Classing the 818 in NASA

[D K]

Hello

Ive seen the blue R classed in STR3 but after adding up all the adjustment points, I came up with 10:1 ratio meaning that max whp is ~200?

Is that right?

David

[Santiago]

There are a couple of factors that would play into this, but I think you're close. I'm guessing they may have had ballast in the car at that time to get to 2,060 lbs with driver. They may have also had different size tires at the time, etc. Bottom line is that the current blue R that has been burning up the track is so-not-STR3 legal, just way too much power in it now.

At any rate, I came up with a variety of classing scenarios that yielded some more favorable ratios, anywhere from 8.8 to 9.95, depending on what tires (slicks or street R-comp), tire size, comp. weight, etc. To stay legal for 3 you may be able to get away with low 200's, by my calcs. figure 235 whp is the absolute max with the right combination. [Whether that is the best combo for the car is another story.]

The upshot to all that is that you have STR3 legal power pretty much right out of the OEM box with the right engine selection. You're not stressing your engine to make power, which typically favors a reliable set up. I think the car should be decently competitive in STR3, but you're going to have to make the most out of the freedom in the STR rules. You certainly aren't going to power your way to a podium finish. Then again, none of the STR3 cars should be able to power their way to an advantage - that's the point of the class.

Best,
-j

[D K]

STR1 here I come

[Santiago]

STR1 here I come

I hear ya.

I'm thinking of going to STR3 at first. I figure that way I can build it w/o monkeying with the engine (read: not putting more money into it), it should be viciously reliable, and it gives me a year or two to learn how to drive the car and optimize the set up before relying on more power to go faster. Then we'll see how much sense it makes (for me) to invest in more power and jumping classes.

To be honest, I really wish they'd open up the STR2 class. I know it doesn't make much sense right now given the folks out there likely to compete, but it would make for a better fit for the power this car will likely have (I think I'm looking at actually de-tuning the engine to be STR3 legal). Then again, they should re-write STR2 for something more like a 7:1 ratio; that's what I'd like to see.

Best,
-j

[D K]

Just to make sure I got this right....

I added .4 for 275 dot tires and subtracted .6 for the weight of 2000lbs. That puts me at 5.3 and 8.8 - is that correct?

This allows for 227 whp or thereabouts for str3. Again, is this correct?

I'm curious what sort of power levels the guys on the east coast run?

d

[Santiago]

The way the rules are stated makes "subtract" and "add" a little odd when stated casually. You're actually subtracting 0.4 from the original 9.0:1, but then adding 0.6 for the 2K weight. The way I think of it is "you get a bonus for trying to compete on a smaller tire than most" (so you get to lower your required weight-to-power ratio), and "you get penalized for being in such a light car" (so you have to raise your required weight-to-power ratio).

With the 275 dot tire and 2,000 lb weight, you should get a 9.20:1 ratio, which should come in around 217 whp.
I'm not sure the car will fit a 275 tire in the rear, so you're probably looking at a 255 dot tire, which would still take the same modifier points (anything over 245 to 275). To get 8.8:1, you'd need to run the smaller 245 dot tire, which subtracts 0.8 from the original. Then I also get the same 227 whp figure you got for remaining STR3 legal.

I had said previously that they may have run ballast in the car, because at 2,060 lbs (a hair over the 2,050 cut off point) you get a marginally smaller modifier to add on to your required weight-to-power ratio (0.55 instead of 0.60). That'll generate 8.75:1, which comes to 235 whp (for a 2,060 lb competition weight).

Not sure if it's worth it. Hard to say without knowing what weight the R cars are coming in at, and the variability across builds is likely to be high given the differences in engine selection and a host of other parts that folks will look at to try to reduce weight. If you're ok with eating the 0.6 factor, you're allowed to be as low as 1,951 lbs, but that's likely a tough target to hit in this car (figure most drivers fully suited up are coming in around 180-200 lbs). You'd have to build the car to around 1,770 lbs wet to maximize that rule. If an R-car is coming in around the same as the factory white car (what was that? 1,820 lbs with 5 gals of fuel?), then the 180 lb driver sits in it flush at 2,000 lbs...that's with 5 gals in the tank...come in off the track on fumes and hit the scales, you may be close to 1,951 lbs. If you're a 200 lb driver who doesn't want to end his stint on fumes, you're down to 40 lbs shy of the more relaxed penalty-modifier. Not sure if that's such a huge price to pay, I dunno. Properly placed it might actually benefit the car, depending on its set up (...or, the benefit is a sign of a jacked-up set up!).

ARGHH! I want my kit, I want it built, and I want to be testing this thing already... =)

Best,
-j

[Grintch]

The STR weight rules go nuts at 1850 lbs (-2.7 vs ST at -0.7), so even if a super light configuration is feasible, the rules handicap would be huge.

I would also like to see a change in the ST2/STR2 power to weight factor. Going from 9 to 8 to 5.5 doesn't make sense to me. It should be halfway between ST3/STR3 and ST1/STR3 like 7 to 7.5 instead of being so close to the ST3/STR3 factor. That also looks like the sweet spot for a lightly modfied STI, or moderately modified WRX (~300 whp) engined car.

I expect that the 818 will be allowed in ST with some sort of adjustment like most of the other FFR cars eventually.

[D K]

What is keeping it from the ST class now?

[Santiago]

My guess is that the 818R is just too new to be placed in ST now. The basic ST classes are defined specifically for cars with an OEM chassis. They permit pretty robust cage additions & tie-in modifications, but they specifically rule out tube chassis cars or tube chassis conversions (STR is the class group that specifically permits tube chassis cars). If I recall correctly, there are a handful of tube chassis cars that are allowed, but these are petitioned and evaluated by NASA's officials on an individual basis.

I think Grintch is right, in a year or two it may be allowed in, but they're going to have to see just what these can do before assessing any sort of adjustment points or other restrictions on it. As an offhand thought, I'm sure that the fact that the FFR Challenge car is a pretty well known commodity (insofar as it's a spec car) helped it get admission into the ST classes. Without something similar for the 818R, there's tremendous variety in how one could build it, and that may make folks worry about how evaluate it's fit it into the ST classes.

Best,
-j

[Bill Waters]

Am interested to hear the response to DK's question. Also, my goal for my 818R is 350 rwhp and, in addition to TT/time attack events, I'll be seeking a class to run in. I would think that the higher HP 818Rs would be ideal for NASA's Super Unlimited class. Has anyone investigated this?

Thanks, Bill

[D K]

At 350, you may or may not squeak by in STR1 - depending on your weight and other mods.

In Super Unlimited, the only thing left to investigate is how likely you are to get a credit limit increase on your visa..

[Santiago]

At 350, you may or may not squeak by in STR1 - depending on your weight and other mods.

In Super Unlimited, the only thing left to investigate is how likely you are to get a credit limit increase on your visa..

:D

Yeah, one wonders where to place the emphasis here..."Super [build budget]" or "Unlimited [credit limit]". Then again, this is only if you're very serious about competing (i.e. you really do want to take top spot on the podium). I don't think a 350 whp 818R would get slaughtered, but I doubt it would be at the front of the SU class. But hey, I'd sure like to see that disproven. Now a purpose-built SU 818R (with far more than 350 whp)...that might raise some eyebrows. :cool:

Anyway, by my calculations you're going to have to fatten her up to make 350 whp legal in STR1...if you run slicks (as the Blue 818R test mule has been doing of late). If you can make DOT tires work well (read: you can win with them), then running 350 whp legally in STR1 should be cake (you may be able to get away with more than 370 whp).

I may try that route in STR3 (since the first year will be an experimental feeling-out year anyway, and obviously this would be with less power). Personally, I think Hoosier A6 tires should be interesting for this car. But if you're just always back-of-the-pack with DOT tires and thereby forced to run slicks, I think you're going to max out around 340 whp with the right choice of tire size/weight.

Best,
-j

[D K]

A3??????

Why 'A'?


Why x'3'?




How about R6?

[Santiago]

Oops! Man! What was I thinking? :confused:

Sorry about that. I meant Hoosier A6 (I fixed it in the previous post).

The R6 is a great tire and I love me some "purple crack" on the Mustang. The A6 is the their autocross DOT tire. You get more grip than the R6, but the downside is that you get even less longevity out of them. Still, folks report regular gains of a couple seconds over the R6 tires.

The A6's require less heat before delivering maximum grip. That's great for autocross where you're on the hammer with tires still at ambient temps. However, they don't seem to hold up terribly well to sustained heat. From what I've heard, (particularly in heavier cars) they can get overheated on a road course and get greasy after just a couple of laps. I do know of at least one guy who runs them on his Mustang (road courses), but I haven't really gotten detailed feedback beyond "they're fast."

Anyway, that Mustang guy was an anomaly. I've heard more frequently that lightweight cars are having much more success running the A6 for extended periods on road courses. So my hope was that they'd work pretty well on the 818R.

Best,
-j

[johngeorge]

If: Tire size 245 or smaller if DOT approved, add 0.8
2050-1951 lbs subtract 0.6
Net gain +.2

2000lb car at 8.8 yields 227hp max, then add .2 and you get str3's 9:1 limit

[blueafro]

I don't think a 350 whp 818R would get slaughtered, but I doubt it would be at the front of the SU class. But hey, I'd sure like to see that disproven. Now a purpose-built SU 818R (with far more than 350 whp)...that might raise some eyebrows. :cool:

I admit I'm a bit of a pessimist at times, but I would expect a 350 whp 818R to be slaughtered in SU. Perhaps not at every race, but certainly at any which the front-running championship teams attend.

In SU, the 818 would be up against retired Daytona Prototypes, RCR's LMP Cadillac clone, and sub 1,000 lb.former DSRs run by people who decided DSR was too slow* so went to NASA with boost and bigger engines. If an 818-based car were to have a prayer, it would not be in a form you'd much recognize as an 818 and certainly not at a price you'd recognize.

This is not a bad thing. The 818 is going to be a potent car for the money, and there's no reason at all to be unhappy with it if it can't run with cars up to ten times its price - or perhaps more.

* Of note is that an SCCA-legal DSR has lapped Elkhart Lake 1 second behind the time Mark Donohue ran in the 917/30. Yeah, tires and aero have come a long, long way since the early 70s, but still, I was stunned when I learned that. Can you image the potential cars like that have when they move to unlimited racing?

I'd certainly like to see what FFR could come up with in the unlimited space. Perhaps they could take the fight to RCR and the SCCA and IMSA refugues at a much lower price point. I still doubt you'll be taking many SU trophies home if you don't have well north of $100k in your car, and multiples of that in your whole program.

[D K]

Yeah, tires and aero have come a long, long way since the early 70s, but still, I was stunned when I learned that.


I believe the year was 1973 when a certain GoodYear engineer went on record as saying it was physically impossible to achieve more than 1.0G lateral cornering force.

Tires and aero have been the single most contributing factors to laptime in the last 20-30 years.

A 350whp 818 will get slaughtered in SU. Ive raced against those guys and have an idea what it would take to beat them.
You need a 1:20 at big willow to be competitive.

Im wondering where the 818 would stack up against a Radical? There are guys putting the EJ in those as well.

I think a lot is going to depend on how well the chassis does and how it likes big power.
Full aero, a better wing and wide slicks.

[Bill Waters]

Well, 350 rwhp is only my current goal..........

Thanks for the comments. I really do need to be building it with a class in mind

Bill

[blueafro]

Tires and aero have been the single most contributing factors to laptime in the last 20-30 years.

True, as acknowledged, yet the 917/30 was such a beast that its times on 1970s rubber remain fast on many a power track, and any car that gets close to those times is a formidible machine. To put it in some different perspective, that SCCA DSR lap record, set in 2012, was two seconds faster than the lap record for Daytona Protos, which was set the previous year.


Im wondering where the 818 would stack up against a Radical? There are guys putting the EJ in those as well.

That's intriguing. Any idea of the weight after the swap? The Radical proved a little too big for CSR/SDR in the States, but perhaps with a substantial upgrade in power they could find a home in another class, or at least be a stonking trackday car.

[C.Plavan]

sub'd

[Grintch]

What is keeping it from the ST class now?
Tube frame, non production car.

Another problem with SU is very small fields. Like 1 or 2 INCLUDING you a lot of the time. Which means you are not eligible for contingency money/parts/tires.

[D K]

Tube frame, non production car.

Another problem with SU is very small fields. Like 1 or 2 INCLUDING you a lot of the time. Which means you are not eligible for contingency money/parts/tires.



That's the EXACT reason why I'm not interested in SU

[C.Plavan]

I'm building my 818R to eventually compete in the NASA WERC series. I think it will hang in fine with the SU cars I have seen.

[Bill Waters]

OK, so what class would a 350 rwhp 818R be able to compete in? Part of my problem is that I keep evolving my plans. I am strongly considering an engine build based on a Cosworth STI short Block with 2.5 l heads with stage 1 cams and appropriate valve springs, etc.

Anyway, even though I will eventually be able to find an autocross class and can run Time Attack races, it would be a mistake for me to build this car and have no club racing class in which I can run. What classes given incremental hp values (400 , 450, 500hp)?

Thanks,

Bill

[D K]

Are you talking wheel to wheel?

If so, NASA has power to weight requirements which is why I started this thread.

SCCA as well which Im reading about now.

Anything over around 250whp and you are out of str3 and in str1.
Anything over around 350whp and you are in unlimited.

These numbers are estimates, depending on your weight.

D

[Santiago]

There's a couple of subtleties here to consider as we bench race. First, if we're talking about absolute performance comparisons you're usually inadvertently talking about the pool of cars/competitors at a national level. In this context, I'd concur that a 350 whp 818R would be thoroughly outmatched in SU. That said, there are probably regional competitions in which you may make the podium - all the more assured if the field is you and two other competitors. =) But in all fairness, not every region has the same mixture of track-types. You would think that a lower-hp 818R would do better on short/tighter tracks where they don't get beat up on by the uber-power of some of the SU builds. So in the right region, the 818R might have more of a fighting chance than others.

I suspect the 818R's real competitiveness (at least on the bigger/faster tracks) is going to lie in its aero development. Currently we're seeing pretty decent numbers out of the Blue-R, but honestly I think it has a relatively conservative aero package. The front splitter is small by race standards, the GTC-300 wing is nice but there are beastlier ones available, the rear diffuser from the looks of it is matched to the front splitter, and the bottom is only flat (nice, but not as effective as tunneled). All told, it's a very solid start, but also compelling enough to make me think the car has lots of room to grow with a more aggressive package. Making such a set up work for this/that track...yeah, another story.

D K pretty much nailed the current NASA classing possibilities for any sort of incremental hp builds. Until they fix [my words] STR2 and/or admit the 818R into The ST class ranks, you're basically looking at two standing classes. However...

About those small fields, at least one region (NASA-Midwest) has introduced a popular wheel to wheel format that mitigates much of the concern of small classes. They call them "Matrix Races," but they're basically the equivalent of the drag-racer's bracket racing. So you pick a standard class (say STR3), build to suit, go qualify for that race, go race, win, laugh, cry, make up stories. This is where things get interesting. You sign up for the Matrix race. Your qualifying time for your standard "build-class" works double-duty to situate you in a bracket class (defined on that day). They group you with cars running very similar times and (all-together now) create "a matrix" of classes that include all sorts of cars. You can be an uber-slow SU car racing against cars in AI, GTS1, FFR, or a ridiculously fast spec 944. There are no rules for power to weight, aero, and so on, since all cars are classed according to their posted times on that day. Like bracket-racing, if you're sandbagging during qualifying (side-note: why you would do that to the detriment of your build-class is beyond me), you can and will get disqualified for breaking out of your class if you post a lap time during the matrix race that is below the one set as the minimum floor for your group.

The format has proven to be hugely popular this past year. Indeed, we're now looking at even getting contingency sponsorship for it in 2014. Guys get to go toe-to-toe with cars they'd never see out on track, and since it's all based purely on times the racing is very-very close. This all started out sort of on a whim, matrix races were offered as purely for-fun events, but the response has been tremendous - it's just too much fun. If the other regions aren't doing this already, I'll bet they're going to catch on very soon.

The point of all that is to say, at least for me, some of the worry over picking a class to build to at the start has been alleviated. I know I can still get the car out on track with good sized fields regardless of which class I'm in. Matrix = Win/Win.

Best,
-j

[D K]

My only question is how the Matrix classes would work in a prize/coningency situation?

One advantage of a turbo engine is that you can have varying tunes.
So it is feasible to have a de tuned car in str3, then crank up the boost, run E85/98 and you are now in str1.
Or do the same thing with str1/SU.

Its possible....
We'll have to see where the rabbit hole leads

[Santiago]

That's a good question! I'm not entirely sure.

My guess is that they'll either set up single-event prizes or figure out a way to define the Matrix classes with enough consistency to earn points over a season. We'll see what they come up with. I don't think they're planning any "Matrix championships" so earning points may be a moot point anyway.

The flexibility of the turbo is a sweet deal, and I've seen guys really enjoy that multiple-class capability of their turbo cars. But I have a feeling I'm going to be putting my tuner's kids through college if I take this up in earnest.

One of the benefits of starting in STR3 is that all the concern over high-hp builds is off the table for now. Stock power (or less) is right at the legal limit, so we're good to go.

Best,
-j

[Bill Waters]

DK, Santiago - thanks-good info. Glad to hear about matrix classes. Bracket racing has been a huge success in drag racing for many, many years.

DK pretty much nails it regarding my dilemma. Even a 350 rwhp 818 is way out of the ST classes. If one had 400 rwhp, he would be at or exceeding the wt:power of an LMP2 car (475-500bhp and 900kg). I agree with others, it's obvious the 818R will need to have more sorting. Tire/wheel optimization, aero (as Santiago suggests), etc. have a way to go before we can expect to run with monocoque- tubbed RSRs and the like - if ever. But the simple fact is that we have limited options.

[D K]

I believe in the current iteration, the 818 is limited by tires/grip

[Grintch]

I am somewhat surprised we can't fit bigger tires, especially for the R model. Heck, my stock STi front tires are too big to fit, not to mention my wider autocross/track tires.

350 whp fits fine in STR1, you just can't run full slicks without running ballast. And 400whp would be very expensive and be pushing the limits of the block. This why the WRX/STI is not competitive with the Evo in classes that allow more engine mods.

[Bill Waters]

Agree with DK, Grintch. In fact, one of the things I am going to do when I get my kit is to get to work planning mods for the wheel wells/flares if feasible. Like all such projects, the trick will be to get more tire under there with
out ruining the terrific lines of this car. Re: the hp issue - my goal will be to have a reliable bottom end that can support 325-350 race after race.

[D K]

320 is no problem for the EJ25 bottom end.

[Santiago]

Agreed on the tire/grip limitation - which is a heck of a thing to say given the lat-G that the R is already posting. That's not a slam against the R by any means, just a testament to how far the performance envelope has been pushed now in the upper classes.

I think more than a few of us are looking at what we can do with those fenders. :rolleyes:

The JDM EJ207 V7 has a fully forged rotating assembly, and the V8 has a forged crank and rods (hyper pistons though). The Subbie crowd has been very easily getting 350 reliably out of these for some time now.

Best,
-j

[D K]

Yes but I was referring to the EJ25.

Those you mentioned were EJ20's.

You CAN get 350whp out of the 2 liter, but someone was asking race in, race out.

Its EASIER to get 320 reliably out of the 2.5, than the 2.0 - but it definitely can be done.

The V7/8/9 blocks are nice with the 9mm liners but the GRB Spec C is better at 13 ;)


Im choosing the 2.5 route this time around for a few different reasons....

[Bill Waters]

Hope our OP, DK won't mind a slightly tangential question: are ABS systems allowed in STR? What about SU? I am at the point of getting all the ABS and other braking hardware out of my donor. I will be using the large slotted/drilled Wilwood system n my car.

Thanks, Bill

[Scargo]

Santiago, I love the "it should be viciously reliable" comment.
I am not interested in enduros (and don't have a crew/money), and perhaps not willing to do wheel-to-wheel combat. I have a long-time HPDE buddy, who thinks you have more fun, more play time, when you just do HPDE's.
However, I have a slight competitive streak and I'm not sure if just knowing I did a good lap time (that would make Tazio proud), is enough. I sure intend to try TT's, if only to say I've done them. Time Attacks??

I know I can have a viciously reliable engine and perhaps go fast enough to suit me. There is a reason I am currently in a 400 whp STI rather than a Miata. I've "been there done that" with an SCCA racer where you just wait and wait... I think they call it building momentum.
If I could run ST1 I might go on a HP diet...
DK you mentioned "a better wing". Really? That wing's not good enough for 5:1 w/p?

[C.Plavan]

I can tell you from experience, once you race W2W- HPDE, DE's, Autox's will not do it for you anymore. The last time I Autox'd, that was 1996....

Then the $lippery $lope begins!

[D K]

I can tell you from experience, once you race W2W- HPDE, DE's, Autox's will not do it for you anymore.

Now THAT is a fact!!



If I could run ST1 I might go on a HP diet...
DK you mentioned [/COLOR]"a better wing". Really? That wing's not good enough for 5:1 w/p?



818 being a tube frame car, it would be in STRx, not STx

Running in STR1 would put up up against some very high hp (and weight) cars.


The wing....I think it's ok. Nothing special.
The aero can be optimized for sure, specially in the back. It doesn't need that huge air scoop for instance (but you would need a2w)

Also, I think I am going with a double element straight wing, not a '3d' wing which is designed for tin top cars.

My cousin runs the aero program at OSU and they have won the FSAE for a couple of years, so he is looking into some CFD stuff.

[Scargo]

CFD stuff? Wow, keep me/us informed on what you find out about aero. I know very little. I just stick cool stuff on and hope for the best...
I was thinking the same thing about the (passenger-side), scoop. Seems excessive and/or not optimal.
A2W sounds like a good idea! Car's light enough that it can handle some gadgets and whirly-jigs.

[D K]

For me, it's not about extra gadgets so much as it is about shortening the charge air piping.
Even though I would MUCH prefer an air cooled IC for road racing, I will end up with A2W for the fact that it's shorter.

We are probably going to lower the cowling somehow and running a tonneau cover. Not sure yet.

[SixStar]

Here's a GREAT thread on NASA and the 818. For now it's going to be relegated to the STR classes only FYI. We're aiming for STR3 on 245s with a WHP of 221. The weight of the car will lend itself to being fun and safe at that HP level with those tires while being able to keep heat in them.

http://nasaforums.com/viewtopic.php?f=37&t=108548&hilit=Factory+Five

Now for Solo.... it'll get the BEANS with as much power as the 2.0 will make coupled with 295s on 11" rims. Oh yeah!

[D K]

Yea, I'm pretty familiar with that thread lol :p




Here's a GREAT thread on NASA and the 818. For now it's going to be relegated to the STR classes only FYI. We're aiming for STR3 on 245s with a WHP of 221. The weight of the car will lend itself to being fun and safe at that HP level with those tires while being able to keep heat in them.

http://nasaforums.com/viewtopic.php?f=37&t=108548&hilit=Factory+Five

Now for Solo.... it'll get the BEANS with as much power as the 2.0 will make coupled with 295s on 11" rims. Oh yeah!