montoya

So I've been going over the rules, and I think I have it correct, but does anyone know for sure how a 2010 GT3 classifies in NASA TT?

So the way I see it, my car has a comp weight of 3390 (with me in the car, after a session with low fuel, measured by NASA), rear wheel horsepower of 423 (dyno by NASA authorized shop), giving me a base unadjusted power to weight of 8.01.

Now, add .1 to that for being between 3300 and 3400 pounds- that puts me at 8.11, or just over the TT2 limit of 8.0.

Now there is a penalty for running slicks, but no penalty for running Hoosier R6 since it is a DOT tire, right? If I run slicks the penalty is -.75 on the power to weight, which would put me in TT1 for sure.

So am I correct? NASA is new here in the PACNW, so I thought I would ask here for a quick sanity check...

cec3

Classification is correct. No penalty for R6's (or A6's for that matter). This is assuming you are running factory aero as pictured in avatar. Sounds like you still have some room to add a little weight in gas tank if needed as TT sessions are very short. Enjoy - TT can be fun.

montoya

Thanks for the reply. One thing I have clarified is that non factory aero has no penalty in TT1 and 2, only TT3. But yes, right now I have factory aero, but I can imagine at the nationals for NASA that wings are popping up like weeds in TT1 and TT2. So far I don't feel the need, but maybe a cup wing....

jrgordonsenior

423 rwhp seems high for that car. Is that normal for 2010's?

You'll want the cup wing at Miller for the high speed sweepers. There's lots of 3rd and 4th gear turns....

montoya

No, not normal, Akrapovic + tune. Good advice for miller.

AudiOn19s

Sadly...the TT rules are not very Porsche friendly.

The exception is they made the 996 GT3 a little more competative with the new TT3 rules vs. TTS where it was previously classified. I have been toying with the idea of doing a TT with my car this year now that it may be a bit more competative.

montoya

^ Well now the TT2 class as shown in my first post is pretty good for the GT3 .2 and .2 RS since you should be right at the limit for the class on power to weight. I'm not sure what your rear wheel HP is, but lets just say 375 with a race weight of say 3250 that gives a HP/wt ratio of 8.66 which is TT2- so you could loose weight or maybe run racing slicks (-.75 HP/wt reduction) and still be in TT2. Plus aero mods in TT2 are unlimited without penalty. Otherwise with less HP more weight you could probably be at the limit of TT3 but no aero mods without a penalty...

ukrbmw

Andy - I would disagree. I ran TTS with my old car and was a 2-3 seconds off the pace of the fastest Corvette in the country. This was with a street car, 350 pounds overweight, stock gears, A/C, radio, and no setup work (I drove it as it came). It was also my first season in the car on somewhat used up A6s. At local events I used to win by a couple of seconds.

I think a properly setup 6GT3 with all the highdollar toys will be pretty good in TT3. Now you can detune or use a restrictor to get a more broad power band and run stock aero.

Going to Nationals you will need all the latest and greatest. Corvettes you will run against will have it and they have a lot of experience setting those cars up.

To the OP - I think you're better off running a restrictor and staying in TT3 with stock aero. 997.2 cars have great stock aero - it'd be crazy not to take advantage of a freebie!

AudiOn19s

Fair assessment Alex. TT3 makes it better for us because the vette's loose aero and power to weight comes back to 9:1 which puts us in line with what our cars make stock power wise. Unfortunatly my region is one of the ones with the fastest corvette's in the country (Danny Popp and all of the killer cars that come out of his shop). My car is similar to your old car in prep minus the re-gearing your car had.

I ran a 1:35.3 pro course at Mid Ohio a couple weeks ago on Nitto's. Heading up this weekend to see what the winning TT3 time is...my guess is somewhere around a :31-32 which means I might have a fighting chance with a little weight loss and some A6's but it's probably still a little out of reach.

p.s. How's the race car treating you?

montoya

That's a lot of restriction- about 50 whp, or I would have to add 500 lbs- which is not allow (max 250lbs ballast).

I looked at the winning time at Laguna with TT2 it is about 2 seconds faster than Randy Pobst in a stock .2 RS with R comps or 4 seconds quicker than the fastest DE RS on Hoosiers, so there is a significant gap. Could I close it completely, probably not- but I think it could be close. With better aero like a cup wing it would be better. I know that my car against the fastest .1 RS (PJ's) with similar hp/wt is 1.5 to 2 seconds slower at ORP (could be me) but the main difference is aero (cup wing) and gearing (4.25 vs std RS). I think Pj's car could match the 'vettes with PJ driving. So, there is hope for me (maybe)...

ukrbmw

Andy - yep, Danny is who I ran against in TTS and I think his and Forbis car are the fastest in the country. I didn't have Cup gear - just stock ratios and they weren't bad. I did have the R&P.

In my testing A6s were 2+ seconds faster than NT01s at VIR, so you should be pretty close to that at Mid Ohio since it is all about grip there. I think you are very close - a little time and dialing in the car and I bet you'll be knocking on their door.

And race car is coming along. Had to work some bugs out and starting to get good lap times out of it. One thing I miss about the 996 - car is ready to go out of the box. I'm reinventing most everything on mine.

OP - 50 hp is not a lot of detune. And at your weight level I wouldn't even think about adding more weight. Think of it like this - detune of 50 hp and some good shock/springs and you're a killer car in TT3. To run TT2 you need the aforementioned shocks/springs, aero, potentially weigh reduction to really get to the max. Basically you're going to double the cost.

And don't forget - a corvette in TT2 will have 425 hp and 450 foot pound of torque. You're still running around at 300. Coming off the corner you will see a huge difference. A detune on your motor keep torque flat and just takes a bit of power off the top.

Basically - question is, do you want power and spend tons of money to keep up, or do you give up a little power and be very competitive for half the budget.

montoya

Well I already have everything but the aero and have spent the money. MCS, full monoball, RS gearing, GT diff, etc, etc. And I am at the limit. 3390 race weight at 423 whp, that's like just around 8.01 or less. I can make it to 8.00 with less fuel.

You are right though, I can't add torque so no doubt that is an issue, but running around with less power doesn't sound fun. Throwing out the Akra and putting a restrictive intake is going backward. I wish there were a competitive vette here running to compare. The best reference as I mentioned is Laguna, with different drivers I know against the last NASA event where a vette took TT2. That gap can be closed, but it's a big gap.

z06801

You can add aero in both TT1 and TT2, and yes some extra wing is good though the t1,2,3,4 combo and t8 which connects east and west track on the outer loop, I think TT2 times will break 2:00 this year.

wanna911

Alex, 2-3 seconds off the Forbis car? Maybe with James driving but that thing ran a 1:27.2 at Road Atlanta and a 1:57 something at VIR with Danny in it. I think that's like 5 and 7 seconds respectively than your GT3 has turned at those tracks. It's faster than 95% of the TT1 cars in the country. And that was when the weight/power ratio was 8.7:1. They get more HP now.

The rules still are not Porsche friendly. They reward skinny tires, but only if you put them on the back, nullifying Porsche's getting any advantage for having narrow front tires while the Corvettes and Vipers run 305's and I think they are squeezing 315's in the front. Much bigger tires in the front and rear than you can run without a widebody kit on a widebody 911. So basically saying contact patch only matters in the rear of the car. :/

The old TTA rules were extremely anti-Porsche. They put a C5Z in TTA as a base class but put the 996 GT3 in SUR as a base class. And the TTA guys with no wings were running just behind 6Cup record times. That is ridiculous.

ukrbmw

Ed - you're right, that makes 5 seconds at Road Atlanta. At VIR Danny did a 1:58 and that weekend I ran 2:02. I went a little faster later in the year, but conditions were better (cooler).

However, Danny had a maxed out car with best gearing and full aero, etc. I still ran a street car with full interior, 350 pounds overweight and cup lip with 996RS wing - far from optimum. I still say that gutted to max out power to weight, better aero - full grand am type front and rear setup, Cup gears, and seat time that car would've been very, very close.