Lower HP Tube Frame Cars

[claykos]

Greg, have you thought about classing lower hp tube frame cars? Something like an SCCA GT3 car? I would think they would fit decently into ST1/2. In actuality there isn't really much difference between a tube frame car and a real factory prepped race car like a GT3 cup car or PTG BMW M3. They are basically a tube frame inside the factory unibody.

 

Porsche GT3 cup cars and Panoz run in scca GT2. A GT3 cup car actually won the runoffs this year. Fast lap for the Porsche was a 1:45 and the fast lap for a tube frame Nissan in GT3 was a 1:47.

 

Thoughts?

[David M. Pintaric]

Greg,

 

The GT2 & GT3 guys are looking for an alternative. I think a unrestricted Viper (460 and higher RWHP @ 3400 lbs) would run with the GT2 cars pretty well.

 

Just a thought...

[Greg G.]

I was going to class individual tube frame cars this year, but we ran into a huge classing issue, and NASA decided to only class tube-frame and non-production cars that were "spec-type" builds, like the Panoz and the Pro-Challenge cars.

 

Basically, there was no satisfactory formula for classing the GT2 and GT3 tube frame cars. I spent many hours researching this issue, and it came down to either applying such a huge modification factor to them that most would not be competitive, or having a lot of very unhappy production car owners getting beaten handily by $25,000 stock cars. Our own NASA ASC (American Stock Car) tube frame vehicles proved at an adjusted wt/power ratio of 7.7:1 to be generally faster than Viper Comp Coupes on slicks (less than 5.5:1 adjusted). These cars only make about 330 rwhp, but they are just wicked fast. They would require a modification factor of about

-2.5 to even them up with the other ST1 cars. Applying the same modification factor to all tube frame cars would kill their chances at being competitive (like the GT3 and GT Lite class cars). However, since there is no real formula to what constitutes a car in those classes, and the cars are equalized by their weight requirements, it is very difficult to come up with a "formula" that will work for individual tube frame cars. So, for '07, they are off the table. However, we encourage those drivers that are interested in ST to participate in SU this year, so we can study them, and try to come up with a method of classing them fairly.

[claykos]

I see....

 

What about Grand Am Rolex Prep 2 cars (the nonnamaker GT0's for sale are ohhh so tempting!)? These are tube framed cars but are designed specifically to compete with the GT3 Cup Cars and old PTG BMWs. They are technically tube frame, but would there be an exception for these cars so they could run ST1 against the cars they normally competed against in Rolex?

 

Also from what I have seen at PIR in the last few races the ASC cars are extremely competitive with the fast ST1 cars and actually someone in a speed GT spec Viper CC on toyo's (ST1) went 1:02 while the fastest ASC was a 1:04. I think an ASC car as sits would be competitive but not dominant at all in ST1.

[bpanther]

The heat is on....

[FrankBarba]

What motors for the Pro Challange Cars???? There are 4 different motor combo's??? ZX11 - ZX12 - ZX14 & Ztec Ford Motor.

[Greg G.]

What motors for the Pro Challange Cars???? There are 4 different motor combo's??? ZX11 - ZX12 - ZX14 & Ztec Ford Motor.

 

I'm waiting to here back from the builder of the Pro Challenge Cars. Currently, their classing is still pending until we have more information.

[RJSmith]

If the ASC guys would change there set ups to make the car stiffer they would beat the ST1 cars by a lot. But because they little the car to drive little a bus they are slower. Just my thought.

[944-Spec#94]

Also from what I have seen at PIR in the last few races the ASC cars are extremely competitive with the fast ST1 cars and actually someone in a speed GT spec Viper CC on toyo's (ST1) went 1:02 while the fastest ASC was a 1:04. I think an ASC car as sits would be competitive but not dominant at all in ST1.

 

Clay remember that PIR may not be the best track to compare a Viper comp coupe to an ASC car. The track at PIR does not really allow the faster cars to really streach their legs and really see performance differences especically in high speed cornering where efficient downforce or a well developed suspension to handle highspeed bumps/elevation change really make a difference. Your car is fast at PIR, but I believe that at sustained higher speeds like at Willow Springs that be different due to the impact of aero. If you want to compare ASC cars to other ST cars best to look at PIR, Cal Speedway, Willow Springs, Buttonwillow and Mid ohio to get better idea.

[claykos]

Yes clearly from track to track there will be differences. And actually I would think on a bigger track like Willow or Fontana the Vipers and GT3 porsches would have more of an advantage over an ASC car because of their more slippery aero (with better downforce) and higher power to weight.

 

And there is always the nut behind the wheel.....makes the biggest difference and that is why it is so hard to make classes for a "club racing" series like this. There is a huge variance in the drivers. A pro in an ASC car went 1:44 at Fontana last time I was there, but a lot of guys were having trouble breaking 1:50.....

 

It will definitely be interesting and I am looking forward to it!