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can you post a before and after picture of one of the wheel wells with the wheel on? i'm thinking this is something that might be easier to to early in the build before the aluminum panels have been riveted in place and I could knock it out at the same time as the laundry list of other things to paint.
Bill,
I forgot to snap a before image prior to mounting the wheel. Hopefully you can reference the prior images to get a pretty good idea of the paneling without the wheel
http://i1369.photobucket.com/albums/...ps99d771a0.jpg
Rasmutaz I finally got to taking the front spacers off so here are some pictures as requested.
I have 5mm spacers in back to clear the trailing arms and no spacers up front.
I shot a couple in different lights hopefully they capture what your looking for.
Wheels:
Enkei Kojin
17x8 + 45 Front
18x8.5 + 45 Rear
Tires:
Hoosiers R6
225/40-17 Front
255/35-18 Rear
http://i1369.photobucket.com/albums/...psdb399e1f.jpg
http://i1369.photobucket.com/albums/...psfc5ab7c2.jpg
http://i1369.photobucket.com/albums/...psb32d3b0f.jpg
http://i1369.photobucket.com/albums/...ps468b94a4.jpg
http://i1369.photobucket.com/albums/...ps26f00471.jpg
In an effort to alleviate the front wheel rub I tightened the front springs to the point that only 7 threads remain visible and removed the front wheel spacers. I just went for a test drive and did everything I could to try and get the tires to rub. To my surprise the tire rubbing is gone and the nose diving is nearly non existent. The ride feels a bit firm but better than the alternative.
I am running and AutoX this weekend and going to race streets of willow next weekend so i'm curious to see if this all holds true when these tires get sticky and I start pushing the edge a bit.
Any idea what your current ride height is? How did you mount your front splitter?
front and back are both at 3 1/2"
I didn't do anything special for the front splitter. I slid it forward 2" and had to grind a bit off to do so. Light sanding, black silicon and 2 rows of 3/8 rivets. Same with the side valence.
I don't have pics mounting the front splitter but pretty much did the same thing as this.
Not sure if this was the best method but I am happy with it.
http://i1369.photobucket.com/albums/...ps51277e22.jpg
http://i1369.photobucket.com/albums/...ps0693a6fb.jpg
http://i1369.photobucket.com/albums/...ps3bf1478d.jpg
I made sure to leave the front area with clecos so i could slide the splash guards in between the CF and FG
Thanks Brando. Fronts looks so much better! With your 12mm spacers they were too wide for the body, making it look like you put a borrowed set of wheels from someone elses car and put 'em on yours. Tucked in just right, now.Quote:
Originally Posted by Brando
CSCC and SCCA hosted an autocross event practice today for tomorrows race. I raced all day today, 12 runs total. Since it was hosted at a Marine base there was quite a bit of room and they used it. I couldn't believe the size of this setup. 3rd and 4th gear for 80% of the lap.
My first run was a 70 second pass. Towards the end of the day I was consistently running under 60 seconds with my best lap time of 58.11. There were 2 guys who were the ones to beat, and I hear the same 2 guys are the fastest at most events. One guy in a race prepped vette the other in a GT3. Both running A6's.
Their best lap times were in the low 55's so for my first time out with my untuned 818 I was pretty happy to be a few seconds behind the fastest guys out there.
One thing I can say for sure is this car needs a spoiler to keep the tail in check. My tires compounded the issue. These tires gave no warning...you're on rails but the second you push a tiny bit too far you were backwards before you knew things were getting loose. Surprisingly I only lost it twice, but they were magnificent spins. The car spun so hard the front continued the slide all the way around for a lightning quick 360 which ended going straight with some momentum left. I actually prefer that because by the time everyone looks over your already straightened back out. I should be getting my spoiler in the next few weeks and then things will start getting interesting. Besides those 2 spins the car performed very well so long as I refrained from over driving it. It kept me on my toes.
I couldn't believe the difference in how fast other peoples A6's got sticky. My R6's were mildly warm after my runs, still hard and not ready to grip. These other guys with A6's were gripping after the first 1/4 of the track. I might have to invest in a set.
I could have surely picked up a couple seconds if I had more confidence and less oversteer. I also could have picked up a second with A6's. I'm confident I could have been contending for the fastest times with those 2 additions and a little more time behind the wheel.
At the end of the day I was given mad props by countless individuals for the times I did run and felt very accepted into this new group of gents. People give you automatic respect based on the fact you built the car and after turning some good lap times I found myself quickly adopted into several new groups. It was bromancing at its finest.
All in all, this first day at AutoX was epic however I think I need to print up some type of article describing what the car is because i grew tired of explaining it to people. I can think of worse problems to have.
Brando, the A6's are worth more than 2 seconds over the R's. What was you alignment settings?Quote:
Originally Posted by Brando
That's another problem. The alignment I had professionally done had way to much toe in. I don't have exact alignment specs because in the end I went of trial and error. I know my camber is 1.5 front and rear but was thinking of going 3 degrees up front and 2 in the rear. I couldn't tell you where my toe in is at the moment
I am open to suggestions Wayne
Brando,
Every spin for me auto crossing is only a 180. Did your spins happen because to much gas exiting a turn?
I can't remember, are you running LSD?
What tire pressures?
Bob
Sounds like a blast. I cant wait. When I start to test mine on the track, I'll shoot you a PM and maybe we can have a 818R day (Buttonwillow).
Like Wayne said, the A6 is 2 seconds faster. They warm up super fast. I have used them on my Porsche racer (close to 818R weight) for a 45min race to gain an advantage. I would only get about 6 (avg 30 min races) heatcycles out of them before they were toast. (Compared to 13-14 with R6's). I only used one set of A6's once because of their limited life span.
My starting tire pressures for road racing on the R6 (not autocrossing which is totally different), are around 26-28 depending on outside temp. This again is with a car similar to the weight of the 818R. Do not go by the Hoosier "Recommended pressures", go by what you feel after tires are warmed up. My light car liked the pressures around 32-34 hot.
With Hoosiers, you want at least 3 to 2.5 degrees negative camber. Some guys run more, but it really depends on the car. As far as toe, Wayne may have a better idea since he races the Lotus cars.
Keep in mind running R6's at -3 degrees, on the street or around town, you will could be wasting alot of "Hoosier" $ getting groceries :) . I see a second set of wheels/tires in your future. Haha
Brandon- Did you remove the front splitter before racing it? The snap oversteer is exaggerated buy having front downforce and not the rear wing on as we discussed in a PM.
I was hoping that by the time i grenade this trans FFR will support the 6 speed. With that in mind I decided one of the financial corners to cut was an LSD. So no LSD on this build. :(
I should have followed your advice Chad but ran short on time and didn't get the car back off the ground so I ran with the front splitter. But today the front splitter found balance.
It's my 39th birthday today, I wonder if FFR timed this delivery for today on purpose. This spoiler looks so beautiful in person. I'm dropping the car off in the morning for some fab work to get this thing mounted to the frame. I'm still at a loss as to how i'm going to do this and have it easily removable, aesthetically pleasing with adequate integrity. Hopefully these guys have some good ideas.
http://i1369.photobucket.com/albums/...psd4d6af9b.jpg
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I hope this duct tape holds up during racing
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I just got a set of new Hoosier a-7, for my Mustang, supposed to grip like an a-6 without the drop-off and wear. I haven't had a chance to use them yet. I can still run a couple more events on the Hankooks. I haven't made a decision on the 818. I think I am going to end up with more than one set of wheels and tires.
Did you purchase them with AutoX or Track racing in mind?
They are for auto X, they get very greasy when they get hot. That's why I figure I am going to have more than one set. The r-6 is very good but at a higher temp and the wear is much better. I have been using the Hankook Ventus for both. they are a bit harder to warm up than the a-6 and wear more than the r-6 but are 30% cheaper. So far I have not corded a set but they do cycle out and loose their grip.
I can't find the thread/post that deals with the optimal AOA for the GT-300. IIRC it was understeering at 5AOA.
Here are the # of downforce for the GT-300
0AOA:
80mph - 151lb
100mph - 238lb
120mph - 345lb
5AOA
80mph - 184lb
100mph - 290lb
120mph - 420lb
10AOA
80mph - 202lb
100mph - 317lb
120mph - 459lb
I'm curious at what point the spoiler will start making a difference. On a car this light perhaps at 100lb the handling will start changing?
I'm down for trial and error with this setup but out of the blocks I want to be as close to optimal as possible. Has anyone determined the best AOA for this wing?
Sounds like we will be needing the splitter and canards. Front is pretty light already.
I was looking at a set of APR canards. I just cutout their online template to determine which set will work best. I'm not sure if this is the best option. Do you have any recommendations?
I may not be the best person to answer that at this point in my build. That is one aspect that is way out there for me. Likely the last item I will decide on and deal with. I have a few bookmarks for wings...
In my 818R notes (per Wayne's posts) it says to start at 0 or 1 AOA. You really do not need to worry about canards yet IMHO. Just utilize the front splitter and rear wing together.
And you are right. 100 lbs of downforce on this light car will make a difference. Its easy to forget that without a wing the car produces "Lift" at speed. On my 911 without a rear wing, it produces almost 300 pounds of lift @ almost 150mph.... just by adding a small ducktail spoiler, it cuts the lift at the rear in half at that speed.
http://forums.pelicanparts.com/uploa...1109675532.jpg
Granted the shapes of the cars are very different, but we are adding a "real" rear wing to the 818R.
So 200 pounds may not "seem" like alot, but in reality it really is. Especially, the lighter the car. That is over 10% of the total weight of the car on the rear only. That does not take into account what is happening up front with the front splitter.
Wayne et all tested the 818R with just the rear wing and front splitter. They got a good baseline. I plan on sticking with that. In the most recent blue 818R photos/videos where John is speeding around like a madman, he is doing it with the stuff we already have.
I'm sure Wayne will chime in also- He has way more experience than me with aerodynamics on cars.
Sorry- I just drank a Redbull and started babbling on.....
Drink more redbull. I am starving for insight on the subject.
I notice the blue car's splitter is like 2" or less off the ground. Perhaps it was braking in the picture. My splitter seems like it angles up as it heads to the nose. I will take a profile picture of it, but I am worried it's actually creating lift not downforce.
The car is light and it will take more to get the tires hot, we had this problem with the challenge cars, we had to go to a smaller tire to get heat to them. If you have never driven a Challenge car this may explain the feelings you are having, the 818 is also on a short wheelbase (longer than the Challenge) but still somewhat short and you have to get use to if you are tail breakingQuote:
Originally Posted by Brando
On the third day of testing we backed off the rear wing angle to near 0 AOA and had a slight high speed aero push and neutral at 70 mph on the 818R. On the 818S with just the street splitter, it was loose no matter what we did with the front and rear springs. The wind tunnel backed up the track testing that it was aero loose since the splitter was doing a great job planting the nose. I put a GoPro in the nose of the S looking out over the splitter and it was being deflected down over an inch before we put and center brace in.
That's a BIG wing for street use. Wider than the car, no?
I really REALLY like your rims. I'll definitely have to check those out.
It sits almost flush with the outer most point of the fender flair. Yes it's huge for street use but works great for hanging your wet towels to dry. Perhaps that question was directed for Wayne, my focus is TT and perhaps door to door if I get to that point. I purchased these rims after seeing Jerome's setup, they do look very good on the 818 just stay away from curbs when parking.
Thanks Wayne that was helpful. Running only the front splitter I was loose at any speed. Neutral at 70 sounds perfect and pushing at high speeds is calming as well now that I'm a daddy.
If i set the wing to the lowest AOA it still has a few degrees in it so 0AOA doesn't appear to be an option for me. I get the car back today and will shoot some images of the mounting
You surf, Brandon? My boss surfs before work almost everyday and hangs his wetsuit over the tailgate on his truck... it's be perfect for that (not that I'd recommend salt water drying on carbon fiber!)Quote:
Originally Posted by Brando
I'll just put Brando on the back of my 818... he's gotta be around 235lbs :D
That's an impressive guess
230lbs
Jeff was still counting the extra "Baby Weight" :)Quote:
Originally Posted by Brando
Can't wait to see the mounting. I just ordered $100 of misc weldable brackets. I know I will make something work. Strong, removable, and ingenious..... That's what I'm going for, however the last one probably won't happen.
I'm pressed for time to get diffuser and a few other things installed before the night is over. On that note I will let the pictures do the talking.
http://i1369.photobucket.com/albums/...psc4826948.jpg
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Thanks for all the pics. Nice to see an R nearing completion.
Why the license plate bracket? Don't understand the O2 sensor after the muffler and why is there a muffler?
I think the hoop looks like a good design. Lots could be hung from it.
I have a straight pipe as well. This car will be street legal with plates for the occasional drive. The wide band o2 can go I just need a plug.
Very nice job, Brando; execution, design, all terrific.
Great design! That's almost worth towing down and having that done.
That is seriously beefy. :eek:
Are you going to bolt or pin the wing on? When do you go through the next phase of registration. I am interested how that turns out. I had figured with the windshield it would not be licensed.
Thank you. I am really pleased with how the design came out. These guys specialize in building off road chassis. Jerry at http://www.penhallfab.com/ was super nice and helpful.
I'm sticking with the pins, they will support the load and I like the quick release. I should be setting an appointment for the Refs which is the last step of the registration process. It is my understanding the windshield will suffice but it will need some sort of windshield wipers, even manual ones will work. I was considering the old Mercedes headlight wipers! Comical, it will work and it's a backhand to the refs.
I purchased a digital level to adjust my AOA. Now that I have a digital level I double checked the camber. Turns out 3 tires were exactly 0 degrees and my back right was +1!! Both my spins were on a left turn...makes sense.
I'm rather perturbed the alignment shop did nothing I asked them to. The camber opened up a can of worms. The rear was simple and took all of 10 minutes, both are at -2 degrees now. The fronts however were not going to change without grinding some of the theads on the UCA down. Both sides of the UCA were bottomed out and touching one another inside the adjustment bolt (whatever its called). I still have to button the UCA's up but I have them at -3 degrees now, what a PITA I wish I had done that from the get go.
I found a screw embedded in my tire, I took it out and have a flat now. So i have to get my Uhaul, patch a tire, complete the UCA's, tighten springs, get this think on the trailer, mount tires and re-install larger spacers in rear and be on the road tonight for a 3hr drive to Willow Springs. Looks like I might have to cut out of work a bit early. Reason for the spacers is 1/4" wasn't enough space from the trailing arms to the inside of the tire, there was a buildup of rubber on the arm and the inside of the tires were glazed from rubbing.
This will be a great 2nd round racing. AutoX round one, now a proper track round 2. This will compliment my R6 tire choice, my camber change should be HUGE, I have a rear spoiler and rear diffuser installed. I'm really anticipating the change in characteristics.
I got a gopro 3+ back edition and roll bar mount for my birthday so I will capture some footage of the track.
On a lighter note, last night was Rocki's first time eating solid food. This kid likes to eat! A new milestone acheived.
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Hey Brando, any pic or brand of your digital level?