redtopz

Some of us T1 racers have been talking about where to race our cars next year. Now it sounds like PTA cars might be in the same boat? One idea that I think sounds attractive is Spec Corvette. Two of the most popular classes in NASA and SCCA seem to be Spec Miata and Spec E30. How about a Spec class for vettes that would result in relatively inexpensive high performance racing in very closely matched cars. Spec racing is nice because results are more dependent on driver and car setup and less on expensive parts. There is still a slight chance that SCCA will reverse their decision to change T1 next year, but I think it is pretty slim at this time. If they do, we would likely remain in T1 next year.

However, if the changes go through, then our intent for Spec Corvette would be to basically keep the 2012 T1 car unchanged and simply start racing. We would submit RFP's to NASA, NARRA, possibly even SCCA and see who wants our business. Some of the outdated and compromised rules for Touring racing would be removed and some new rules would be submitted to allow greater flexibility and longevity of the class. Examples would be, no wheel size limitations and only tire size and compound limits. Also, flexibility to allow any corvette to run any engine (ie. C5 with LS6, LS2, or LS3) at the corresponding weight for that engine. Right now a C6 can run an LS3 with no headers at 3450 lbs or an LS2 with no headers at 3180 lbs and a C5 can run an LS6 with headers at 3180 lbs. This seems to result in closely matched cars. Our tire size limits are 315 square and shocks are open. Must run T1 suspension kits. Brakes may be 4 piston on rotors up to 5% larger than stock. Poly and delrin bushings are allowed. The key is stock engine, transmission, clutch, and diff ratio. A quaiffe diff is allowed as are SKF hubs and upgraded cooling for all fluids.

How much interest would there be from the corvette racing community for Spec Corvette? I think this could be a fun national class with very close competitive racing. We would seek contingencies equal to or greater than any other Nasa class (might be able to attract new contingencies with a corvette-only class). I think there would be easy crossover between organizations just as there is for Spec Miata (at least regionally at first). Or should we all just blend into an existing class somewhere? Thoughts?

jtmck

redtopz,
Could you compare the T1 rules to ST2 NASA rules and suggest how to bring them together?
I think the big differences are wings and suspension allowed in ST2.
Would you think one would have to add to their car or the other take things off their car to be equal?
Have T1 and ST2 ever run together before? Do we have real time differences?
I am just starting a conversation. I think the proposal is a good one and there should be a way to make it happen.

Jim M.

rfn026

Wasn't this tried a few years back with the Corvette Challenge series sponsored by Corvette Central? They had a series going for a few years.

It just sort of died from lack of entries - or something.

Richard Newton
Like Me

PushinTheLimit

I brought up this very same discussion with some of the southeast Nasa corvette drivers and their thoughts on a Spec Vette class. To prep to the top level of an ST2 car is quite expensive. By the time you add aero, shocks, big brakes, bigger wheels, etc... it can add up quick.

Our thought was to basically use a PTA vette as the base and go from there. The rules would include the following:

1) 8.7/1 weight/horsepower ratio (This could be any number)
2) Set a minimum weight
3) No aero
4) Open brake kits
5) Open rotors
6) Tire size limit (315 would be a good start)
7) Bushings open
8) Swaybars open
9) GM clutch

Someone brought up just using spec shocks, but I doubt T1 racers would be up for that. So open shocks would work, but I would say leave it open if someone wants to run coilovers. Just gives the class more diversity and options to go with and possibly more contingencies with different shock manufacturers.

I've always thought with those rules, it would make for a competitive class but still leaves racers options on how to setup their car to the way they like it. It still wouldn't be cheap, but it would be cheaper than running ST2 as it is.

drivinhard

yes we discussed this 2 or 3 times in the SE.

everybody wanted to leave "open" what they had already modified on their car

Personally if you are going to do it, I like the idea of leaning towards keeping them VERY stock (ie, no $10k penske shocks or coilovers) but allowing ANY C5/C6 part be updated/backdated. So you'd have a variety of engines, transmission gearing, shocks, bars, you could play and tune with from track to track. That gives you an inexpensive box but one you can be creative with.

I think working off of a power/weight formula would be easiest to get the LS1/LS6, LS2, LS3, and LS7 cars all fairly equal.

Open brakes with maybe a limit on rotor dia and material (iron, no carbon, etc)

also when I say leave them stock, I mean don't modify stuff. removing anything and everything I see as legit. I think it's stupid to have a "race car" that has to have a dash, carpets, and HVAC, or whatever.

the clutch (the factory hydraulics are junk and the safety aspsect of a cast 55 lb rotating assembly 6" from your right leg at 7000 rpm) and the windshield (I don't want to replace cracked $500 OEM glass ones every 3rd event) are two more things I'd consider for modifying

ScaryFast

As soon as you get into a spec class discussion you have to consider the engine. A spec Miata engine is $1000 for 110 hp, and $15,000 for 112 hp. That's the diffference between first and last in an otherwise equal car. Is power to weight the answer? Maybe. But only if torque is factored in as well.

So we keep it to Corvettes. Then what happens when the C7 comes out? Where is it going to fit? And where does my C4 fit? Sounds like you don't have a place for me in your rules yet.

It's a great idea, but we'll never agree. T1 guys don't want to bend to ST2 rules and ST2 drivers aren't going to remove aero and everything else to go toward a T1 rule set. One side is spending a lot more money than the other.

TCC tried it, but nobody showed up and the series dissolved. NASA even allowed them their own series points tracked in addition to the points earned in standard NASA classes. The crew showed up for about 3 races and then disappeared.

Those who are unhappy with the rules will be on board, but you need enough people (read: enough money) to be in play for the organization supplying the "place to race" for it to be viable. So a handful of unhappy people who can't buy a new race car to fit into the appropriate series try to agree on a rule set and what Mark said above is what happens. Everybody wants to make the rules suit their existing car.

Trust me, I am not opposed to this concept, I'm one of those people that has a car that I can't get classed in what I feel is the appropriate spot, but I am the only person in the country with this specific problem, so why would I get special treatment? I can go buy a better car just as easily as all of the T1 guys can...

redtopz

This class would not be intended to take cars away from ST2. ST2 would continue to be an open mod class with just a hp/wt ratio and many makes of cars. Spec vettes probably could run ST2 if they wanted to, but might not be competitive.

The nice thing about Spec Corvette is that we only have to worry about corvettes, which is easier to manage. Plus we have a pretty tight community and we would all want the class to succeed. Can a C4 run an LS6 engine? We talked about requiring stock engines, trannys, and diff ratios, plus a hp/wt ratio of around 8.3:1. Then setting maximum weight limits would not be necessary although a minimum race weight would be a good idea. I think open clutches might also be a popular rule. No aero mods allowed at all similar to T1. Bushings limited to rubber, poly, or delrin. Dry sumps allowed.

Regarding suspensions, I can see 3 options:

1. Open suspension (leaf springs or coils) and open shocks and sway bars. This would allow more corvettes to run spec corvette with the parts they have, although it wouldn't really be very "spec"...

2. Spec T1 leaf springs with open bars and shocks.

3. Spec suspension and spec shocks (T1 leafs, bars, and sachs shocks).

I would probably lean toward option 2 even though I currently run Option 3. T1 springs are not that expensive and everyone would be running the same spring rates with slight variations between C5 and C6. They are slightly stiffer than stock and allow lower ride heights. Then run whatever bars and shocks you want. Remember that it's never possible to get cars exactly equal unless it is 100% spec. Our group of T1 cars in CA run remarkably similar lap times and seem very evenly matched despite different setups with engines and shocks. It's always possible to build a faster car with more $$, that's racing. But this would be a fun class with very little compromise. You don't have to run 245 tires to stay in PTA and you don't have to spend $30,000 on mods and aero for ST2. Just something to think about.

JerryTX

New racer here running a former SCCA T1 dry sump LS2 car that I'm now running in ST2. It is still in T1 trim (crappy shocks and no aero). Its almost unchanged from T1 specs but I am upgrading the front brakes (sorry, C6Z06 calipers don't cut it for full time track use). I like the idea of spec vette yes!! Given the economy I'd say go with a spec shock and T1 bars/springs.

ScaryFast

Agreed, but that also means that car counts are insignificant. In my region (midwest area) there are about 6 to 8 regularly participating NASA Corvettes between ST1, ST2 and PTA, plus about 4 T1 cars. Of these 12 cars there is a wild difference in prep and performance. So we're not going to get all of them into the same class. We're back to someone spending money.

ST2 is growing because there are now competitive Lotus, Porsche, Mustang, and AWD Mitsubishis and Subarus joining in the class.


Sure, mine does. That's why I can't get it classed anywhere other than ST2 against much faster C5 and C6 cars.

jtmck

My car is ST2 NASA
On the numbers above:
1 I am OK there
2 I am OK there
3 I can remove my wings, Does the nose have to go back to stock?
4 I am OK there
5 I am OK there
6 I can size tires down in the rear
7 I am OK there
8 I am OK there
9 I have Spec 2 clutch.

OK, If I remove the aero and put on 315 rear tires, the only question is the clutch, Is that the way you see it?
Would I then be a "spec Vette"?

Thanks Jim M.

Black89Z51

I'm pretty interested in this as well.

I ran a NASA event a couple weeks ago, the first time with this car. I classed myself, and with what I've done, it was PTA. I'm running a 3270 lb car (with me) and 322 hp. Almost dead on 10:1 ratio. I've got mostly safety and handling stuff done to the car with reliability mixed in. All that's done to the motor is 0.5:1 higher compression, a cam, and a conversion to carb. Stock crank,block, rods, heads (except dual valve springs). I didn't even bore it.

All that being said, I'm 4-5 seconds slower than PTA cars at Summit Point (probably more if you figure in faster ones). Or at least the 1 other PTA car that was there, who left Saturday. I figure if I can get to 8.7:1 power to weight, I could probably keep up.

If people could class their car to be PTA legal, I noticed that the other PTA car there was running very similar times to AI. Could AI be a possible group to run with with limited mods, such as T1?

drivinhard

I'd say stick to factory for suspension, any 97-13 shock (save for maybe the magnetics), any spring (including GM racing T1), and any 97-12 sway bars (including T1). Beyond that, stuff gets pricey and there's a zillion combos you could run even with just the C5/C6 parts inventory.

Open suspension gets pretty expensive, you're halfway to ST2 at that point. These cars don't need fancy parts to go fast, our PTA/TTA times (factory stock suspension with T1 bars) at road atlanta and VIR are nip and tuck with T1, and that's running on 245-275 tires, things T1 guys would their head at.

I think the C4 could be included with maybe a power/weight adjustment. C7 I don't see as an issue, can't imagine they'll be droves of them lined up to race right out of the box.

Black89Z51

The problem with this is getting the power. Building engines gets expensive, even at the 8.5:1 level, and only so much weight can be taken out of a C4. I could change for Lexan and save a few lbs, but that's expensive-ish and then you have to add supports, which block my view. I'm even running a carbon fiber hood with no under tray support. I removed approximately 60 lbs of wiring when I went carb. I've got a Sparco FIA approved seat which is pretty light. I even removed the front bumper (not the cover, but the composite/plastic bumper absorber)

I just don't see where I can lose much more weight, so that leaves adding power.

trackboss

FWIW, Doug Davis started spec vette with nasa about 1997 and it went no where. Later on nasa had the vette viper challenge with 3 different classes from close to stock to very well prepared. That would have been pretty nice, but it also went no where.
IMO, having too many classes just lessens the car counts.

drivinhard

you couldn't buy a C5 for $12k then either

trackboss

For spec vette they were using C4's back then with minimal mods. The cars were really cheap. Bolt in cages and all, but they ran on real slicks and ran pretty fast.

zigspeed10

I'm all for spec corvette

Lets list the allowable modifications from the other successful spec classes like spec miata or spec e30 and see if we could mimic them to some degree.

Spec miata

Engine - ?
Spec trans
Spec shocks
Spec springs
Spec roll bars
Spec brakes
Spec tires


Spec Corvette

Spec lbs/hp limit(limit on peak torque)
Spec m12/m6(maybe a hp/lbs adjustment)
Spec shocks(OEM Z06 or some cheap alternative)
Spec springs(OEM Z06)
Spec roll bars(OEM or T1)
Spec brakes(OEM)
Spec tires
everything else is stock(would have to spec out what could be removed from the car, allow some cooling mods, and have a debate on stock clutch vs. any clutch)

To be realistic, the Grand Sport and C6 Z06 models would have to find somewhere else to play. This class would accept all C5 models and base C6 models.

To call it a Spec Corvette class then the parts need to be spec. A hybrid T1/ST2 car doesn't make alot of sense. Think about it, we already have this and there is not enough participation and its too expensive. If this formula worked we would already have 10+ car fields on a consistent basis. A successful spec class requires affordability and close competition.

andy3101

Some good points here. I like the idea of getting more corvettes on track!!! Scca STO or nasa st2 looks like a catch all class for the corvette.

Just to make an arguement that a T1 car can run with a STO car I point out lap times from John buttermore... He just ran a 134.7 at gingerman in a 3600lbs c6 T1 car ls3 and the STO record is 135-136 in a 2950 c5 ls6 with cam and headers. Tom sloe in a c5 T1 car ran a 137-138 at ginerman this year.

This year at mid-Ohio John buttermore ran a 134.1. Again 3600lb ls3 grand sport. Dave Pintaric in his awesome and really fast sto viper ran a 132. Next closest STO ran a 135. 2980 ls6 c5. (head cam header package)

I argue that just by taking the weight off of the c6 grand sport ls3 from 3600 to 3300 John buttermore could run just as fast as any STO car on track right now. (I believe John has said he adds a ton of ballast). (no cost to John to change car from T1 to STO and still be competitive)

My vote is to have all the corvette guys run STO!!!!

sperkins

So what club/organization is someone going to pitch this to?

Black89Z51

There is AV8SS on the west coast. If there was enough interest it may be able to be restarted on the east.