid hitting them until I saw in my video how far I was from them. The big thing for me will be developing that “line” in my head. Gotta stay ahead of airplane, right?

keep it coming, I’m sure many other people are enjoying this too.

Bradley.

[J R Jones]

Brad, Autocross attracts a variety of cars which makes for entertaining competition. Each contestant has strengths and weaknesses. Playing on strengths means not all cars will address the course in the same manner.
You would not look to a Mini Cooper or Lotus for technique. A WWII P-38 pilot told me of dogfighting Mitsubishi Zeros over China. The Nippon Ace got on his tail and Ralph used the "energy tactic" for escape. Full Mill from two 2000hp Allisons spinning 12 foot props provided a vertical climb to safety.
Prior to running for effect, evaluate the course for your energy tactics. The best line through the corners is not necessarily the tightest radius. Some corners are just a means to optimize the straights for maximum speed.
For instance picking an early apex before a straight means you dwell through the turn before acceleration. Coming in from the outside and a late apex positions the car to accelerate straighter and earlier. On the other end of the straight, provided the turn does not lead to another significant straight, you may consider late braking over optimum corner speed.
BTW I was at Lowry AFB 12 months for training and had a part time job working near Cherry Creek for Vince Martino. Vince had full service Texaco stations and a tire store. Quite a guy.

[Avalanche325]

You will find that most of your cone strikes will be with the rear of the car. As JRJ is saying, late apex is your friend. In autocross terms, "back-siding the cone".

On the course walk. Walk where you (not the center of your car) will be. You should be right next to the cones on the left and 4 ft away from the cones on your right.
Find the fastest section or two. Then do everything you can to come out the preceding element as quickly as possible. Even if it means going in extra slow.
Find the slowest section. Then realize it is going to be slow no matter what. Don't try to make it fast. Just keep it tidy. You can lose a lot of time trying to take a 20mph turn at 21 mph..
Almost always, the shorter distance is faster than carrying speed in autocross. Unlike a road coarse.
A little bit of slip angle. Never drift.........well if you want a fast time. It sure is fun though.

You should be looking very very far down course. Way more than a couple cones. I went to an SCCA Starting Line autocross school run by two national champions. They had us walking the course. One of the instructors walked crazy far down course and then they said , "That is where you should be looking". I thought I WAS looking down course. But needed to double it. I was also looking at apex cone on a turnaround, and have since learned to look at the exit cone as I am entering.

Here is a little warm up that I do on the way to the event, if you have open road. I move over until I am just clipping the lane reflectors on one side then the other a few times. As I am moving over I try to nail exactly when I will start hitting them. That helps with refreshing my memory on where the outer edges of my car are.

[Jeff Kleiner]

A 40 year autocrosser once told me that anyone who never hits a cone thinks his car is wider than it really is! An exercise that we sometimes do during our novice schools us to send drivers out and tell them to clip some cones to help them learn where the corners of their cars are. Oh, and our cars WILL blow cones over with the exhaust if you’re close to it and hard on the throttle. I’ve been told more than once by courseworkers that they’ve seen it happen.

Jeff

[GTBradley]

Finally came up with a negative aspect off side pipes.

That's not a bad idea, I think I'll purposely try touching cones on my first runs, I was running them slower anyway.

[nucjd19]

I just wanted to chime in and say thank you to everyone that have been posting. This has been an excellent and informational thread. I can't wait to get my rig out there soon and give it a go in my roadster and some schooling as well.

[Jeff Kleiner]

My friend Ben caught me in an "Eyes up and looking ahead" moment a few years ago...

https://thefactoryfiveforum.com/attachment.php?attachmentid=147075&d=1619656005

Our minds have an amazing ability to take in what's ahead and process it long before you get to it while still unconsciously maneuvering us through the previously processed part of the course we're on at that instant. Keep this in mind:The hands go where the eyes go This plays right into something that I tell the students when instructing---"If you're not focused ahead and are looking directly at the cone you're approaching you'll hit it!"

Cheers,
Jeff

[CraigS]

Yes, 2nd gear will be a much smoother run for you. A few times per year I get a course where there is one very slow turn and am tempted to go back to first. I have tried it a few times and it never works out. Too much power at first and then wasted time going back to 2nd. Looking ahead is key. The next turn almost allways determines how I will do this turn. Last weekend we had a part of a course where we had a series of 2 cone gates forming slightly curved straight and then a slalom. They were both going the same direction but the slalom was offset to the right by maybe 100ft. The first cone of the slalom was 200 ft past the last gate. The tendency was to hold the gas down as long as possible after the last gate and then make the jog over to the slalom. I was lucky enough to see that part of the course while I worked. It was immediately obvious that one needed to slow going through the last gate, actually starting the turn to jog over to the slalom a little before the last gate. That meant I was as far left as possible through the next to last gate, right on the right cone and already turning at the last gate. If that slalom had not been there I definitely would have been going through those last 2 gates differently. One other tip I have found useful is figure a way in your mind to describe the overall course. Helps me not get lost. For instance on a rectangular lot, if looking at it from a drone, it might be in landscape orientation and start is at the left lower corner heading up along the left side. A way to describe the overall shape might be this; it is a huge extra wide letter 'M' with the points rounded off, the first point of the 'M' is a big wide 180 deg turn, the center point of the 'M' is actually more of a square, finish is a slalom coming down the right leg of the 'M'.

[GTBradley]

That is a nearly identical instruction I gave my flight students, Jeff. They tend to stare at the point they want to land and end up hitting hard sooner. Looking farther down the runway gives a much broader picture of what is happening all around.

Nice action shot there, by the way.

[GTBradley]

Craig, that sounds a little like the setup for the slalom I was doing. I wasn’t sure weather to treat it like the triangle exercise - head straight at it brake hard and turn hard - or sweep wide to be in position for the slalom entrance, or just not accelerate and keep it slower. Sometimes it seems really difficult to see what is best.

PS. I bet that hardtop comes in handy when waiting your turn at the start line in July.

PSS. Did you get a chance to look at my alignment specs?

[Rdone585]

I'm sure Craig will take a look soon. As pointed out earlier, an abundance of seat time before making too many changes will be the best thing for you in the long run. Hear are my thoughts on your alignment specs, you could benefit from running more camber in the front. My front camber is -1.8 degrees. I have a solid axel rear, so that's not adjustable for me. I've been told that rear alignment can make dramatic improvements in car performance. If you have a IRS, there may be some benefit from putting more camber in the rear also. Others can provide better advise about rear setup with IRS. Running more camber (front or rear) can cause quicker wear on the inside of the tire. If you also do a lot of street driving, you may notice this sooner, so manage accordingly. Some drivers with the ability to do their own alignments may have different setups for street versus track use.

[J R Jones]

GTB, Opinions on alignment specs is a bit like debating politics. Diverse opinions!? My career has been development at and for OEMs and I understand how much time and money they spend on that. I will weigh-in but defer to your assembly manual, the FFR Tech Department and Jim Schenk. Your car is straight forward without the influence of FWD or AWD. My guide is Carroll Smith's Prepare to Win, despite it's origin in the seventies.

The castor is excessive, for the street but more so for autocross. 7+ degrees leads to high steering effort and hard self-centering. 2.5 to 4.5 will steer quicker and still be straight line stable.
The camber is OK but you might measure camber gain with suspension deflection (like bump steer) Increasing camber with jounce to -2.5 degrees is good. After a run if you measure excess heat on the inside tread, your camber may be too negative.
Toe in front is OK, could be half that as long as straight stability does not degrade.
Toe in rear is to compensate for suspension deflection under acceleration/braking. 0.12 is a little high, especially if you do not have plastic/rubber bushings.
I am surprised at the wheelbase difference. It is a challenge to alter that with (rear) adjustments and maintain alignment. Maybe half on one side and half on the other.
Craig and I have discussed bump steer. It could be helpful, but more for the street. Many like the dial indicator method, Craig and I prefer a laser.
With spring/shock, wheel/tire removed:
Place a laser (line or gun-sight dot) on the wheel hub aimed to the side. Place a target field at the tire tread radius distance. Trace the laser at ride height.
Cycle the suspension to jounce and droop to see if the laser moves off the tracing. The difference is bump steer.
jim

[Matt Ries]

I'm always amazed by by the Factory five community willingness to share there wealth of knowledge! GTBradley, I think I might be this summer 4yrs of playing this Autocross game, it really is a lot of fun! I still think of my self as a rookie :) I think of it like a theory that you have to prove out, examine, inspect, question, make notes, make changes and repeat. Make notes is what I would add this this thread, I keep a little black note book to log as much as I can. I can't remember numbers, and there are lots of them in this game, Temps for example; 4 tires, 3 each, temp for the day, morning, noon, evening? engine temp. Tire pressures. Heat cycles. Dates, suspension alignment settings, shock settings. Corner weights, fuel load. Plus changing the loose nut behind the wheel (Me). Start basic tire pressures and temps add as you go and as you feel comfortable. This thread has a lot of information in it I want to take a highlighter to it and keep in my book!

[mike223]

Playing on strengths means not all cars will address the course in the same manner.
You would not look to a Mini Cooper or Lotus for technique.

The "perfect" Miata / Mini Cooper line is certainly not always (or maybe even often) the same line as would be for these cars.


But I'm occasionally reminded that (in autocross) I often have to run the same line they're running because their (high) traffic is keeping their line clean and throwing all the debris (pebbles, scruff, etc) on to my (higher power / lower traffic) line.

And the cleaner line is simply faster than the ideal line.


Not to disagree - just food for thought - an observation.

[CraigS]

I think your specs are fine for the street. I run a LOT more camber because I prioritize AX, -3 front and -2 rear. I use cheap as possible street tires so I just put up w/ them wearing off the inside edge. They still last 4 years or so. I checked your build thread and see you have power steering so the 7 deg caster is exactly what I run. You may end up wanting to be able to do your own alignments. Just depends how serious you want to be about AX. If you do decide on that we can help w/ equipment thoughts. You can get everything you need for <$300 so that compares pretty well vs paying someone to do them. But for now, lets see how you do running 2nd gear. I think you will have much less oversteer so it will be a lot easier to drive. When you are judging your handling balance keep a couple things in mind;
- slaloms are generally faster w/ a little more understeer(BTW when you walk the course measure the distance between cones by counting steps of any slaloms w/ 4 or more cones. It doesn't matter the number, you just want to know if the spacing is the same all the way though)
- if you have a nice wide turn of about 180deg this is where you can judge pure mid turn balance and it's nice to have it perfect to a tiny bit loose
- balance can vary on different parts of the course due to surface type and amount of debris/sand. So, if you are always loose in a given turn, ask a couple of the guys near you in the grid how it is for them. Just be sure they are driving a rear drive car. If they are loose too, then you just have to drive around the problem.
- don't make any changes based on the first run. Wait until after the second run to make notes and/or change something.
- I always drive every run as fast as possible. I see/hear some say they do the first run slightly slow to learn the course. I don't think I have enough runs to plan on throwing one away. I feel they 'may' learn the course but they don't learn anything about how the car is doing by driving at 90%.
- we all love the sound at full throttle so the tendency is to try to hold it as long as possible. But understeer is often not the car, it's the driver charging into a turn too hard. I would much rather be 2 mph slow on entry but be able to get back on the gas sooner.

[BradCraig]

I think your specs are fine for the street. I run a LOT more camber because I prioritize AX, -3 front and -2 rear. I use cheap as possible street tires so I just put up w/ them wearing off the inside edge. They still last 4 years or so. I checked your build thread and see you have power steering so the 7 deg caster is exactly what I run. You may end up wanting to be able to do your own alignments. Just depends how serious you want to be about AX. If you do decide on that we can help w/ equipment thoughts. You can get everything you need for <$300 so that compares pretty well vs paying someone to do them. But for now, lets see how you do running 2nd gear. I think you will have much less oversteer so it will be a lot easier to drive. When you are judging your handling balance keep a couple things in mind;
- slaloms are generally faster w/ a little more understeer(BTW when you walk the course measure the distance between cones by counting steps of any slaloms w/ 4 or more cones. It doesn't matter the number, you just want to know if the spacing is the same all the way though)
- if you have a nice wide turn of about 180deg this is where you can judge pure mid turn balance and it's nice to have it perfect to a tiny bit loose
- balance can vary on different parts of the course due to surface type and amount of debris/sand. So, if you are always loose in a given turn, ask a couple of the guys near you in the grid how it is for them. Just be sure they are driving a rear drive car. If they are loose too, then you just have to drive around the problem.
- don't make any changes based on the first run. Wait until after the second run to make notes and/or change something.
- I always drive every run as fast as possible. I see/hear some say they do the first run slightly slow to learn the course. I don't think I have enough runs to plan on throwing one away. I feel they 'may' learn the course but they don't learn anything about how the car is doing by driving at 90%.
- we all love the sound at full throttle so the tendency is to try to hold it as long as possible. But understeer is often not the car, it's the driver charging into a turn too hard. I would much rather be 2 mph slow on entry but be able to get back on the gas sooner.

Please let us know that alignment equipment list! My shopping cart was ~$700 so I welcome an alternative to do my own for a cheaper price point. TIA

[J R Jones]

CraigS, GTB, I do not know what is the traction benefit of more vs less caster. It does provide more steering feel, and return to center, so perhaps with power steering there is an advantage. A collateral result is that caster increases camber when steering, more more castor = more steer-camber. Many suspensions designs incorporate camber gain with jounce, so static camber + +?
Our last SCCA National effort was a Mitsubishi EVO in T2, with the primary competition Turbo Solstice (factory supported) and BMW M cars (factory supported). We got invitations to the runoffs all three years and was the highest finishing EVO. We ran DOT tires, mostly Hoosiers but got supported BFGs for a while. Tires were significant, requiring a break in process and they lasted practice-qualifying-race. Maybe one more practice session.
Common practice was measuring tread temperature after every session with the objective of even temperature (tire factory recommendation). If we ran uneven temperature the tread blistered and we lost.
As a side, our car chassis dynoed at 260 as new. With stock parts we pushed the 2 liter with 21lb boost to 360 on race gas. Our advantage was not AWD, it was power and brakes. We aligned the car for speed in the straights, no toe-in.
Some academic questions are:
Does the tread have more traction hot? Methinks yes. If the tread is hot on the inside and cooler in the middle and outside, is the net effect more or less total traction? Maybe there is not enough time to heat the whole tire. (skinnier tires?)
What is the traction result of PSI (pounds per square inch) If the tread is heavy loaded PSI on the inside and light PSI on the outside, is the net effect more or less total traction? Does only a portion of the tread grip?
A skid pad G-force evaluation (scientific method, ABA) of camber extreems would resolve this. I wonder if Jim Schenk has done it?
Understeer or "push" tells you when the front tires are losing traction. I have trouble seeing that as beneficial. Obviously oversteer is a disadvantage too, especially snap oversteer and recovery oversteer. Sliding has been critiqued earlier in this thread, there just is not enough room on an autocross course. My theory is that driving to the threshold of traction of four tires is better than the traction threshold of two tires.
I raced a Sunbeam Tiger that was wonderful in that regard. Lap record and wins.
jim

[Jeff Kleiner]

Jim,
In the case of our FFR roadsters and Coupes more positive caster is beneficial leading to straight line stability, return to center and camber gain when turning however as you've alluded to it becomes unmanageable without power steering. They are unique animals and power steering is virtually mandatory if you want to autocross one of our roadsters fast. My buddy Joe suffered through a couple of seasons with a manual rack before changing to power and making a corresponding alignment change to more positive caster. The result was an immediate 3 second reduction over a slalom heavy 50 second course. As for front toe; toe out will get a little more bite at initial turn in but with our cars can make them a little darty at highway speed. Personally I'm willing to trade that off for better highway manners and run mine with about 1/8" toe in. That bit of toe in wearing the outside of the tires kind of evens the inside wear caused by the 1.5 to 2 degrees of negative camber...in the end neither are consequential since the 100 treadwear tires I use are used up in <5,000 miles anyway. If someone was so inclined it would be quick and easy to give a tie rod end a couple of twists at the venue to change from a street friendly toe in setting to a more track oriented toe out condition---I'm just not that ambitious ;)

Jeff

[J R Jones]

Jeff, I understand. Looks like your alignment specs are more familiar to me. I agree with your sticky tire philosophy.
My last autocross experience was actually a BMW promotion, sent to me as a BMW owner and car magazine subscriber. They set-up a fair-park parking lot with a wet straightaway, and a dry AX course. They had a Volvo, Mercedes, Acura and the BMW 5-series. I expected the BMW would be quicker. A Pro gave us an in-car demo then we took turns. The Volvo was a yawn, the Merc was better and the Acura was spirited for a couple of turns, then the power steering pump ran out of pressure. I finished with shear muscle. The BMW was marvelous and I was flying on the pre-ultimate straight into the last hard left, then a short chute to finish. I late-braked wide with all I had and the Beemer was totally hooked-up. Crap! I underestimated the car and let-up on the brake to enter the turn harder. Wrong. The weight transfer and ABS had the front tires hooked up but when I lightened the brake the Beemer understeered through the cones. I wonder how the Backdraft with BMW suspension bits compares?

[Jeff Kleiner]

...I wonder how the Backdraft with BMW suspension bits compares?

Backdrafts are good cars! My Backdraft autocross buddy and I have swapped cars at events and have come to the same conclusion; his car with a Coyote has more power than my mildly built 325-350ish HP EFI 5.0 Windsor but mine has more grip. When we compete against each other it's a darn near even back and forth; sometimes he's faster and some times I am. Different ways of getting to the same end :)

Jeff

[Railroad]

Backdrafts are good cars! My Backdraft autocross buddy and I have swapped cars at events and have come to the same conclusion; his car with a Coyote has more power than my mildly built 325-350ish HP EFI 5.0 Windsor but mine has more grip. When we compete against each other it's a darn near even back and forth; sometimes he's faster and some times I am. Different ways of getting to the same end :)

Jeff

Jeff,
Do you know what rear gears your Coyote buddy is running?

[GTBradley]

Seriously guys, you know how valuable this information is to people looking to do autocross? I’m just trying to stay out of the way so the information can by laid down for posterity.

JR, I’ll be hanging on to this information for when I get my own alignment tools - next up will be a four post lift. Thanks too for relating the real-world experience and stories, they are valuable for context and entertaining.

Jeff, yes thats Exactly why I elected to install PS. I had ASBs on my order with FFR but swapped it at the last minute for the power steering rack after a conversation with Paul (EdwardB) about steering geometry.

I did count my steps on the slaloms and they were equally spaced, this time. However, while working the course the guys next to me, resetting the slalom cones put them back on some X’d out chalk boxes. That made for some confused and frustrated drivers for a little bit.

CraigS, thanks for any help you can offer on alignment equipment setup. I took my roadster to a speed shop this last time and they tried to hit me with $240 for an alignment, but came down to $180 after my jaw hit the floor. Definitely worth the investment in equipment and knowledge if I want to go back and fourth from street to track alignment settings.

[CraigS]

Alignment tools;
Caster/camber; for a long long time I just had one. Last year I bought a second one so things can move a little more quickly.
https://www.longacreracing.com/products.aspx?itemid=1798&prodid=7219&pagetitle=Caster-%2f-Camber-Gauge-%26-case-only---NO-ADAPTER
It has a 1/4 or 5/16 threaded hole in the end so this is my adapter made from a piece of shelving from HD. I got a piece of threaded rod, locktited it into the gauge, and use a couple of hard plastic washers and a Nylock. You need to be able to twist the gauge on the stud to level it at each 20 deg turn so the plastic washers allow it to be tight to the board but still rotate.
https://live.staticflickr.com/1755/42572430562_42b43fcc4b.jpg (https://flic.kr/p/27RYQpu)Align tool (https://flic.kr/p/27RYQpu) by craig stuard (https://www.flickr.com/photos/152454123@N04/), on Flickr
When doing caster you need to turn the wheels 15 or 20 degrees, set the bubble and turn them the same angle to the other side. The outer ends of the gauge are machined to this angle. To make it easier to see when you have the turn correct I velcro these to the gauge and eyeball so they are parallel to the side pipes.
https://live.staticflickr.com/1744/42623267491_6a10ef6046_z.jpg (https://flic.kr/p/27Wtosg)20180606_134740 (https://flic.kr/p/27Wtosg) by craig stuard (https://www.flickr.com/photos/152454123@N04/), on Flickr
Toein; I have for years been using a self welded up version of this.
https://www.longacreracing.com/products.aspx?itemid=2445&prodid=7212&pagetitle=Toe-Bar
but a couple months ago I got these.
https://www.longacreracing.com/products.aspx?itemid=2445&prodid=10270&pagetitle=Toe-Plates-with-Magnets-(pair)
They both give the same result but the plates are a lot less$. With IRS you need to get the toe correct but also need it centered on the car. IE you could have the toe correct but both wheels are pointed off to one side. I use a laser and a self made scale for this. This I lay down, slide under the car just behind the front wheel, stand it up and pull til the pvc hits the inside of the main 4 inch frame tube.
https://live.staticflickr.com/871/41458729111_5b428592af_z.jpg (https://flic.kr/p/26ayPLk)IMG_20170419_160800746 (https://flic.kr/p/26ayPLk) by craig stuard (https://www.flickr.com/photos/152454123@N04/), on Flickr
https://live.staticflickr.com/1750/42669853081_ed36d72996_z.jpg (https://flic.kr/p/281A9J6)IMG_20170419_160647869 (https://flic.kr/p/281A9J6) by craig stuard (https://www.flickr.com/photos/152454123@N04/), on Flickr
For many years I had just one caster/camber gauge, one laser, one scale. Last winter I decided to upgrade some so I bought another gauge and laser, and built another scale. This is the current setup.
https://live.staticflickr.com/65535/51151112744_d88a86f2f8_z.jpg (https://flic.kr/p/2kW3PJY)20210501_093241 (https://flic.kr/p/2kW3PJY) by craig stuard (https://www.flickr.com/photos/152454123@N04/), on Flickr
The laser has a magnet in it so I got a small piece of steel sheet and screwed it to the board. It is a very nice piece from HD but it's $60. Harbor Freight has one for $25. For anyone reading through this understand that doing alignments is not that difficult. But it does take time. Starting from scratch on a newly assembled FFR you can easily spend 4-6 hours. So the key is make the time work into your life and it can be very rewarding. But what happens w/ most of the specs is you have the reading, jack up the car, make an adjustment a guessed amount, drop the car, roll it and bounce it, and take a new reading. Hopefully each time you get closer to the desired spec but I manage to turn something the wrong way at least once every alignment. When you have spent an hour adjusting caster and camber and are still a 1/4 to 1/2 deg off side to side, if you are worrying about time that 1/4 deg difference may look to be good enough. If it's caster, it probably is good enough. If it's camber, it is not.

[J R Jones]

Craig, This pangs of scientific! Kudos.
I have built resto-rod chassis from scratch and from wrecks. I adopted lasers and digital angle gages to get dimensions correct and chassis square. By default I started with what I had on hand, and a gun sight laser still is valuable, I find the dot resolution is finer than construction lasers. OTOH the construction laser can provide a reference plane under the chassis. If I align one end suspension mounts to the laser plane, I can measure for twist on the other end suspension mounts. I was surprised to find error in a professionally straightened chassis. This lead to my measuring alignment, but I accept that my alignment is "ball park" and defer to professional machines.
BTW my measuring "kit" also includes four plumb bobs. Gravity is my friend.

When we raced the EVO we did measure and adjust at the track, including weight distribution at all four corners.
We used a stack of floor tiles to level the car at static ride height. The tiles were stacked under each tire and leveled by spirit or digital laser. The tiles had some lubricity to allow steering and the tires to displace laterally as the suspension settled. We also used a string alignment system which was fore and aft frames attached to the car, extending to the side at a level with the wheel centers. A string wrapped around the car on the frames and provided a reference to set toe, front and rear. Of course the vehicle centerline had to be identified.

jim

[CraigS]

I like the string on dedicated frames technique. I have seen a couple that used electrical conduit attached to the quickjacks. Strings attached to jack stands suck.

[Rsnake]

My method for measuring caster is using a digital level between the upper and lower ball. I have a price of metal machined to fit between the ball joint studs and the level fits on the flat edge. Always within a tenth of a degree from what a hunter alignment machine reads. Easy and works.

[Jim1855]

A slight diversion.

Are there differences between alignment specs for AutoX and Road tracks?

From my limited experience with other chassis/suspension designs I might think that there's a bit of toe-out to toe-in change but otherwise not much.

I really appreciate this discussion. Thanks to all for sharing your knowledge and experience.

Jim

[PNWTim]

My method for measuring caster is using a digital level between the upper and lower ball. I have a price of metal machined to fit between the ball joint studs and the level fits on the flat edge. Always within a tenth of a degree from what a hunter alignment machine reads. Easy and works.

Do you happen to have a picture of this?

[J R Jones]

Jim1855, As you can see in this thread, there are differences and in the case of AX there is a possibility of compromise for street performance.
There is also the influence of vehicle type and driver preference.
As sagely stated "The successful racing car is the best combination of compromises".

The stakes for track racing justify tuning at a higher level. For instance a road course within an oval like Daytona will demand weight jacking for the high bank.
LaCarrera Pan America will justify more robust parts, increased static height and lighter operating loads.
In either case the car can be tuned for maximum speed on the straight, but a second gear course is quite different from 165 to 185MPH. If nothing else the aerodynamic downforce and stability will influence set-up.
jim

[Jim1855]

Jim
Thank you. I've found that 140 is sufficient on the main straight at VIR South Track and Grattan.
I'm learning but have a long ways to go.
Jim

[J R Jones]

Racing a Shelby GT350 and Boss 302 in SCCA we had four differentials set-up for top speed at 7000RPM. The extremes were Blackhawk Farms, 4.56 and 110MPH to Brainerd or Elkhart 3.89 and 145MPH or 3.50 and 164MPH (289 vs 351)
The unlimited Studebaker 1953 Lowey coupes ran 185MPH across the LCPA Mexico desert.
I have seen Forum videos of 818Rs at VIR running the 2 minute challenge at what looked like 160MPH.
https://thefactoryfiveforum.com/content.php?697-Four-Factory-Fives-Rock-UTCC!-Two-Under-2-00!
jim

[JB in NOVA]

This thread is amazing! Please keep it going.

[AdamIsAdam]

This thread has some great info.

[CraigS]

I have run 4 seasons of SCCA regionals but it was a long time ago and in way different cars so my thoughts are definitely not definitive. I 'think' the main difference between AX and road course settings might be toe in or out. Sometimes for AX, people run zero or slight toe out in the front for quicker response at corner turn in. They may also run closer to zero in the rear. There is only so much trouble one can get into at 60mph in a parking lot, so going toward instability to get quicker response is not very dangerous. There might be some difference in shock and/or spring rates and their effect on acceleration squat. 3000rpm in 2nd (AX) gives harder accel than 3000rpm in 3rd and higher gears(road course). So an AX setup might have a bit more rear spring or shock rate which would also move the overall balance toward oversteer which is generally good for AX.

[CraigS]

I tried that a long time ago and couldn't make it work repeatably. My problem was that I couldn't figure a way to hold my little jig in line w/ the car if looking at it from the top. With both caster and SAI angles working at it, the slightest jig rotation changed the reading a bunch. BTW there is a formula where you turn the wheel 15-20 deg and measure camber. Then turn it 15-20 deg the other way and measure camber again. Plug in the two #s and out comes caster. Found it.

This equation allows you to use any angle so if you can't turn 20 degrees each way because the bar hits something, you can use 15 degrees or other.

Caster (deg) = (180 / 3.1415) * [(camber1 - camber2) / (turnangle1 - turnangle2)]

turn angle 20 degrees each way = 1.43 x camber diff (commonly rounded up to 1.5)

turn angle 15 degrees each way = 1.91 x camber diff (commonly rounded up to 2.0)

[J R Jones]

Jim1855, There are differences beyond alignment as you would expect, and they used to be fewer and simpler. Think power.
In the sixties/seventies the Pro cars (Formula and Sport Racer) were sophisticated and driving required exceptional skill. The drivers like Jones, Revson, Donohue, Posey, Savage were enlisted to pilot pony cars in Trans Am. The elite drivers called them "taxis" but they loved them. The cars were comparatively crude production-based and driven with what looked like abandon. It was brakes, power and guts. In a steel cage there was a faux perception of invulnerability. The SCCA club classes were similarly specified. The downside was fragility. The racing loads fatigued and yielded parts and challenged fasteners. Managing deterioration was routine. Real race cars were task-designed, more durable and more sophisticated.
Real race car parts and designs have trickled down into production based cars resulting in complex adjustments and fine settings.
I seperated from the USAF with a 1966 Shelby GT350. Surveying the WI autocross scene I found the Tri-State organization and the AMX team was very competitive. I joined to find FTD was usually the AMX team and specifically Chauncie Martin in his 289 powered Austin Healey 3000. After a year I sold my Shelby and bought an SCCA prepared GT350 to go Club racing. After my first (fall) driver's school I rebuilt the car and was late for my second school in the spring. I ran the more amature MidWest Council races through the summer. Chauncie was paying attention and prepped the Healey for racing. His first event was Blackhawk Farms, 1.9 miles, flat and ~110MPH straight. A good production car lap was 1:15. Chauncie qualified mid-pack but he disappeared when the green flag dropped. Post race he told me "I never thought I would not have enough power". I never saw him at the track again.
I find that era cars are more numerous at the vintage race events than they were back in the day. Not only is my race Shelby still out there, my street car is now a vintage racer. The displacement and power now is 20% to 30% more than I raced, but the lap times are similar or greater. The difference is it is a power event, passing on the straights, but not contesting corners. A great time is had by all.
Kit cars are something else. They too have "trickle-down" engineering and parts, making sophisticated chassis tuning possible for AX and/or track events. That 818/VIR video looked more stable than my Shelby was. Not a "taxi". jim

[Jim1855]

It's threads like this that encourage me to get my build completed. I've been lagging for too long, just didn't care. But now I really want to get moving and will.

For GT Bradley, there was an earlier comment about getting out of first gear, a wise recommendation. I run road tracks in 3rd & 4th, plenty of power, still a need to be mindful of power delivery but nothing like the lower gears. First gear is for leaving stop lights and lighting up the tires.

I wish more people ran some form of track events, it's the only way to find out just what the car will do. Can't get close to it on the street, at least not w/o threat of arrest. I did my first track event at Gingerman in 2004 just 6 weeks after putting my first Superformance on the road. It was "eye opening" to find out just how fast it was and how fast I could get into serious trouble. BTW, I've never been on a road track that I haven't fallen off of. There's just something special about agricultural excursions beyond how dirty a car can get.

Drive with wisdom and control, but hammer down...

Jim

[GTBradley]

Thanks Jim and yeah doing it in 2nd is going to change things big time, but I gotta say, with a Coyote, that RPM range between 4000 and 6000 is ultra-fun. It maybe better left for drifting? Anyway, I totally agree, the track is the way to enjoy the car to it’s fullest. I had no idea what I was missing until now. It helps too that autocross doesn’t generally risk damaging the car either.

Bradley

[NC Cobra]

Bradley,
I too am just getting started with the auto cross thing and have really enjoyed the discussions on the thread. I’ve posted a link here http://thscc.com/track-program/nonhtml/Notes%20for%20High%20Performance%20Driving.pdf that I have also found to be very informative. While the article is focused on HPDE and closed course oriented I think a lot of the concepts would transfer to AX. IE: keeping your head outside of the car, smooth inputs, and situational awareness.

BTW, like you I also picked up the heel stop kit from Breeze and hope to get it installed this week. I also found some knurled bar stock for the clutch side but need to find a band saw to split it prior to bolting it into the floor. I’ll let you know how it goes once I get it them into the car.
Cheers,
Jeff

[AdamIsAdam]

When I took my GT350 to the auto-x I tried it in first gear. With an 8,250 redline, I figured let's give it a shot. Well, as mentioned above, the drifting was fun but the times were no better, maybe even worse.

My Cobra's 347 has so much torque and it starts basically just off idle that I get it right into 2nd when I went. In fact, watch this video of that day. It was a nice day for Nov in NY, but it was Nov in NY so the tires never got really warmed up. It may sound like I'm riding the clutch and playing as I leave, but really that's tire spin. The clutch was engaged fully immediately.

As I said before, I love exploring the limits of the Cobra safely at the auto-x, but it stinks to be there all day for 10 minutes of driving.



https://youtu.be/XeZ0zhI_3PQ

[Avalanche325]

For track setup it really depends on how serious you want to be. Autocross too for that matter. Some guys come in on a trailer, keep log books, take temperatures, spray down the tires with ice water between runs, etc. Real deal racecars will even run different settings on each side of the car to fit the particular track. They also change shocks, springs and rear end gears for each track. If I were getting that serious, I would be getting a car with a full cage.

For HPDE track days, I leave it the same as my autocross / street setup. I am running 1/8" toe in. -2.5* camber, and -7* caster. I have a solid rear. One thing is that I do not run any rake. I pulled that 1/4" extra height out of the rear for more grip. I run 200TW tires which are a good do it all range and you can squeak 9-10k miles with an autocross a month and a couple track days a year. By the time I get some inside wear the tires are pretty much used up grip-wise anyway.

[GTBradley]

Bradley,
I too am just getting started with the auto cross thing and have really enjoyed the discussions on the thread. I’ve posted a link here http://thscc.com/track-program/nonhtml/Notes%20for%20High%20Performance%20Driving.pdf that I have also found to be very informative. While the article is focused on HPDE and closed course oriented I think a lot of the concepts would transfer to AX. IE: keeping your head outside of the car, smooth inputs, and situational awareness.

BTW, like you I also picked up the heel stop kit from Breeze and hope to get it installed this week. I also found some knurled bar stock for the clutch side but need to find a band saw to split it prior to bolting it into the floor. I’ll let you know how it goes once I get it them into the car.
Cheers,
Jeff
I got that heel stop installed, actually re-installed as the angle was wrong the first time. I love the position reference it provides already. My foot was moving around so much that on bumps it would cause a little surge on the gas. Thanks for the reading material.

[GTBradley]

When I took my GT350 to the auto-x I tried it in first gear. With an 8,250 redline, I figured let's give it a shot. Well, as mentioned above, the drifting was fun but the times were no better, maybe even worse.

My Cobra's 347 has so much torque and it starts basically just off idle that I get it right into 2nd when I went. In fact, watch this video of that day. It was a nice day for Nov in NY, but it was Nov in NY so the tires never got really warmed up. It may sound like I'm riding the clutch and playing as I leave, but really that's tire spin. The clutch was engaged fully immediately.

As I said before, I love exploring the limits of the Cobra safely at the auto-x, but it stinks to be there all day for 10 minutes of driving.

Yeah, I figure if the Miatas don't need a lot of power to get good times I certainly don't need to be running at max HP/TQ. Nice video! I remember seeing this back when you originally posted it and it helped motivate me to the course. That fast run did look the smoothest and the car looks very flat in the turns, I'm guessing you have at least the front anti-sway bar?

[GTBradley]

For track setup it really depends on how serious you want to be. Autocross too for that matter. Some guys come in on a trailer, keep log books, take temperatures, spray down the tires with ice water between runs, etc. Real deal racecars will even run different settings on each side of the car to fit the particular track. They also change shocks, springs and rear end gears for each track. If I were getting that serious, I would be getting a car with a full cage.

For HPDE track days, I leave it the same as my autocross / street setup. I am running 1/8" toe in. -2.5* camber, and -7* caster. I have a solid rear. One thing is that I do not run any rake. I pulled that 1/4" extra height out of the rear for more grip. I run 200TW tires which are a good do it all range and you can squeak 9-10k miles with an autocross a month and a couple track days a year. By the time I get some inside wear the tires are pretty much used up grip-wise anyway.

I saw some of that crazy stuff going on with some of the guys driving really high performance cars, I didn't know what they were doing, but it made me realize I'm not going to go that far. I'm just going to see how quick I can get with technique and with what equipment I have and eventually with better tires, alignment changes and possibly an anti-sway bar.

Just guessing here, but you mean 7˚ caster not -7˚, yes?

[BrewCityCobra]

As a fellow newbie to the motorsport arena one thing I did find (I too was looking for more track time per day than autox was providing) is HPDE or open track days. They provide a much larger amount of time on track (think 6 20-minute periods instead of a few 1-minute runs). You lose the competitive component/timing which stinks (unless you go time trials which is currently out of my league) but there is a bit more flow to the day overall as you repeatedly see the same corners over and over during a session and can adjust accordingly to learn how the car behaves. Downsides are increased costs, increased speeds, and increased wear and tear on the car.

Just a thought - I still attend and enjoy both styles.

[AdamIsAdam]

Yeah, I figure if the Miatas don't need a lot of power to get good times I certainly don't need to be running at max HP/TQ. Nice video! I remember seeing this back when you originally posted it and it helped motivate me to the course. That fast run did look the smoothest and the car looks very flat in the turns, I'm guessing you have at least the front anti-sway bar?

No sway bars. Very stiff springs which I actually changed for softer ones this winter because of our crappy NY roads. I can't wait to see how that changes the handling on the course.


As a fellow newbie to the motorsport arena one thing I did find (I too was looking for more track time per day than autox was providing) is HPDE or open track days. They provide a much larger amount of time on track (think 6 20-minute periods instead of a few 1-minute runs). You lose the competitive component/timing which stinks (unless you go time trials which is currently out of my league) but there is a bit more flow to the day overall as you repeatedly see the same corners over and over during a session and can adjust accordingly to learn how the car behaves. Downsides are increased costs, increased speeds, and increased wear and tear on the car.

Just a thought - I still attend and enjoy both styles.

I've done HPDE in many cars but won't do it in my cobra. A little too dangerous for me and also too far to travel without a tow vehicle and trailer. But you're right, SO much track time, it's great!

[CraigS]

In addition to being significantly more dangerous, 20 min on a road course is a whole other world for your car as far as oil and water and brake cooling.

[Jim1855]

In addition to being significantly more dangerous, 20 min on a road course is a whole other world for your car as far as oil and water and brake cooling.

Not to mention the wear & tear on you. 20 minute sessions of driving takes a toll. This isn't intended to diminish the bodily stress of the instantaneous changes in autoX.

On the street it's water temps in slow traffic. On a road track it's oil pressure and oil temps, you'll figure out quickly why coolers are necessary. And brakes - cherry red is pretty.

While I'm not an autocrosser, I'd guess that water and oil temps barely get to the normal range. Oil pressures may vary depending on time in a corner and pushing the oil to the ends of the pan. At 1G of cornering, which is fairly easy to do, the oil won't care if it's in the pan or valve cover.

It's all great fun, dangerous perhaps, but then so's sex, doesn't mean people are going to stop doing it. Whatever you choose you'll quickly figure out why the cars are so cool.

Jim

[BradCraig]

As a fellow newbie to the motorsport arena one thing I did find (I too was looking for more track time per day than autox was providing) is HPDE or open track days. They provide a much larger amount of time on track (think 6 20-minute periods instead of a few 1-minute runs). You lose the competitive component/timing which stinks (unless you go time trials which is currently out of my league) but there is a bit more flow to the day overall as you repeatedly see the same corners over and over during a session and can adjust accordingly to learn how the car behaves. Downsides are increased costs, increased speeds, and increased wear and tear on the car.

Just a thought - I still attend and enjoy both styles.

YES! I did the Charlotte SCCA Track night at CMS, highly recommend. The car performed amazingly, except for FF brakes. Wilwoods on the way and have another track night scheduled for June 5. As you said, not competitive but allows you to open it up to see what the car can actually do. I'll probably try Auto-x but I really don't get too excited about it, that may change one I try?

[mike223]

On a road track it's oil pressure and oil temps, you'll figure out quickly why coolers are necessary. And brakes - cherry red is pretty.

While I'm not an autocrosser, I'd guess that water and oil temps barely get to the normal range. Oil pressures may vary depending on time in a corner and pushing the oil to the ends of the pan. At 1G of cornering, which is fairly easy to do, the oil won't care if it's in the pan or valve cover.

Regarding the track, I recall reading somewhere that Shelby American's policy for differential oil coolers was any race over two hours - I can't imagine a transmission oil cooler would be very different.


Autocross is the only place I've gotten my oil temp all the way past water temp - met a guy a couple years ago (in another FFR roadster) who was using a carpet drying fan between runs to cool his oil pan.

Seemed to be working pretty well, but mine was only approaching the point where I would consider dragging all that around.


By the end of the second autocross run my oil temp will be well beyond water temp - I manually run the electric radiator fan on for 30-90 seconds after shutdown and preceding startup to keep it under control - but heat is definitely an issue in autocross.


And agreed - you need a good road race oil pan - because that quickly becomes a factor too - I had to polish the crank + replace all the bearings after the first season (high G oil pressure loss / no baffles in oil pan / etc).

[GTBradley]

Here's one I forgot to ask about and Jeff K just reminded me of on another thread: what about front tire size? I'm using a 255/40 but I've seen up to 275 used up front. Would wider be better?

[Rdone585]

Good question. Here are my thoughts on that topic. It depends on the tire and your car. Some cars may have clearance issues if they go too wide. Some tires have a different diameter with different widths also. A wider tire will be harder to turn if you have manual steering, so you will feel the difference after a long day at the track. It also takes a little longer to heat up a wider tire if you're doing autocross. So there can be tradeoffs to be made when considering which width to run.

[CraigS]

275/315 has been the standard setup for a long time. When FFR re-did the body for the MkIVs they made the front fender flares slightly smaller and added that 1/2 inch wide lip that extends toward the center of the car. This is when the 245s and 255s became more popular. Trimming that lip to zero helps a lot. Also the most common point of tire fender contact is at the front of the tire rather than at the top as one might expect. So just a little extra removed from the front of the flare fixes the problem. You can see how close the tire gets by turning the steering while sitting in the garage. On the left front tire look at about 9 to 10 oclock.

[AdamIsAdam]

If the car tends to oversteer, and if steering responsiveness is very good, is there a need to go to a wider front tire? I have 245's and the steering is so quick I would assume going to 275 would only make that worse. (rears are 315's). 17".

(I used the word "assume" on purpose since I'm just speculating, so, ya know. lol)

[mike223]

If the car tends to oversteer, and if steering responsiveness is very good, is there a need to go to a wider front tire? I have 245's and the steering is so quick I would assume going to 275 would only make that worse. (rears are 315's). 17".

(I used the word "assume" on purpose since I'm just speculating, so, ya know. lol)


Is the car easily balanced with throttle position in a steady state corner?

Where you can get in the corner, straighten the front wheels, and essentially guide yourself through the remaining turn with throttle position?


Not a power slide - tire slip angles.

This is the balance I am looking for first in one of these cars on the autocross course.


You should be able to get there on 315x245 or 315x275, but it may require different settings - starting with tire pressure.


You should also be able to get there with 315x315, but that's almost certain to require a change in spring rates (softer back or harder front / probably rearrange all the way around).

[AdamIsAdam]

Is the car easily balanced with throttle position in a steady state corner?

Where you can get in the corner, straighten the front wheels, and essentially guide yourself through the remaining turn with throttle position?


Not a power slide - tire slip angles.

This is the balance I am looking for first in one of these cars on the autocross course.


You should be able to get there on 315x245 or 315x275, but it may require different settings - starting with tire pressure.


You should also be able to get there with 315x315, but that's almost certain to require a change in spring rates (softer back or harder front / probably rearrange all the way around).


I dunno yet. I only auto-x'd the car once and it wasn't really warm enough to get the tires fully heated up. All I can say is every time I got on the gas the back tires spun pretty easily. The video I posted above doesn't really show just how loose the rear felt to me (except when I spun out ;) ). And when I spun out that was a fantastic lesson for me as I get to know this car. I went into a decreasing radius turn too fast, lifted, and was instantly facing the wrong way! Wahoo! And THAT'S why I went there, to learn stuff like that. I had no idea that the Cobra handles like an old 911.

Funny thing is: last week I was on some local main roads taking an exit ramp. It's wide and I typically take it pretty fast even though it's also decreasing radius. Well, as I entered the turn and was about the lift off the gas, my brain said "Hey, dummy, don't just lift while turning, remember what happened last time!" Since I didn't want to try and guide myself through it with throttle position as you said, instead I had the room to straighten the wheel and brake a bit, then get back into it and finish my turn. Much safer that way on the street. And I was very glad for the auto-X spinout! I can't wait to get back to the course as the weather gets warmer and learn some more, safely.

[mike223]

Since I didn't want to try and guide myself through it with throttle position as you said, instead I had the room to straighten the wheel and brake a bit, then get back into it and finish my turn. Much safer that way on the street. And I was very glad for the auto-X spinout!

Sounds like your approach is excellent.


I think it's important to get know how these cars feel when they're approaching the ragged edge - because the nature of the (super) car makes it surprisingly easy to get there by accident (they make things happen quick).


Autocross is absolutely the safest place to learn + polish those (perishable) skills.

[CraigS]

I ended up running 315 front and 335 rear and the car was always too loose. 800 front springs, a 1 inch Forte front bar, the front DA shocks adjusted really hard allowed me to get away w/ it for 2 seasons but my plan was to go back to a 295 fronts. I decided that the 40mm difference front to rear (275-315) had always worked and the 20mm difference (315-335) was not enough. But we moved and now autocrosses are all 2 hour drives each way so I am in a different car now. My gut is that 255 would be a little less capable but not terrible. If I had 255s and found I was too tight, I'd just crank in more front negative camber. Which reminds me, once the 315-335 was found to be too loose, I went from -3.25 (I had been running that for a long time) to -2.75.

[CraigS]

Mike and Adam, I could not agree more. Using an FFR to it's fullest performance can't be done anywhere but AX or track. Heck, even a Corolla driven at it's limit is way too fast for the street. Back around 2007 we were on the interstate in my wife's 2005 Accord. Came over a rise in left lane at 75 and everyone in front was nearly stopped. I hit the brakes, was looking at the mirror as well as in front, and saw the guy behind me gaining on me. So I go to the grass median to go around the guy in front of me and away from the guy behind. The guy in front had already tapped the guy in front of him and one of their plastic bumper covers was half way onto 'my' grass. So we pass 4 cars in the grass and my wife says aren't you going to stop. Heck no, this grass feels soft to me so we need momentum to keep from getting stuck. We finally ease back to the pavement, it's all behind us and fortunately it was all fender benders and no seriously shortened cars. It was all over in 30 seconds. So I pick the pace back up to normal. Wife is quiet for a minute or so, then makes a couple of comments, and ends up saying, how the he11 did you do that? I guess decades of AXs have paid off haven't they. Besides they are so much fun. I am 72 and still at it. Next one is in 9 days at an airport where I have never run. Can't wait.

[Jeff Kleiner]

Here's one I forgot to ask about and Jeff K just reminded me of on another thread: what about front tire size? I'm using a 255/40 but I've seen up to 275 used up front. Would wider be better?

Sorry, been away from the forum for a few days. I ran 255s for years (my original crappy Sumitomos and 2 sets each of Kumho XS and Nitto NT-01) then went to the 275 when I changed to Toyo R888R 2 years ago. I HATE a car that pushes and could could cross over from push to neutral to loose with a 2 psi front/rear split with the 255s. The 275s up front allow me to keep it a little loose (just how I like it) with even pressures f/r. Not entirely scientific since I changed to a different tire at the same tame as I upsized but it’s probably pretty safe to say that although the change isn’t dramatic there is more front grip. Same end result, just a different way of getting there.

Jeff

[mike223]

Wife is quiet for a minute or so, then makes a couple of comments, and ends up saying, how the he11 did you do that? I guess decades of AXs have paid off haven't they.

Classic story.

The car control I learned from autocrossing a Vega GT a few years in the early 1980s has served me very well over the years in very similar ways.



Interesting you couldn't find a way to get it settled down @ 335x315


I was pretty comfortable in my gokart on 315x315 V710s (after going to stiffer front springs).


Of course I probably should add I prefer them a little loose too.

[J R Jones]

Old Bull teaches young bulls? Yeah with experience there is also wisdom. At 73 I recognize my physiology is not what it was, and neither is my invincibility. However, when it comes to driving and/or flying, naturals exist.
If this thread has devolved into bench racing, read on.
In high school, the class I excelled in was drivers ed. One of my first on-road lessons was in January on snow covered WI roads in a 1964 Chevy Biscayne four door sedan, six cylinder and three on the tree. Two students in back; Mr McFarlane in the passenger seat. I was just into third and pressing for speed when the rear tires broke and swung to the right. Feather throttle, counter steer, recovery, all before Mr M could comment. Unlike my father he was cool about it.

Four years later I am just returned from a USAF tour in Asia and enjoyed Christmas leave at my folks WI home with a TX buddy Hector Rocha. We have to be at Selfridge AFB by morning. "There are 300 miles to Mt Clemons, we have a full tank of gas, half a pack of cigarettes, it's snowing and we're wearing sunglasses." No problem, this is a '66 Shelby GT350 and I am invincible.
There is a phenomenon at the base of Lk Michigan called "lake effect". The snow can be and was, wet, heavy and deep. On I-94 there are no snow plows in sight.
Following an 18 wheeler at 60MPH the pavement is wet strips with a snow berm under the car and snow berms between lanes. The tire spray is filthy and annoying, I go for a pass and traverse the berms into the left lane. Accelerating on the wet I pass the truck and attempt a lateral back into the right lane. The front tires are deflected to the right by the center berm and the rear comes around to the left. Hector and I stare out the right window at a huge chrome radiator shell with KW at the top. I hear "Hail Mary Full Of Grace". Both axles are now on the wet paths as I steer left with the throttle feathered, but not closed. Simultaneously the front went left and the rear fell in line. Other than profanities, I do not remember much discussion.

As mentioned earlier in this thread, that Shelby was later autocrossed, but not always on pavement. Ice racing is popular in WI and the SCCA had a winter event on Browns Lake near Burlington. That was a treat given the course length and speed. The main straight paralleled an island. With four snow tires I saw triple digits, when I could focus on the heaving speedometer. jim

[Avalanche325]

a Vega GT

If that won't make a Ford man out you, nothing will. My first TWO cars were Vegas.

I'm surprised that there is a mention or high oil / water temps during autocross. I have never seen anything past normal street temps. Even on a road course autocross. I live in northern FL. I run a little hotter on the track of course.

One thing, for both autocross and track, warm the water / oil up before your session. That includes if you take a break and have an afternoon session.

I am also in the loose is better than tight camp. You can get the car to do either depending on the situation. I find that the car is pretty easy to adjust with the throttle, but you have to be smooth with it. Everything happens faster with a short wheelbase.

I highly recommend autocross before open track. You want to exceed the limit and spin or plow straight through a turn with cones, not concrete and armco. I always always try to drill through my head not to go over 9/10s on the track. 10/10s is for autocross only.

SCCA Track night in America is a good way to get on track for the first time. Inexpensive, and not too many sessions for the first time. Like stated, it will wear you out the first time. Not just muscles, but 110% concentration makes you tired.

[mike223]

If that won't make a Ford man out you, nothing will. My first TWO cars were Vegas.

They actually worked pretty well, I was usually beating all the Corvettes.

It was all fun + games until you scuff an aluminum cylinder wall.

Early eighties I was buying them (cheap) just for the engine - when I could find one that didn't smoke...

[mike223]

I'm surprised that there is a mention or high oil / water temps during autocross. I have never seen anything past normal street temps. Even on a road course autocross. I live in northern FL. I run a little hotter on the track of course.

I'd say I run autocross 9/10s - maybe 10/10s on the last couple of runs.

I rarely get oil temp up to water temp out on the road, but by the second 50-60 second autocross run it will be 10 degrees (F) above water temp, which I consider Ok.


I put an oil temp gauge on a Pinto (2300cc) I had in the Navy. It rarely got oil temp up to water temp - took at least 30-40 minutes of interstate driving to get there on a warm day.

Driving back east from the west coast it cooked the oil pulling up the continental divide (approaching 300F) - had to pull over and give it a rest around 5500', and again somewhere around 65-6700'.

A lot of people say oil temp is rpm based - I say it's load based.


I have no need for an oil cooler for autocross - but I'd be watching it like a hawk if I was driving 7/10s for 20 minutes on a road course.

[Avalanche325]

One thing is that it seems like every car is different when it comes to cooling. Some guys with a 347 complain that the overflow tank is too small. It has been fine for me. Others seem to want to overheat. I haven't had an issue. So, definitely keep an eye on it to see what your setup needs.

What I have for autocross / track is an idiot light that does dual duty high oil temp / low oil pressure. There is zero time to look at gauges during autocross.

Vega - mine got so bad (pitting around the top of the cylinders - open deck design) that when I started the car, it would pump water out of the exhaust before starting. Then take about 10 minutes to get all four cylinders firing leaving a trail of steam down the road. I used to keep 5 gallons of water in the trunk. If you revved it, you could shoot water about 6ft out of the radiator with the cap off.

[J R Jones]

Engine oil is most efficient when it is warm/hot/thin. OEM oil recommendations have been getting thinner. The oil must get to 220F to burn-off water vapor and deposits. The upper range for engine oil is 230 to 260F. Mineral oil will start breaking down at 275F, synthetics will go to 300F.
jim

[AdamIsAdam]

I converted over to Evan's Waterless Coolant. Jay Leno converted me. The stuff boils at 375*! And it doesn't expand nearly as much and the system is almost under no pressure. They suggest replacing your radiator cap with a lower PSI cap. I like the comfort of knowing my old style engines won't blow a hose if I get stuck in traffic in the summer. As for the FFR overflow tank, it likes to be about empty when cold. When I first got the car I added some and it puked it out. So I let it stay where it settled. That was before converting to Evan's. So with the less-expanding Evan's I'm sure my overflow size tank is fine now.

[GTBradley]

My 2nd autocross is tomorrow and I have made a plan on how to approach it. I’m taking input from the technique approach offered on the first page of this thread and will leave equipment changes and alignment settings for later. I’ll report back on my results.

Autocross notes


Get to 2nd gear soon after leaving the starting gate and stay there - this reduces abrupt inputs and deceleration braking caused by 1st gear, which are resulting in snap oversteer.
No sudden inputs on brakes, fuel, steering. This will reduce the rate of weight transfer.
Left foot braking - this allows for more control on turn in and coming out of a turn. I expect this to be disastrous at first, but I need to learn it early.
I have installed a heel stop in front of the gas pedal - I’m hoping this will help with throttle control - it certainly has on the street.
I’m going to try 20 psi on the tires and use chalk on the sidewalls to see what the contact area is at that pressure.
Accelerate all the way to braking, no coasting.
Be tidy, not fast and get closer to the cones.
Practice with knowing where the tires are on my 45 minute drive to the course, i.e., touching the rumble strip on the shoulder of the highway.
Make notes.
Have fun!

[AdamIsAdam]

HAVE FUN! looking forward to your next post.

[Jeff Kleiner]

My 2nd autocross is tomorrow and I have made a plan on how to approach it. I’m taking input from the technique approach offered on the first page of this thread and will leave equipment changes and alignment settings for later. I’ll report back on my results.

Autocross notes


Get to 2nd gear soon after leaving the starting gate and stay there - this reduces abrupt inputs and deceleration braking caused by 1st gear, which are resulting in snap oversteer.
No sudden inputs on brakes, fuel, steering. This will reduce the rate of weight transfer.
Left foot braking - this allows for more control on turn in and coming out of a turn. I expect this to be disastrous at first, but I need to learn it early.
I have installed a heel stop in front of the gas pedal - I’m hoping this will help with throttle control - it certainly has on the street.
I’m going to try 20 psi on the tires and use chalk on the sidewalls to see what the contact area is at that pressure.
Accelerate all the way to braking, no coasting.
Be tidy, not fast and get closer to the cones.
Practice with knowing where the tires are on my 45 minute drive to the course, i.e., touching the rumble strip on the shoulder of the highway.
Make notes.
Have fun!


Sounds like a good plan however I might start with a little more pressure, say 22-23 and then adjust down accordingly as they heat up and you see what the car is doing...if it's loose bring the front down 1-2 or if pushing bring the rear down 1-2.

Whatever you do make sure that you fulfill that last bullet point :cool:

Jeff

[GTBradley]

RMR Porsche club autocross event #2 - video (https://vimeo.com/557272798)

https://thefactoryfiveforum.com/blob:https://thefactoryfiveforum.com/217ceaa7-e4b0-40e0-9012-1a0ae5f06055
148841

Last bullet point fulfilled! We had a cool day that threatened to rain all day but never did, so it turned out perfectly. Though, I was interested to see how my tires would perform in the wet stuff as it is very common for the other drivers to have the sticky aggressive type, where I only have the Nitto 555s, which are just a performance summer tire.


The plan was stated above and I mostly stuck to it at least for half of the runs, but I altered my procedure back and forth through the day. Here are my impressions and results.




Second gear - it is intended to be easier for throttle control, but as I found out it is very track dependent. The last AX was a fast track and 2nd gear would have helped, but this track was short legged and took a full 10 seconds longer to complete even though it was laid out in the same space. Half of my runs were in 2nd gear and half in 1st and the fastest times were all 1st gear runs.
No sudden inputs - I did my best but this is very dependent on experience, so I’ll keep at it. My biggest issue was heavy late braking.
Left foot braking - overall this was a wash as far as my times go, but I do consider it a success because the learning curve wasn’t as bad as I thought and it will be helpful later to shave tenths of seconds off my time. Right now I need to shave multiple seconds.
Heel stop - I highly recommend this, it does actually stabilize my foot and throttle application.
Tire pressure - this may have been an issue at 20.5 psi considering our ambient temperatures were in the mid 60s. I’ll probably go back to 22 next time.
Accelerate to braking - I tried to accelerate all the way to braking but I wasn’t braking soon enough on hard turns. And I also found that sometimes it’s hard to continue accelerating or start braking yet. It still isn’t coasting but more a steady state throttle that carry’s you through the section to the next braking for a turn.
Be tidy, not fast - I have a lot to learn, I think. It turns out my messiest runs were the fastest ones and the tidy ones were the slowest. I suspect it is a balance between the two that gets the best times?
Being close to the cones - Cones…schmones! I’m too busy with everything else to do anything different there. However, judging from the videos I think I did alright and yes, I did tip a couple. I even hit one without knocking it over.
Notes - check!
Fun - check-check!



My performance improved over last time judging by my placement: 47th out of 75 this time and 48th out of 71 last time and there were a lot more first-timers last time. It’s not a major improvement, but it’s something.


I had hoped the course would be the same this time to compare, but it had roughly twice as many direction changes and that leads me to think that it favored cars with better tires and suspensions. There were no long straights this time. This is also why I think first gear was an advantage this time. RPMs topped out in the high 4000 range where last time I was in the high 5000 range, both in 1st gear, of course.


I had sloppy runs on my fast times with major understeer brought on by late braking. I could have saved significant time had I not done that on a number of turns. I didn’t include the tidy runs in the video, just the fastest ones with the most mistakes. The second video is a bad one as the video camera is tilted down, but there are things to see there and it is the fastest run, but I tipped a cone so it doesn’t count.


All in all, a good day, but I did find that I was frustrated that I couldn’t change my time significantly throughout the day. I did only have one DNF, so that’s an improvement. I can’t help but feel that the tires and possibly the anti-sway bar would have made a big difference on this track and I’m leaning toward doing one or both of those improvements sooner rather than later now.


Let me know what you think.

[D02G]

Very cool

[Jeff Kleiner]

I still say it's pushin'

Jeff

[J R Jones]

Brad, I feel bad that perhaps you had information overload. In an effort to maximize effect maybe you initiated too much at once.
Among things I am not is an educator, but a suggestion is a list of techniques to learn and a series of steps. Tape one or two steps to the dash as priority on that run.
Yes if a prior step becomes a natural response, fine, but focus on one or two things per run.
It looks like you are running in fast company.
jim

[GTBradley]

I still say it's pushin'

Jeff

I agree. And you suggest more seat time, right?

[GTBradley]

Jim, I just chose the things I wanted to focus on. It wasn’t really more than left foot braking, accelerate to braking and smooth inputs. I’m not good at those things yet but I did feel I improved some.

It is some fast company. The guy with the best time was in a 2020 718 Porsche GT4.

[AdamIsAdam]

Glad you had fun. Sounds like the course was very tight.

I hear more seat time can help 😁

[CraigS]

That is a shame the course was so tight. I hope they get another designer for the next one. I think you have diagnosed your driving quite well. Being king of the late brakers doesn't work so well as you found out. Long ago a friend made this point. On any given turn you have to give it up somewhere. In autocross, slightly erring on the side of going in too slow is always better than going in too fast because the center of the turn will be faster and so will the exit. What makes it so hard is the sound at full throttle is sooooo good. Here is another concept, trail braking. For me what this means is you don't fully release the brakes until a little later. IE; you don't go from 100% brake to 0% brake. You come off the brake pedal more like 100%, 75%, 50%, 25%, 0%. Why does it work? A tire has a certain amount of traction. There is a slight difference but, for the sake of discussion, let's say that traction is available in all directions. On corner entry you will transition from full brake traction to mid corner full cornering traction. So in the above listing of %s, more detail would be 100%B (brake) has 0% C (cornering). 75%B = 25%C, 50%B = 50%C, 25%B = 75%C, 0%B - 100%C. It's is similar but opposite to adding throttle on corner exit. You can't just slam down the gas pedal, you have to squeeze it on.
Trail braking is quite hard to get right, but when it happens it is magic. The next time you go in too fast, instead of coming off the brake all at once, hold partial brake for an additional 30-40 ft. One more thought. Better tires will get you better times but can actually be detrimental to building skill. I would experiment w/ bars or springs before going for better tires.

[Jeff Kleiner]

RE: Craig's education on trail braking (which is excellent)---this is where left foot braking comes in because you can work throttle and brake against one another as sort of a "buffer". I bet if you watch some of the fast guys you'll see their brake lights are on even when they're coming out of turns and accelerating. There is a learning curve...I resisted for a long time but as soon as I got serious about doing it there was a "Where have you been all my life" moment!

Here's another explaination of the "Traction Circle" Craig is talking about:


https://youtu.be/JjCcFsGLpaM

Jeff

[J R Jones]

Brad, After sleeping on this:
The "friction circle" was first described by Mark Donohue in the seventies. Maybe the method was used before then, intuitively.

This course adversely affected your strategy which suggests a pre-race effort was appropriate to formulate a "game day plan". We discussed previously the optimization of corners to take advantage of the the straights. In the absence of straights, the strategy changes. You attack chicanes differently than corners coupled to straights. Your course description suggests this was a series of chicanes and slaloms. Perhaps the key on this course was maintaining and modulating a somewhat constant speed and throttle/brake control vs accelerating from corner to corner. Visualize minimized pitching with optimized rolling from corner to corner. Less drama, more control.

Another issue....it is easier to identify your acceleration point from steady state, than it is from acceleration, simpler dynamics. You did not mention apex. Perhaps you should prioritize transitioning from throttle to brake to nail your apex under control, then identify enough stability to accelerate. Too much entry speed?

You write: "understeer brought on by late braking". I do not understand, the tires slid after you initiated braking? Is that brake proportion? Weight transfer to the front loads the front tire treads. Do you have ABS?
Maybe you just exceeded the traction with too much braking and steering at the same time (friction circle) but realize this was caused by too much corner entry speed.

Consider optimizing you ability to control and maybe adjust this configuration before you modify it with anti-roll bars. That will make evaluating the changes more valid. Setting up the car is a higher priority, and not the same thing as modifying it.
jim

[J R Jones]

I could not previously view the video, I just found a way. One video is worth....Jeff is right it sounds like the fronts are screeching often, even steady state turning. I feel the tire pressure is low. The front end seems unresponsive.
What kind of power steering is that? Is there feedback? What is the steering ratio? What is the source, Mustang?
10 - 2 steering discipline! Don't let your wrists cross.
Why do you not have a front A/R bar? Is that the default build? WT?
Is your brake proportioning optimized?
I do not like the roll bar video, is that on a gimbal? I can not relate to that perspective.
My cars are very different from this.

[GTBradley]

That is a shame the course was so tight. I hope they get another designer for the next one. I think you have diagnosed your driving quite well. Being king of the late brakers doesn't work so well as you found out. Long ago a friend made this point. On any given turn you have to give it up somewhere. In autocross, slightly erring on the side of going in too slow is always better than going in too fast because the center of the turn will be faster and so will the exit. What makes it so hard is the sound at full throttle is sooooo good. Here is another concept, trail braking. For me what this means is you don't fully release the brakes until a little later. IE; you don't go from 100% brake to 0% brake. You come off the brake pedal more like 100%, 75%, 50%, 25%, 0%. Why does it work? A tire has a certain amount of traction. There is a slight difference but, for the sake of discussion, let's say that traction is available in all directions. On corner entry you will transition from full brake traction to mid corner full cornering traction. So in the above listing of %s, more detail would be 100%B (brake) has 0% C (cornering). 75%B = 25%C, 50%B = 50%C, 25%B = 75%C, 0%B - 100%C. It's is similar but opposite to adding throttle on corner exit. You can't just slam down the gas pedal, you have to squeeze it on.
Trail braking is quite hard to get right, but when it happens it is magic. The next time you go in too fast, instead of coming off the brake all at once, hold partial brake for an additional 30-40 ft. One more thought. Better tires will get you better times but can actually be detrimental to building skill. I would experiment w/ bars or springs before going for better tires.
This makes total sense to me as we use the same concept in flight, as in, you can't have it all. In level flight you get all the lift but in a bank you share the lift with the turn, i.e., horizontal coefficient of lift. I'll simplify this one to brake sooner and don't come off the throttle suddenly, when it's time to start accelerating don't come off the brake suddenly.

[GTBradley]

In the video where he says, "you can't go right back to the static frictional coefficient" [by backing off a little], is so true and what I was doing was causing the unstick condition with heavy, late braking and starting the turn. I knew this, but as was mentioned by Craig, the throttle sounds sooo good, and truthfully the aggressive approach was lowering my times but limiting my improvement by wasting time trying to regain traction. This is where you start to rationalize that better tires would be so helpful, but this discussion makes it more clear to me that less sticky tires will help me understand the dynamics I'm dealing with.

I'm getting a lot of, "you're doing really well for not having ASBs" from other drivers at the track. And it sounds like they might be the first improvement to make to the car, so would it hurt to add those now? It sounds to me like the car could benefit from the back one to help with the "push"condition. Would it be detrimental to learn these braking concept with the ASB installed?

Edit: I just found this late 2017 discussion on suspension setup (https://thefactoryfiveforum.com/showthread.php?26802-%93I%92m-a-believer%94-in-anti-sway-bars). Jeff, I just realized you aren't using anti-sway bars, or is that still true?

[GTBradley]

I could not previously view the video, I just found a way. One video is worth....Jeff is right it sounds like the fronts are screeching often, even steady state turning. I feel the tire pressure is low. The front end seems unresponsive.
What kind of power steering is that? Is there feedback? What is the steering ratio? What is the source, Mustang?
10 - 2 steering discipline! Don't let your wrists cross.
Why do you not have a front A/R bar? Is that the default build? WT?
Is your brake proportioning optimized?
I do not like the roll bar video, is that on a gimbal? I can not relate to that perspective.
My cars are very different from this.
I have the FFR supplied mustang power steering rack and don't know the ratio. I have installed the lowest boost valve that KRC offers for their PS pump. There is feedback but the steering is sensitive. No front or rear ARBs as I din't opt for that option until I could feel the car out without them. I am leaning towards installing them and leaving the front or back disconnected alternately to discover the benefits individually. Brake bias is to the front in my opinion and I do have the balance bar adjuster knob installed but haven't played with that much yet - thanks for reminding me. The gimbal was my head. I won't do the helmet cam again as it only works if you don't bump it bringing the shoulder harness overhead. I now have a suction mounted stalk on the rear deck.

[CraigS]

Yep good F to R brake balance is another of the finer points of autocross. My method; 40mph on a level road (watch for the crown) hit the brakes. Keep adding one more click of rear brake until you get rear lockup. The first time it happens you will understand why I say 40mph and no faster. It is actually sometimes hard to feel because the diff tends to try to keep both rear wheels going the same speed. When the rears lock you may feel the engine being stopped for an instant. So when the rears lock first go one click to the front and maybe one more. The good thing about bias adjustment is you set it for good optimum dry conditions. In any less conditions, you can't brake as hard, so less weight transfers to the front so the fronts will tend to lock first. Fronts locking first is what you want on the street because it is stable. You may even change adjustment by a click or two for AX and then back for the ride home. In a way though this proper adjustment is not really about locking the brakes, it is for braking at 98%. Testing when they lock is just a technique we can use. The real benefit is to use the brakes to rotate the car. Like trail braking, when you get it right, it is a wonderful thing.

[Mike N]

On any given turn you have to give it up somewhere.

If you can find out who the course designer is they can often give you good insight into where you need to 'give it up'. The course designer in the NNJ group I used to run with would often tempt you to run fast into a series of gates where in reality it would yield a faster time to give it up going into the first gate to get a much better line through the series. All part of the fun of Auto X.

[RoadRacer]

Yep good F to R brake balance is another of the finer points of autocross. My method; 40mph on a level road (watch for the crown) hit the brakes. Keep adding one more click of rear brake until you get rear lockup. The first time it happens you will understand why I say 40mph and no faster. It is actually sometimes hard to feel because the diff tends to try to keep both rear wheels going the same speed. When the rears lock you may feel the engine being stopped for an instant. So when the rears lock first go one click to the front and maybe one more. The good thing about bias adjustment is you set it for good optimum dry conditions. In any less conditions, you can't brake as hard, so less weight transfers to the front so the fronts will tend to lock first. Fronts locking first is what you want on the street because it is stable. You may even change adjustment by a click or two for AX and then back for the ride home. In a way though this proper adjustment is not really about locking the brakes, it is for braking at 98%. Testing when they lock is just a technique we can use. The real benefit is to use the brakes to rotate the car. Like trail braking, when you get it right, it is a wonderful thing.

Craig, thanks for this. I'm chatting about balance bar in another thread but since I'm doing my own first AX in 3 weeks I'll post to this thread too since it's relevant. How easy is it to lock brakes? I just rebled my car, and tried at 35 and 65mph and although the car seemed to stop very quickly, there was no lockup. I could have pushed harder or more violently but that doesn't sound a great idea :D. But if it should be easy to do, then maybe I need to get out and bleed some more. How does width and stickiness of tires factor into this? Seems it would be easier to lock up thin tires, but I'm not sure I understand the interplay between brakes and tires.

[GTBradley]

If you can find out who the course designer is they can often give you good insight into where you need to 'give it up'. The course designer in the NNJ group I used to run with would often tempt you to run fast into a series of gates where in reality it would yield a faster time to give it up going into the first gate to get a much better line through the series. All part of the fun of Auto X.
Unfortunately, this was a course design contest. I don't think anyone thought it was that great and expect they will return to the more normal course in the future.

[GTBradley]

Craig will give you the straight poop on this, but I can tell you from experience with wide tires and the big, Wilwood brakes it will lock up as soon as you want it to. The typical response to someone having trouble with lockup, after you investigate other issues like bleeding the lines of course, is to change the brake pads to something more aggressive.

[J R Jones]

Sensei say "Be one with your tires Grasshopper". Not that everyone can. Like a professional your senses must detect the subtleties unknown to most; one can sense the tire contact patches individually.
As an adolescent I was trained at a dealership to evaluate cars before and after repair. I did as many as 35 per day. Tom McCahill called it "sandpaper arse".
When we raced across Mexico in La Carrera the speed stages were flat out on (closed) public roads. Like a rally you discover and experience simultaneously. At 9 or 10 tenths I could feel the contact patches loose traction as we crossed paint lines on the pavement, sweeping road edge to road edge. The sensing technique is most beneficial when you interpret it at the onset of grip loss, before control loss. In the friction circle concept, the contact patch "static frictional coefficient" is compromised by the tread going slick and the tarmac fragmenting. The tire has to roll to stability with less induced load.
Scrub angle similarly plays into friction circle grip as experienced in understeer. Then the steering angle to travel angle exceeds 6-7 degrees the contact patches slide and greater steering angle has no effect. Getting under the 6-7 degrees gives the contact patches a chance at regaining traction. Pitching weight forward with the brakes would increase load on the contact patches, but if they are sliding recovery of frictional coefficient will be delayed and braking effect is also muted. Goodbye cones.

[CraigS]

It should be relatively easy to do. Mine take more effort than my Tacoma but not a ton more. As with other physical efforts, when you get to where you are using a high % of your maximum strength, your fine control goes to he11. If it isn't, as you can see in many threads, better pads is usually the answer. I am not real familiar w/ the 33 brakes but I am sure there are others in that sub forum who are.

[J R Jones]

I have no knowledge of 33 or Cobra brake configuration, maybe there is cause to be concerned.
On my 818 the default is the Subaru donor brakes. Option is a Wilwood kit which I have. A racer in OR has had brake issues and discovered the Wilwood upgrade has been listed incorrectly content for years. They list 1.25 thick rotors, 0.81 are supplied.
Looking at my car, the previous owner installed the 12.19 dia rotors in front (as I would) and they fit the pad radius perfectly.
The other two rotors are 12.0 diameter which fail to cover the rear pad radius by about 0.19. As I see it the larger rotors should be front and rear.
More troubling are the small pistons (1.0) in the rear and 1.62 in the front when the weight proportion favors rear. The proportioning valve is plumbed to the front(?).
Again the calipers should be closer or the same front and rear. I have lots of work fitting an alternative body and cooling system. I will get to brakes later.
jim

148953148954

[Avalanche325]

I think someone new should not be left foot braking or trail braking.

Using one foot gives that 10th of a second to let weight transfer. I talked to a national champion that never left foot brakes unless he is driving an open wheel car. Leave trail braking for long sweepers and big turnarounds.

You should concentrate on braking in a straight line, coming off brakes and then turning in. That will help you find the maximum braking and the maximum turn in. Trying to combine it will slow down your learning curve. 99.9% of the time beginners are trail braking too much and costing themselves time. I went to an SCCA Starting line school years ago. We were running laps around an oval for the very purpose of learning not to turn in until you released the brakes. The instructor would hold the wheel straight until I released the brakes. I didn't realize how much I was trail braking when I shouldn't have been. If you are pushing....trail braking is going to make it worse.

My advice from watching your video. I am not Mario Andretti, so take it for what it's worth. You are doing great by the way, so this just my idea of helping out.

Hand placement on the wheel. Your hands are constantly changing position. That doesn't allow your brain to reference steering center, where you are in the turn (wheel position-wise), or how much force is needed to turn (different leverage depending on hand position). Start at 9 and 3 and if you need to turn past 180*, do a hand cross over. Always back to 9 and 3. Never shuffle steer. Controlling a car is hugely about muscle memory. You need set reference points for that.

Look further down course. It appears to me you are sometimes running to the apex cone, then taking action. When you get to the element entrance cone, your brain should already be past the exit cone. I think that will help with a couple overshoots. I still actively work on my sight lines when I walk the course. I literally point to where I should be looking at different points on the course. Sometimes I even remember to do it when driving.

I am glad you are having fun. I just got back in a couple weeks ago after being off for a while due to isolating.

[GTBradley]

Well there is a honest difference of opinion on left foot braking. Different philosophies, I suppose. Thanks for the different take and like I said it wasn't helping or hurting my times that much, so I can go back to left foot if needed. It is quite an advanced technique. It was interesting to see that I had decent control with my left foot, but it is entirely possible that I was pressing harder on the brake than I would have with my right foot.

I was braking straight ahead before and know intuitively that you shouldn't turn while braking hard, but I was breaking loose with the front tires first and then overrunning the turn, but only on those aggressive runs. I'm suspicious that the low tire pressure and my brake bias caused part of the problem, so I'll fix that before the next event.

I was wondering about hand placement, I didn't anticipate moving my hands at all, but there were some really tight turns. I'll do the 9 and 3 position next time.

It is definitely good to be back to doing things outside and with other people. Thanks again.

[Avalanche325]

Left foot braking may work fine for you. However, for most people, it is something new that has to be learned and you are already learning a ton of new skills.

You mentioned a heel support. I read a really good article about large vs small muscles, I can't remember were it was. Basically that you should be using small muscles for car control. For instance, keeping your heel on the floor and using your smaller fine control ankle and foot muscles rather than foot in the air which uses your big sledgehammer quadriceps. Sounds like you are onto that one already.

I use the same method as CraigS for setting brake bias.

[J R Jones]

Brad, This AM I read discussion on the 33 Hot Rod thread about tire pressures. I am still skeptical about the recommendations I have read, but light street cars with fat street tires is not my expertise.
NAZ from Flagstaff is technically brilliant on many topics, and offered this video on measuring tread temperature and making data based adjustments. Well worth a look:
https://www.youtube.com/watch?v=WGm_dvrJd2E
Been there, done that.
The metrics are there for pressure, and may be relatable for camber.
jim

[Jeff Kleiner]

Measure temps if you like but after making several hundred runs I can tell you what works...Nitto NT-01 and Toyo R888R like 20-22 and Kumho XS want 18-20. Rivals are the oddball and do best at 26-30. Depending on temperature, surface and your handling preference you may end up with a 1-2 pound front/rear split.

Jeff

[GTBradley]

Thanks, Jim it’ll be interesting to see if this matches what I’m already doing.

[GTBradley]

Measure temps if you like but after making several hundred runs I can tell you what works...Nitto NT-01 and Toyo R888R like 20-22 and Kumho XS want 18-20. Rivals are the oddball and do best at 26-30. Depending on temperature, surface and your handling preference you may end up with a 1-2 pound front/rear split.

Jeff
But you guys said I can’t have those tires yet. I think I have 18 more AXs to go before I’m even worthy of sticky tires…

Seriously though, I have another reason to wait. I don’t want to throw out my 555s until I’ve gotten the wear out of them and a spare set of wheels can’t even be bought right now, or so I hear. Anyway, it’s good to have these numbers for future use.

[NC Cobra]

Brad
Finally got my first autocross in yesterday. Gotta say that is about as much fun as you can have with clothes on. I really enjoyed the chance to push the car and see what would happen. Course was quite fast with several decreasing radius, off camber turns to keep your attention. Temps were mid 80’s, with high humidity so the Nitto NT 01’s were super sticky. Coming off a set of 4.5 year old MT Street Comps the difference between the two was dramatically apparent. I found myself intentionally pushing the car beyond where I normally would have and it just kept asking for more. Several times I pushed it too hard into a corner, the car would start start softly understeering, and just I would lay into the throttle to rotate the car through the corner. It was amazing, almost like the car talked me through what it wanted. I am thoroughly impressed with what this car can do.

That having been said the weak link in the system is definitely me and I can clearly see that the tires were covering up a multitude of sins. However Number one for me needs to be recalibrating my focal point as I’m driving. Turns were coming up very quickly and as my focus has always been on being smooth in my driving. As a result, I found myself looking too far down course and aiming for a gate too far down the course. The result was that I had to make very aggressive steering inputs when I saw the upcoming gate or miss it all together. Shocking how quick it comes at you; but also surprising how responsive our cars are.

Next thing I need to work on is accelerating up to the braking point. I spent too much time coasting rather than pushing the car into the next maneuver. Part of that was learning how fast I could negotiate the slalom sections, but honestly I think most of it was the lack of navigational skills discussed earlier. I had several “what the heck is that” moments I’m embarrassed to say.

Finally, once I get my feces consolidated as to where I’m going, I think I need to work on being smoother. I was able to put together one run where I seemed to have a better handle on the course and could focus on connecting the turns. While my lines were a bit “rounder” it was much smoother and I didn’t scrub off as much speed in the turns as a result. Really felt the flow of car around the course and wound up shaving 3 seconds off my time.

Ultimately I think I the car is pretty much where I want it and I’m going to limit the changes for the next event to tire pressure. I intentionally left everything in full street mode as a starting point yesterday and I think that tire pressures were a bit too high, especially given how hot it was.

Thanks very much to all who have shared your thoughts and knowledge here. I’m looking forward to learning more for sure!

Cheers,
Jeff
149194

[NC Cobra]

149219149220149218

[GTBradley]

Nice! Glad to see someone else new getting into it. That course looks like it might be challenging, how long did it take to get through it?

By the way, the temp thing seems to work. After a long drive yesterday I tried it and at 22 psi and my temps were consistent in all locations across the tire. I'll try at the next autocross this Saturday too.

[CraigS]

A technique I have found useful is to visualize the shape of the entire course. Not always possible because of the layout but I do my best. You walk it as many times as you can looking at individual and small groups of corners. But then go to the start line and overlook all of it. Maybe the course is like a letter 'M'. Starting on the left, running up that side are 3 offset gates, the first set of right turns is pretty tight, the middle left turn is more like a big 'U', the top right turn is a decreasing radius and a slalom to the finish. This helps me get an overall picture so 1, I don't get lost, and 2, I can plan ahead but not too far ahead. A tip on slaloms; As you walk count steps between slalom cones. The number doesn't matter, but you want to know if the distances are the same or possibly decreasing. When you run the slalom, if they are constant spacing, you hold a steady speed w/ constant throttle. If you are on/off the gas you change the tire's loading and hence their traction w/ each pedal move. NC, I once gave a ride to a fellow AXer who did a great job in his Miata. His comment after was something like, OMG, I had no idea how fast things are happening in your car.

[NC Cobra]

Thanks for the insights Craig. This course was so long I think I might have run out of alphabet before the finish trying to memorize all of it. Think one of my favorite sections was a long 50 mph straight with slalom gates. The fast guys looked to be using the turns to reduce speed going through it (no brake lights) which was important because the last 2 gates got shorter, and led into a left offset, hard right turn. The sneakiest part was that the gate opened up into such a long, lovely, & fast sweeping turn. Really hard not to carry too much speed into the trap looking forward to the fun ahead. As they used to say “patience grasshopper.” Tires got me out of that one a couple of times but it certainly will open your eyes in a hurry!

[NC Cobra]

Brad, My best time was a 81 second lap with most around 84 seconds. Best novice was a Caymen GT4 at 68, top CAM cars were Vettes at 63, and the fastest was a highly modified Lotus Elise at 55 seconds! Clearly I have a lot to learn but on the positive side I am having a lot of fun doing it! Good luck on your next outing and please let us know how it goes.

[J R Jones]

Brad, On temperature: With friction comes heat and with heat comes pressure. Road driving creates relatively little friction or heat, mostly from sidewall flex. The rears experience more friction but less weight.
When we take tire temperature at the track it is as soon as the car gets to the pit. The last turn skews the data with side-friction. Turn 14 at Elkhart (right) would heat the left edges of the tires, so a bit of rationalization was required.
NC, Part of my career was in the marine industry developing jet pumps. Jets are popular for rivers in Australia, New Zealand and the US NW. One racing class is Jet Sprint with 14 foot aluminum hulls and 750-1000hp. I have ridden at events near Boise and on the Rough River. The slalom course and speed is so violent there is a spotter to direct the driver to subsequent turns. Ever see a boat with a roll bar? Hold your beer and watch this:
https://www.youtube.com/watch?v=buaBCmWj_KM
jim

149223

[NC Cobra]

Yup, leave it to an Aussie to put 1k hp in a 14’ boat on a constricted waterway. What could possibly go wrong with that? Pretty sure it would be a hit down here too in the land of NASCAR..... :confused:

[svassh]

I haven't read the whole thread yet so maybe this has been suggested already. I do a couple HPDE events a year in my GT350R a car that FAR exceeds my driving abilities. However one of the best recommendations I ever got was Ross Bentley's book 'Speed Secrets'. Its an outstanding resource I recommend to everyone before their first HPDE event. The book covers many of the topics Jeff and JR posted on and does a great job of explaining castor, camber, weight transfer etc so it applies to autocross or any racing for that matter. The number one rule though already discussed is smooth is fast.

I browse thru this book the week before every driving event to refresh my memory.

[GTBradley]

JR, yeah I'll be checking the temps for real this Saturday at my third AX. My tire temps were above 100˚ after a long drive and they were consistent across the tire, I would think that if I had overinflated tires that the middle would be warmer and that's all I was looking for at this stage. I don't really expect to make any big changes from taking temperatures, but it's always good to understand a subject at a deeper level. Thanks for the insight.

svassh, I am headed out for a long road trip in SW Colorado soon so I took your advice on the book. I'll need something to read in the evenings. I found it at thrift books.com for less than 10 bucks. Thanks!

[J R Jones]

sva, I have had street and race Shelbys, and ran the later in Trans Am when they went to the GT specs. It is in CA these days.
Interesting that my old street car is now a vintage racer in TN.
jim149382149383149384

[johnpinetree]

Love love love the thread!

Bradley, I'm about to pull the trigger on transmission and rear end. Also plan to run a Coyote. Do you have any thoughts on how the TKO 0.64 and 3.55 combination worked out? Seems like staying in second was an issue, but maybe on just that one course?

[BEAR-AvHistory]

Yup, leave it to an Aussie to put 1k hp in a 14’ boat on a constricted waterway. What could possibly go wrong with that? Pretty sure it would be a hit down here too in the land of NASCAR..... :confused:

Who sponsored the event? I did some with THSCC, mostly very tight big box lot courses & difficult with manual steering. All second gear runs. Not active the past year or so. Expect to get back next summer.

[GTBradley]

That’s great, John and good to hear from you. I can’t say enough good things about this eng/trans/diff combo. I love this car and have zero regrets. The .64 OD is perfect for my long drives and you are correct the 1st gear versus 2nd is very course dependent and I’ve had both, but with the huge power band on the Coyote it can handle being used in the high ranges or low.

[NC Cobra]

Who sponsored the event? I did some with THSCC, mostly very tight big box lot courses & difficult with manual steering. All second gear runs. Not active the past year or so. Expect to get back next summer.

Kevin,
I’m running with the Central Carolina Region of SCCA here in CLT. Events are typically 1 per month, with the next being this coming Saturday, the 17th at the Z-Max dragway parking lot. Looks like about a 2 hour shot across I-85 if you are looking for something to do next weekend….
Cheers,
Jeff

[CraigS]

Johnpinetree, use one of the speed calculators where you input tire OD, eng rpm, trans ratio, diff ratio. Look for a 2nd gear good for 60-65mph. That will get you through 90% of AXs just fine. Shifting out of 2nd is almost always going to be slower either to 1st or 3rd. BTW the 1-2 shift is almost always dictated by making a smooth transition and not effing up a turn rather than going right to engine redline.

[johnpinetree]

Thanks CraigS,

Yeah I spent the better part of the day looking through these speed calculators. My other thought was that you probably don't want the rpm's to drop too low when you're in 2nd at 20 mph. Anyhow, this is what I'm thinking, be curious what your take is.

https://thefactoryfiveforum.com/attachment.php?attachmentid=150714&d=1626046999

For reference here is what the mustang GT runs at:

https://thefactoryfiveforum.com/attachment.php?attachmentid=150716&d=1626047169

I sort of figured that if I went any shorter on the final drive ratio I'd have a hell of a time getting grip with these light cars...?

[GTBradley]

Do you guys know if this would work for home mechanic alignments?

Longacre Racing Digital Caster/Camber Gauge (https://www.jegs.com/i/Longacre+Racing/441/78298/10002/-1?msclkid=e4b5049b02451e115690646b8d09e2bd&utm_source=bing&utm_medium=cpc&utm_campaign=BSC%20-%20Non-Brand%20Searches&utm_term=4579397212854022&utm_content=Other%20Categories)

[J R Jones]

Brad, Longacre has a long positive history supplying the racing market. I have used their pyrometers and scales.
Review feedback on Summit is positive.
My only concern is secure fastening to the wheel.
jim

[RoadRacer]

FWIW GTBradley, I got one of these (1 gauge+string frame) secondhand, and it does a good enough job and includes toe too.

https://www.wheelalignmenttools.com/product/4-wheel-alignment-system/

I imagine that longacre are better quality, but mine works for shadetree mechanics..

[CraigS]

Yes it will GT. Here is another option.
https://www.longacreracing.com/products.aspx?itemid=1798&prodid=7219&pagetitle=Caster-%2f-Camber-Gauge-%26-case-only---NO-ADAPTER
At this price you can buy two. Here is my mount. A piece of shelving so I didn't have to paint it.
https://live.staticflickr.com/1755/42572430562_42b43fcc4b.jpg (https://flic.kr/p/27RYQpu)Align tool (https://flic.kr/p/27RYQpu) by craig stuard (https://www.flickr.com/photos/152454123@N04/), on Flickr
I used the bungee because it was quick and, at the time I only had one gauge. Later I made up a J bolt and wing nut attachment that hooked to one of the spokes in the wheel. Covered the end w/ some rubber hose so it would not scratch the wheel. The gauge comes w/ a coarse threaded hole so I loctited the short stud in place. A couple of fender washers, nylon washers, and a nylock let me tighten it just right so it doesn't sag but will twist to center the end bubble.
https://live.staticflickr.com/1744/42623267491_6a10ef6046_z.jpg (https://flic.kr/p/27Wtosg)20180606_134740 (https://flic.kr/p/27Wtosg) by craig stuard (https://www.flickr.com/photos/152454123@N04/), on Flickr
The two aluminum pieces are velcroed in place and make it easier to eyeball the 20 degree steering turn needed whne measuring caster.

[CraigS]

Johnpinetree, that graph looks perfect. Getting 76 out of 2nd you will see that speed in very, very few autocrosses so you could probably go to a 373 but your comment about traction is correct. Nice thing about having just a slightly too tall 2nd is you never need to look at the tach.

[GTBradley]

I was planning to do exactly that, Craig, but the gauge is out of stock and I had found the Longacre at half price.

[Rdone585]

I used the Longacre gauge that attaches magnetically to the hub. I did have to remove the center plate on my wheels and fabricate one out of sheet metal. The original was aluminum and not flat, so the gauge wouldn't hold in the proper position. My centers came off easily with 3 screws, some just snap in place.

[GTBradley]

Well, the season is coming up and I'm looking at buying some spare wheels for autocross day and would like to know if any of you autocross guys can tell me if these are okay:

17x9 and 17x10.5 wheels 5x114.3mm/5x4.5" bolt pattern
The rears are 6.53 backspace +20mm offset
fronts are 6.02 backspace +26mm offset

That size works but the backspace and offset are a little different than what I currently have. Will these work?

161331


For reference, FFR advertises theirs as:

Front Wheel Size (Diameter x width): 17"x 9"
Rear Wheel Size (Diameter x width): 17"x 10.5"
Front Wheel Backspace: 6.00" (24mm Offset)
Rear Wheel Backspace: 6.7" (27mm
Offset Wheel Lug Pattern: Ford style 5 lug x 4.5" bolt circle

For tires I'm probably going to do the Nitto NT01

[Indy Shu]

Fronts nearly identical to FFR specs and rears would be moved inboard just over 1/4”. I think you’d be ok, but check inside the rears to make sure there’s room.

[Bob Cowan]

The rears should fit fine. You have room there to add a spacer if you need it.

The fronts will fit fine as well.

Have you considered a Hoosier A7 tire? I mean, as long as you're looking at a dedicated tire, must as well go big. Of course, once you experience the Purple Crack, it's tough to go back. ;)

[Jeff Kleiner]

I "think" you'll be OK with those. My fronts are 9" with 5.94" and 24MM. My rears are 10.5" with 6.81" and 27MM however that's on a straight axle, not IRS.

I've run a couple of sets of NT01s (255/40 front and 315/35 rear). Have them heat cycled when you purchase; they'll last longer and you won't have to scuff the mold release off the get them to grip. Start at 20 psi and go up or down 1-2 depending on what you need.

Good luck!

Jeff

[GTBradley]

Thanks, guys. It's always nice to be sure. I may end up needing spacers on the rears, as on the right side the tire is only a ¼" away from the coil-over with my FFRs. Does $500 sound fair for the 4 wheels?

[GTBradley]

Yeah, I looked at those A7s today, but dang they are pricy! You have a source better than $500 for the rears, Bob?

[Bob Cowan]

Yeah, I looked at those A7s today, but dang they are pricy! You have a source better than $500 for the rears, Bob?

yes, they are expensive. And even more expensive this year. But they are the best. A set this is going to cost me about $1,500 this year.

This is where I buy mine: https://trackdaytire.com/

[GTBradley]

You almost have me convinced, but I won’t be trailering, so I need something that’s also a streetable tire.

[CraigS]

$500 for the wheels is OK especially if buying from a person so no shipping or tax. But look here;
https://www.americanmuscle.com/buwh1-9404.html
https://www.americanmuscle.com/dedibuwh.html
Those links are a couple years old but I did do a refresh page. Double check that these are current prices. Also note the year Mustang that they fit and then search for other styles. AM has lots of them.
Depends how far you have to drive. I autocrossed my MkII for 15 yrs on Hoosiers driving to and from the event on them. Yeah that probably isn't the best for the tires
but I enjoyed driving back and forth and had no interest in a truck and trailer. The only problem is rain. I got caught once in a while and it is not fun having to stay under 40 mph but the tires are so phenomenal. OTOH, another option is run in CAM-S on BFGs, or one of the other 200 tread wear tires.

[GTBradley]

Thanks, Craig, those do look to be a good deal especially considering the free shipping and they would have only cost me 60 bucks more, but as it turns out the wheels I got are nearly new and I saved about $300 over their original price. I suppose I could have negotiated, but they were the only local wheels I could find that were the right size and I'm impatient to get the season started.

[GTBradley]

So I've got the wheels, now for the tires. Yes, yes I know, I've been told I shouldn't even be on sticky tires until I've got more experience, but I don't want to wear out my street tires and like I said, I'm impatient. I'm also tired of my Nitto 555g2s squealing all the way around the track.

In doing my research on what I wanted in a dedicated autocross tire I settled on the 100 tread wear category, even though I thought hard on how I could make the R-comp, Hosier work. The 100s are the stickiest AX tires that are also highway legal, barely.
The tires I considered were:
Nitto NT01, Toyo Proxes R888R, Hoosier A7, Nankang AR-1.

161679161680161681161682

Grassroots Motorsports has a really good article, done recently, on Ultimate Track Tires (https://grassrootsmotorsports.com/articles/track-tire-buyers-guide/). I used their matrix and suggestions for AX tires to select the Nankang AR-1. I didn't go with the best tire, the Hosier because you can't use them on the highway and I won't be trailering or using a support vehicle, as I'm still just planning on learning/having fun and not competing in AX for the foreseeable future. I didn't go with the Toyo R888Rs simply because they are not available right now. The Nitto 01 reportedly are not as quick to warm up as the Nankang though the Nankang AR-1 suffers from heat tolerance, but I won't be using them in a way that heat build up will be an issue. My thought is the tire that warms the quickest is best because AX runs are usually around 50 seconds long. Realistically, the Toyo, Nitto and Nankang would all work fine for me, but the Nankangs are interesting, so I'm going to try them.

The article suggested for autocross choose A or AA for Warm-up and B or better for Pace:

https://thefactoryfiveforum.com/attachment.php?attachmentid=161678&d=1643856723

[Jeff Kleiner]

I'll look forward to hearing what you think of the Nangkangs. I've eyed them but am not ready for tires right now (actually I could stand a set since the current ones are 2 years old and won't be optimal this year but it's hard to justify with <1,000 miles on them). I've run two sets of NT-01s and am currently using R888Rs so it's interesting to see that my observation that the Toyos warm up faster matches the tester's.

Jeff

[GTBradley]

This tire technology is very interesting to me. It's amazing what scientists and engineers can come up with just by reformulating the same ingredients. It does make me wonder if the Nankangs will be more popular in AX because of the gains they made in the warm-up category.

I can see not wanting to replace these every year as the cost was about $1300, however, I couldn't get free shipping and I paid to have them heat cycled.

These tires came with tech data and tire pressure suggestions that kind of surprised me too. Are you seeing those kind of temperatures on your tires?


Nankang AR-1Competition Tire
175/50R13, 185/60R13, 185/60R14, 195/50R15 - perfect for Vintage / Historic Racing!Also for Vintage we have the 205/60R13 and 235/45R13*** Nankang AR-1 Specs *** (https://philstireservice.com/wp-content/uploads/2019/06/Nankang-AR-1-Specs.pdf)

[*=center]Special inner angled pattern design to improve performance in wet track conditions.
[*=center]Special bevel pattern design for improved tire stiffness.
[*=center]Large block at tire shoulder for improved tire stiffness and traction on curved roads.
[*=center]Wide center ribs for improved steering performance and precision.
[*=center]Optimized tread with wider contact patch for the best stability at high speed driving.
[*=center]Unique semi-slick compound shorter tire warming time which speeds up tires in reaching effective working temperature and improves gripping performance.


Set up tech tipsOptimum operating window 160F degrees to 220F degreesOptimum camber settings between -1.0 to -3.0 degreesHOT Pressure settings - Just a guide - precise pressures should be decided by driving style, ambient temps and car set up23 - 27.5 psi for cars less than 1760 lbs 24 - 32 psi for cars 1760 lbs - 2200 lbs 27.5 - 37 psi for cars 2200 lbs - 3080 lbs34 - 42 psi for cars over 3080 lbs

PTS offers Tire Shaving (https://philstireservice.com/shop/tire-shaving/) starting at $40 per tireWe also offer Heat Cycling - Have your competition tires heat cycled today and be race ready!*Caution: The Nankang AR-1 is recommended for competition events only.

[CraigS]

I haven't run Nankangs so my A7 experience may not transfer but here it is anyway. Pressures 18-20. As low as 16 at the beginning and end of each season when weather is cooler. In addition to tire temps across the tread I use white shoe polish at the edge of the tread to see how far they are rolling over. Re-apply after each run. You want to see wear to the top of the small arrow.
https://live.staticflickr.com/7842/40548232833_f633fc277d.jpg (https://flic.kr/p/24M7hWD)Tire triangle (https://flic.kr/p/24M7hWD) by craig stuard (https://www.flickr.com/photos/152454123@N04/), on Flickr
Again these are different tires, but when it gets hot out 80F or more, you may need to spray the tires w/ water so they don't get too hot and greasy. Camber at -3.0 front and -2.0 rear.

[bionicbelly]

I have experience with quite a few of these tires. I'd skip the nankangs if I were you. They are not super durable, and not that quick either. Nitto's are ancient tech. They were great in the day, but there are WAY better tires out there. Toyo's are kind of the same. Both are ok for track days, but slow, and not good autocross tires.
If you want the straight up fastest, it is the Yokahammas, or RE-71R's. (if you can find them) The best all around and best wear are the Hankooks. You can do an entire 24 hour race on a single set. They are also grippy in a very wide heat range, which will work for autocross.
Another one to look at is Cooper RS3. Very fast, very good wear. They require completely different alignment specs that the other 200 tw tires though. They are MUCH stiffer, and will want much less camber, and less toe than the others.
https://www.jbracingtires.net/
This guy has lots of used race tires, if you want to try some stuff out before you buy new stuff. A7's, Toyo R1R's etc. (It's easiest to call him fyi)

[GTBradley]

Ah, “missed by that much!” Just ordered them last night. Thanks for the input, I knew it was a risk someone would say the Nankangs aren’t that good. I’ll let you know what my experience is and, by the way, I was aware of the durability and am willing to deal with that aspect.

[GTBradley]

I haven't run Nankangs so my A7 experience may not transfer but here it is anyway. Pressures 18-20. As low as 16 at the beginning and end of each season when weather is cooler. In addition to tire temps across the tread I use white shoe polish at the edge of the tread to see how far they are rolling over. Re-apply after each run. You want to see wear to the top of the small arrow.
Again these are different tires, but when it gets hot out 80F or more, you may need to spray the tires w/ water so they don't get too hot and greasy. Camber at -3.0 front and -2.0 rear.

Thanks, Craig, changing camber on track day is the thing I need to learn next.

[bionicbelly]

Ah, “missed by that much!” Just ordered them last night. Thanks for the input, I knew it was a risk someone would say the Nankangs aren’t that good. I’ll let you know what my experience is and, by the way, I was aware of the durability and am willing to deal with that aspect.

Honestly, you won't hate them. They are not a "bad" tire per say, there are just better ones, and I don't know how big of a deal the chunking will be at autocross temps. Might not be an issue at all for that.
The most important thing is to get out and drive and have some fun. On any tire.

[GTBradley]

**Reposted from build thread**
It's been a long, cold and dark winter off-season, but I stayed busy in the garage. My powder coating project was a success, as was my addition of the windscreen washers and intermittent wipers. But once those things were done I turned to autocross prep. I'm still not convinced I'll become a real competitor in the sport, but I do enjoy it. Especially, being outside and playing with the roadster.

So, you don't technically need anything other than a car and a helmet to do autocross, but I still wanted to improve my car's handling and have a set of tires that were dedicated to the activity - rather than prematurely wear out my all weather/summer tires. Here is a list of what I've done:

- Front Anti-sway bar (https://thefactoryfiveforum.com/showthread.php?30668-GTBradley-s-build-Getting-Setup-for-Autocross&p=487046&viewfull=1#post487046)
- Spare wheels and autocross tires (https://thefactoryfiveforum.com/showthread.php?30668-GTBradley-s-build-Getting-Setup-for-Autocross&p=487056&viewfull=1#post487056)
- Kirkey low back racing seat
- Power steering cooler and higher power steering boost valve
- PC'd FFR spare side pipes with sound suppressor installed (https://thefactoryfiveforum.com/showthread.php?30668-GTBradley-s-build-Getting-Setup-for-Autocross&p=487493&viewfull=1#post487493) (there are sound limits at SCCA AX events - 100 decibels at 50 feet for my events.)
- Removed the street bumpers front and back and installed quick jacks (I used the JK method (https://thefactoryfiveforum.com/showthread.php?16986-Rear-bumper-with-coupler-mod) so I can switch back easily)
- Vinyl roundel numbers and vintage decals
- I previously installed a throttle foot support to facilitate even throttle application. I also fixed an issue where the MAF tube with air cleaner would fall off.

https://thefactoryfiveforum.com/attachment.php?attachmentid=164420&d=1648060343 https://thefactoryfiveforum.com/attachment.php?attachmentid=164418&d=1648060199

https://thefactoryfiveforum.com/attachment.php?attachmentid=164415&d=1648060199 https://thefactoryfiveforum.com/attachment.php?attachmentid=164425&d=1648063423 https://thefactoryfiveforum.com/attachment.php?attachmentid=164466&d=1648099403

My main issues last season were traction, noise, sloppy throttle application, MAF/air cleaner falling off and sliding around in the seat. The other improvements are just nice to have and/or cosmetic.

[GTBradley]

So, for those that might know about SCCA rules (I'm thinking you, Jeff K) do Cobras typically break the limits for noise with their side pipes? Also, does a higher boost level in the power steering help in AX? I have my old valve that I plan to put back in the KRC PS pump.

[Jeff Kleiner]

My usual venues don't check sound. The only time I've ever been called out was a few years ago running on the road course at Lucas Oil Indianapolis Raceway Park which ironically is the home of the U.S. Nationals where the top fuel dragsters and funnycars blow about a bazillion dB! I think the big issue for us when trying to meet sound is that our pipes exit straight out the side---the sound monitors are set up perpendicular to the track's direction of travel so we blow right into the microphones. Some of the other cars that seem to be very loud like rotary engine Mazdas, fart can Hondas and even Coyote Mustangs exit out the back so I think the sound waves are dispersed before they are measured. If you find that you're repeatedly exceeding the limits turning the side pipe exits down might help.

As for steering assist, I run a Heidt's valve and adjust it down to back off the assist a bit on the street but turn it up for full boost when autocrossing or running on track. A few years ago I forgot to turn it up when I got to an auto-x but as soon as I got to the first gate and turned the wheel I knew and like Ralphie in Christmas story said "Ohhhh fudge (except I didn't say fudge" :)).

Cheers,
Jeff

[GTBradley]

Yeah, well Ralphie didn't say fudge either and you know what his mom made him do because of it...

I didn't realize adjustable PS valves (https://www.summitracing.com/parts/hdt-ps-101?seid=srese2&utm_source=bing&utm_medium=cpc&utm_campaign=Brands+%7C+H&utm_term=4581939832677723&utm_content=GSAPI+5ba2839995bcf) were a thing. I will look in to that but for now I'll install my other valve Friday night before the event.

[Logan]

I have the KRC power-steering setup on my Gen3 Coyote and it has replaceable valves, but I wish it were a variable adjustable style. I have to drain the reservoir and make a mess in order to change it currently. Went with the lower boost valve during the build, but would like to up the boost level slightly for this year (all I do with the car is autocross it since it's not registered or street legal yet).

I'm also looking forward to seeing how your off-season changes transform the car for this year! I know the front swaybar will help you throw the car into corners harder without being an oversteer-monster.

[CraigS]

GT I can't wait for your first report back w/ the upgrades. When you are trying to decide about the bar here are a couple of thoughts;
- remember it will be on the colder side so overall traction will be reduced
- expect that the handling balance may well be different in different parts of the course. If you are tight in turn X ask the other guys how there car is in turn X. Could be it is normal and not caused by your setup
- pure handling balance can only be found in a long duration turn. You have to get beyond the turn entry portion to the mid turn steady throttle portion which needs to last long enough to evaluate, before getting to the on the gas exit portion.
- when you walk, count the number of steps from one slalom cone to the next for the entire slalom. Usually around 30-35 for me. It's nice to know if the distances change especially if they get shorter. Equal distance slaloms are best done w/ steady throttle.
- some people like to go a little easy for the first run to 'learn the course'. My opinion is that would be nice if we have 8-10 runs but I can't throw a run away for that. All my runs are full hard.
- have a blast!!

[GTBradley]

I have the KRC power-steering setup on my Gen3 Coyote and it has replaceable valves, but I wish it were a variable adjustable style. I have to drain the reservoir and make a mess in order to change it currently. Went with the lower boost valve during the build, but would like to up the boost level slightly for this year (all I do with the car is autocross it since it's not registered or street legal yet).

I'm also looking forward to seeing how your off-season changes transform the car for this year! I know the front swaybar will help you throw the car into corners harder without being an oversteer-monster.
Me too, I really hope I don’t come back and say “meh, that was a waste of money”.
Regarding the KRC valve, I got it changed with very little fluid loss the last time. I didn’t take the cap off the reservoir so maybe vacuum helped. That variable valve Jeff mentioned looks easy enough to install in the KRC system, though the ports are different sizes and our lines are both the same size. I assume an adapter would deal with that. I assume too that, we would use the zero or lowest boost valve in a variable system.

[GTBradley]

Thanks, Craig. Yeah, my only concern for a hard first run is getting lost/DNF:o

I’m not planning for it this time, but my next outing will be a Test and Tune AX where I’d like to play with Camber. As you said before, -3 front and -2 rear. I haven’t gotten into this aspect, no tools purchased and no education on how to do it yet. But I’d like to ask, is there an easy way to do this at the track without alignment tools? Like, mark my current settings so I can go back to street settings then move nut x setting by x inches for -3 camber, etc. Don’t laugh too hard, just spit-balling here.

[Jeff Kleiner]

That variable valve Jeff mentioned looks easy enough to install in the KRC system, though the ports are different sizes and our lines are both the same size. I assume an adapter would deal with that. I assume too that, we would use the zero or lowest boost valve in a variable system.

No, the Heidt's valve doesn't have the ability to produce assist pressure so you'd want to use the highest boost valve in the pump and then adjust the Heidt's to bring it down to the level you desire.


...is there an easy way to do this at the track without alignment tools? Like, mark my current settings so I can go back to street settings then move nut x setting by x inches for -3 camber, etc. Don’t laugh too hard, just spit-balling here.

Conceivably yes, but not especially quick and easy. Realize that to make a change to caster or camber you have to adjust both upper control arm sleeves. Additionally, any change to those will affect toe so that would have to be adjusted as well.

Jeff

[J R Jones]

Brad, There was a time we did such things at SCCA Nationals, We would build an alternative part kit (control arm links in your case) and a hex flats count to do A-B-A tests, but that was with a team to do the work.
I suggest running with and without the ARB links is as much as you should explore at the track. Keep your head in the driving and evaluating mode.
Being detached from the wrenching also helps you stay objective. Taking post-lap notes (debrief) is beneficial. BTW do you have a data logger yet?
jim

[GTBradley]

Brad, There was a time we did such things at SCCA Nationals, We would build an alternative part kit (control arm links in your case) and a hex flats count to do A-B-A tests, but that was with a team to do the work.
I suggest running with and without the ARB links is as much as you should explore at the track. Keep your head in the driving and evaluating mode.
Being detached from the wrenching also helps you stay objective. Taking post-lap notes (debrief) is beneficial. BTW do you have a data logger yet?
jim
I don’t, but I’m looking at them now…

[CraigS]

I suppose you could change camber at the event but I wouldn't. As Jeff says, changing it will require changing toe in also so it gets complicated fast. I guess at a test and tune you could work it out since I assume you can run, make changes, and run again an hour or two later. You could adjust both UCA sleeves say 2 turns shorter and then reset toe. But the toe needs to be measured rather than adjusting it X turns. So you need a way to do that easily and accurately at the event. I use these and they would probably work for you since they are relatively small.
https://www.longacreracing.com/products.aspx?itemid=1709&prodid=10270&pagetitle=Toe-Plates-with-Magnets-(pair)
I just got the plates last year and prior I used my home built version of this.
https://www.longacreracing.com/products.aspx?itemid=1709&prodid=7212&pagetitle=Toe-Bar
I do agree w/ JR on the notes. A couple years ago I got a small 5x7 booklet where I keep notes. It has come in real handy. I make a quick list of current specs before the AX, note my comments while there, note any changes during the event, and note suggestions of what I might want to try next.

[GTBradley]

I’m going to give up on the camber idea for now and run the course as-is, make notes and get better at driving.

BTW, since I installed the Kirkey Low Back, 16” seat I really have noticed an improvement in visibility and driving confidence. I mounted it to the Breeze bracket and it sits slightly more upright, but the grip the seat has on you really lends a sense of authority over the machine. This might be the best money spent for AX.

[RoadRacer]

I use these and they would probably work for you since they are relatively small.
https://www.longacreracing.com/products.aspx?itemid=1709&prodid=10270&pagetitle=Toe-Plates-with-Magnets-(pair)
I just got the plates last year and prior I used my home built version of this.
https://www.longacreracing.com/products.aspx?itemid=1709&prodid=7212&pagetitle=Toe-Bar


Perfect timing. I checked toe last weekend with my string lines and it's such a pain to setup that I was going to look for better solutions. I was going to go with this one:

https://www.longacreracing.com/products.aspx?itemid=1709&prodid=7237&pagetitle=Toe-Gauge

A quick scribe on the tire, throw the tow gauge under.. seemed very quick and accurate. Am I missing something that makes the plates a better choice?

[J R Jones]

I like Craig's magnet/slot plates. Looks cost effective too.
With that or pointers, tread flex and stiction to pavement can reduce accuracy. Rather than spin-plates at the race track, we brought a stack of floor tiles and put two under each tire. The low-friction tiles reduced tread stiction and sidewall flex. The alternative is to roll the car fore and aft to let the adjusted tires relax.
We also stacked tiles under the tires to level the four corners for weight balancing.
jim

[CraigS]

Perfect timing. I checked toe last weekend with my string lines and it's such a pain to setup that I was going to look for better solutions. I was going to go with this one:

https://www.longacreracing.com/products.aspx?itemid=1709&prodid=7237&pagetitle=Toe-Gauge

A quick scribe on the tire, throw the tow gauge under.. seemed very quick and accurate. Am I missing something that makes the plates a better choice?

I have used a similar tool and it worked fine. The only problem I saw w/ it was some tire treads don't have a nice flat area right in the center. That can make it a little more difficult but no less accurate. I remember needing to roll the car a little to get a solid piece of rubber at the point of the tool but it isn't a deal breaker by any means.

[RoadRacer]

Thanks JR, Craig. Yes, I'm already in the habit of steering side to side and then rolling back and forth 3ft after every change. Even sometimes stand on it and jump up and down!

The alignments are making such small movements I don't want the tire having any effect.

[CraigS]

One other thought. As you get closer to your final sleeve length getting those last 1/4 degrees of camber and caster set, start at least snugging the jam nuts after you adjust the sleeve. I find that if I leave them completely loose, get my adjustment perfect, and then tighten them, they will lengthen the sleeve.

[GTBradley]

First, let me say it was a glorious day! Beautiful weather (sorry to rub it in Jeff), fantastic early morning drive - hour and 15 min drive down to Pikes Peak Int'l Raceway - a great course and some good racing!

https://thefactoryfiveforum.com/attachment.php?attachmentid=164724&d=1648519857

The Nankang AR-1 tires were an unbelievable improvement over my street tires on the track. The first thing you notice is all the sand that the tires pickup and throw in the wheel wells, and the traction is noticeable even on the street in normal driving. On the course it is amazing the additional centrifugal Gs they can withstand and the braking...well, it is hard to lock them up, though I was still able to and it made copious amounts of tire smoke when I did!

I did the white shoe polish at the the edge wear indicators, set my tire pressure to 23 psi and ran a shoe polish line across the width of the tires.

The first picture is after the first run and the second picture is after six runs and a drive home. The line drawn across widthwise was worn off completely after the first run on all tires. I took temps with my IR thermometer and the tires were progressively warmer going from inside edge to outside: 104°F to 112°F.

I'm very pleased with my tire choice and feel like I have a good starting point for improving my skills rather than listening to my street tires screech and squeal all afternoon. One negative I noticed while braking hard was the inside rear tire felt as though it was bucking after a very fast straight topping around 60mph and hard braking into sharp turn.

https://thefactoryfiveforum.com/attachment.php?attachmentid=164718&d=1648519346 https://thefactoryfiveforum.com/attachment.php?attachmentid=164715&d=1648519346

The seat was at least as good of an improvement as the tires were. I highly recommend it for autocross.

My times improved on each of the six runs and I placed smack in the middle of the 85 cars that were running that day and won my class, though there was only one other car in it. My class was XP but they had us put PM on the car for some reason. The best time of the day was 70.178 and mine was 76.717. This was the last AX of the winter series so there was some serious competition and not so many novices.

By my calculations, which I won't go into, I have improved over my previous AXs times by about 10%. That's encouragement enough to make me want get back out there and keep getting better. Plus the improvements to the car make it so much more enjoyable to drive and even somewhat more intoxicating. I really felt like I was doing something, if you know what I mean. Looking forward to the next one.

https://thefactoryfiveforum.com/attachment.php?attachmentid=164722&d=1648519648 I have got to get a smaller helmet!
https://thefactoryfiveforum.com/attachment.php?attachmentid=164719&d=1648519361 https://thefactoryfiveforum.com/attachment.php?attachmentid=164720&d=1648519361 https://thefactoryfiveforum.com/attachment.php?attachmentid=164785&d=1648653024

[john42]

Very nice! GTBradley what were the outside/weather temps like? I keep hovering over the "register" button for this weekend in MA/Devens, but the morning temps of 20F and high of 40F keeps making me shy away and wait another 2 weeks for a little warmer weather.

[CraigS]

"That's encouragement enough to make me want get back out there and keep getting better. Plus the improvements to the car make it so much more enjoyable to drive and even somewhat more intoxicating. I really felt like I was doing something, if you know what I mean. Looking forward to the next one."
A great report! AX is an addiction for sure. I am 73 and ran my first one when I was 19. There have been times where I got into other things but I keep coming back. My first AX this year is this weekend and it is a double, so AX on Sat and AX on Sun. A couple of weeks ago I told my wife about this schedule saying I will definitely run on Sat but Sun may be a question. She rolled her eyes and said, 'Yeah right, you might skip an AX, yeah right.'

[GTBradley]

Very nice! GTBradley what were the outside/weather temps like? I keep hovering over the "register" button for this weekend in MA/Devens, but the morning temps of 20F and high of 40F keeps making me shy away and wait another 2 weeks for a little warmer weather.
20! That's an easy decision, stay home and eat doughnuts and drink coffee. I wouldn't mind putting the top on for a long drive in cold weather to an AX event that was going to be in the 50s, but that's a tough one. Let us know what it's like if you do it. I started out at 47° but it got up to about 70°, so it was really nice.

[GTBradley]

"That's encouragement enough to make me want get back out there and keep getting better. Plus the improvements to the car make it so much more enjoyable to drive and even somewhat more intoxicating. I really felt like I was doing something, if you know what I mean. Looking forward to the next one."
A great report! AX is an addiction for sure. I am 73 and ran my first one when I was 19. There have been times where I got into other things but I keep coming back. My first AX this year is this weekend and it is a double, so AX on Sat and AX on Sun. A couple of weeks ago I told my wife about this schedule saying I will definitely run on Sat but Sun may be a question. She rolled her eyes and said, 'Yeah right, you might skip an AX, yeah right.'
Well, we benefit from all those years of experience and thanks for that. You are a tough guy doing two in a weekend, I might do it, but I know I am wiped out by the time I get home from just one day. It sure makes the doughnuts look better at home on Sunday.

https://thefactoryfiveforum.com/attachment.php?attachmentid=164751&d=1648567936

https://thefactoryfiveforum.com/attachment.php?attachmentid=164746&d=1648523989

[Avalanche325]

So, for those that might know about SCCA rules (I'm thinking you, Jeff K) do Cobras typically break the limits for noise with their side pipes? Also, does a higher boost level in the power steering help in AX? I have my old valve that I plan to put back in the KRC PS pump.

Noise restrictions are dependent on the venue. Also, these cars vary considerably on how loud they are.

For P/S I would find the feel that you like and leave it alone. You want muscle memory.

[GTBradley]

Actually, they didn't have sound testing like they said they would. My pipes are quieter now anyway, so I'm not going to work about it.

I didn't end up changing the PS valve and and never even thought about the steering, so I guess what I have is fine.

A question about Class designation for the FFR Roadsters. It is easiest to put the car in the XP class, but there is a large PAX time penalty for it too. I noticed that they have at least one other class for the Cobra:


From rule book (https://cdn.connectsites.net/user_files/scca/downloads/000/060/877/2022_Solo_Rulebook_wCovers.pdf?1647612527):
CAM S (Sports) (all eligible vehicles)
• Sports cars, sedans/coupes, trucks, and 1965-67 Cobra roadster
replica “kit cars” with seating for 2 or more adults.
• Interior floor covering may be removed.
• Weight without driver, minimum (lbs.):
• Corvette (1984-2019); Viper............................................. .......... 2900
• All other cars .................................................. .............................. 2500
• Additional weight for Lexan® front windshield (lbs.) ............................ +150

This would allow for much lower PAX time required to compete with the Mustangs, etc. Though, it would require some added weight. Has anyone done this?

Also, do they actually require you to add 150 pounds if you have a Lexan windscreen? Mine saved 30 pounds over glass not 150.

[john42]

I plan on running CAM S. Though I'm just getting back into it after a 15 year break. I'm also just in it for fun, so I don't really care too much about penalties.

[Jeff Kleiner]

Bradley, Yes, to be legal for CAM-S you would have to weigh a minimum of 2,650 which you won’t make unless your car is extremely porky (point of reference mine weighs 2,180 with a full tank). Even if you did make weight your 100 treadwear tires would kick you out. The class doesn’t allow anything less than 200.

Same for you John, if anyone protests you probably won’t make weight.

People have asked me why I don’t run CAM-S and my answer is that I don’t see any point in making the car heavier and going to a lesser tire just so I can run slower ;)

Jeff

[GTBradley]

I was thinking more for years down the road, Jeff. Right now, I’m fine with the raw times, it just seems strange to penalize us something like 4 seconds against the Mustangs. Now I really don’t understand the Lexan penalty, especially when there is a minimum weight. Thanks for the input though.

Side note, I have tragic news…my wife says I can’t go autocrossing on Mother’s Day :(

[CraigS]

People have asked me why I don’t run CAM-S and my answer is that I don’t see any point in making the car heavier and going to a lesser tire just so I can run slower ;)

Jeff

The other thing w/ Cam S is that the good 200 tires are only maybe $20 each less expensive than Hoosier A7s.

[john42]

Bradley, Yes, to be legal for CAM-S you would have to weigh a minimum of 2,650 which you won’t make unless your car is extremely porky (point of reference mine weighs 2,180 with a full tank). Even if you did make weight your 100 treadwear tires would kick you out. The class doesn’t allow anything less than 200.

Same for you John, if anyone protests you probably won’t make weight.

People have asked me why I don’t run CAM-S and my answer is that I don’t see any point in making the car heavier and going to a lesser tire just so I can run slower ;)

Jeff

Ahh.. didn't know that bit..

Ok. So.... I don't know much about XP.. That the full name of the class? Guess I need to google that. I'm (weather permitting) going to join my first SCCA next weekend so I need to pick.

[Jim1855]

Just curious. If you just want to run and all you care about are your raw times will the event staff let you? Do you just pick a class close to where you'd fit?
Jim

[GTBradley]

If you get the class wrong they will fix it for you. You don’t have to compete so much as have fun. I believe XP is the only other option for replica cobras as they call them. XP is kind of a catch all that just about anything will fit into.

It’s called Prepared Category
X Prepared (XP)

see page 220 in the rule book link in #187 above.
…FACTORY FIVE RACING Roadster & Challenge Car Type 65 Coupe
All with a minimum engine size of 4.5L normally aspirated or the equivalent forced induction engine size and weight…

[Jeff Kleiner]

If you get the class wrong they will fix it for you. You don’t have to compete so much as have fun. I believe XP is the only other option for replica cobras as they call them. XP is kind of a catch all that just about anything will fit into.

It’s called Prepared Category
X Prepared (XP)

see page 220 in the rule book link in #187 above.
…FACTORY FIVE RACING Roadster & Challenge Car Type 65 Coupe
All with a minimum engine size of 4.5L normally aspirated or the equivalent forced induction engine size and weight…

We can also run E-Modified, a class populated by Lotus 7 clones and one offs like Jeff Kiesel's monster Sprite

https://thefactoryfiveforum.com/attachment.php?attachmentid=164847&d=1648836146

Whether EM or XP a street driven Cobra replica is potentially a knife brought to a gunfight! Here is my sometimes competition:

https://thefactoryfiveforum.com/attachment.php?attachmentid=164848&d=1648836178

An RX8 with an LX sporting a massive turbo and enough wing to fly a small plane sitting on 14" wide slicks! Seriously, I can't play :)

But I can have a good time! And you should too!

I don't chase points or concern myself with PAX. Fast time on PAX is rarely a Prepared or Modified class car; FTD on PAX is usually taken by a lower Street class car like a Mini or Subaru with a good driver. I like to aggravate the guys who live and die by PAX by telling them fast time on the clock wins and if it takes a calculator to win they really didn't. It's kind of like saying that you beat Tiger Woods in a round of golf (after factoring your handicap ;))

https://thefactoryfiveforum.com/attachment.php?attachmentid=164858&d=1648836398

Craig and my late friend Wade Chamberlain (fastest man ever behind the wheel of a FFR roadster) had these shirts made up that sum it up pretty well! When I throw that out there it really gets some of the PAX boys wound up :D

https://thefactoryfiveforum.com/attachment.php?attachmentid=164850&d=1648836219

Go fast and have fun!

Jeff

164847
164848
164858
164850

[J R Jones]

The national championship racing of diverse motorcycles I have competed in was regulated by chassis dynos and weigh-ins after qualifying and the race. The formula to balance competition was based on power to weight.

jim

[GTBradley]

The national championship racing of diverse motorcycles I have competed in was regulated by chassis dynos and weigh-ins after qualifying and the race. The formula to balance competition was based on power to weight.
As a tangent issue, to irritate the investors of aerodynamics, we ran shorter tracks like Loudon NH without faring's and won. Aero drag, downforce and ram air were appropriate at long tracks with extended speeds beyond 100MPH. Aero at AX is like trash talk.
jim
That's what I was thinking, exactly! But, maybe they just leave them on from the long tracks they do. I would hope...

[Jeff Kleiner]

…Aero at AX is like trash talk.
jim

That statement is painting in kind of broad strokes. Formula SAE competitors and the papers written with their findings might disagree with it…

Jeff

[J R Jones]

That statement is painting in kind of broad strokes. Formula SAE competitors and the papers written with their findings might disagree with it…

Jeff

I have worked with, sponsored and hired Formula SAE competition students. Man powered, engine powered, solar and marine They do write papers, and they might disagree. Then they venture out into the world or teach.
With enough surface area and angle of attack/drag there is downforce to be had: I edited, you win.
jim

[RoadRacer]

I have to run in EM (E-Modified) because the hot rod isn't allowed anywhere else.. and yes "knife to a gunfight" so although I can't officially compete I just compare my raw times to those in CAM or AS (usually vettes) and aim at their times.

164916

[CraigS]

Roadracer has it. I wouldn't worry about classes. Just go w/ XP and have fun. People can go crazy, go broke, etc trying to pick a class to run in, and then pick a car to win that class. Then SCCA makes a change and BAM, you no longer have the horse for the course. People who run the national events and really, really try to win a class go to extremes. There is an AX out west somewhere that is basically a national runoff. It is a multi-day event. I have heard stories of guys showing up w/ three sets of mounted new tires. 1- the tire they currently think is the best, 2- the tire they think might be better (because there is enough time to do back to back testing), 3- a tire they feel is the best in the rain. This in addition to it being at least a 5 day deal so the need to cover the expense of living there for that amount of time in addition to towing time. As you do more events you will make acquaintances with other guys. Today I hung out a little here and there w/ a fast 2017 Mustang driver, a Corvette C6 ZO6 driver, a Fiat Abarth driver, a late model Camaro 1le driver, a Subaru driver, and a Porsche 911 driver. From about 2015 to 2019 I was good friends w/ a Lotus Exige driver. he was usually in a class by himself or w/ 1 or 2 others. We noticed that our times were usually close so he spent most of his time comparing to me. Don't get me wrong, I like to do well, but as long as each of my runs is faster than the previous, I go home satisfied. BTW, I never pay any attention to PAX.

[john42]

Ya I'm not out to win. I just want to reasonably compare my times with other cars.

[Matt Ries]

Tell me about the 'heel stop" from Breeze. Sounds like something that would help me. I looked at the Breeze site and couldn't find it. Finesse does not come to me easily. I'm kind of ham fisted throwing the car about. I know I could be faster if I was smoother :) but heck I have fun! Speaking of fun, ck out the Motor vault event on Motorsports Reg. Coming up at Putnam Park in Green castle (central) Indiana July 23&24th. Motorvault is a Backdraft dealer organizing the event open to all marques and specifically Cobras! Run groups for all skill levels! Mary and I did this last year and had a blast! Any questions please ask.

[RoadRacer]

Go to any favorite car parts site and look for something like this. I have one and they make a difference even on the street.

https://www.jegs.com/i/JOES-Racing-Products/514/25837/10002/-1

[GTBradley]

Tell me about the 'heel stop" from Breeze. Sounds like something that would help me. I looked at the Breeze site and couldn't find it. Finesse does not come to me easily. I'm kind of ham fisted throwing the car about. I know I could be faster if I was smoother :) but heck I have fun! Speaking of fun, ck out the Motor vault event on Motorsports Reg. Coming up at Putnam Park in Green castle (central) Indiana July 23&24th. Motorvault is a Backdraft dealer organizing the event open to all marques and specifically Cobras! Run groups for all skill levels! Mary and I did this last year and had a blast! Any questions please ask.

The Breeze part number was 70757 but it isn’t on his site anymore. You could call him and find out where he was getting them or go the Jegs route. It is worth it IMO and a help with street driving too.

That Motorvault event sounds like a lot of fun, I wish we could get a Cobras only AX event going here in CO.

[CraigS]

Matt, look carefully at your throttle. If it is cable think about going to a linkage. W/either one, look into slowing down the carb movement relative to pedal movement. At some point you will be steering with the throttle, and having it easily controlled is a game changer.

[GTBradley]

Nice video on tire pressure:


https://youtu.be/AjLx8vFlzLI

[Real Time]

Good for you.
Looks like a great time.
Hope you get to do lots more!