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Stock car on a road course


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Hello everyone,

I've been racing my older super late model on our local road course.

Within our local rules, my car is simply in the GT1 class where I can race against anything from an exotic "Cup Porsche" and older Trans Am cars to nearly stock Corvettes. I end up somewhere in the middle with my conservative power and chassis with more oval track heritage than it should have on a road course. I am planning many changes over the winter.

Our sanction is currently changing from a lbs per displacement formula (that puts me at 2764lbs min) to the power to weight ratio similar to what is see in NASA.

My question to you all is where would a tube frame stock car chassis with a modest 450-475 HP engine and 10" slicks land in the NASA classes?

Thanks for any input.



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In order to fit into ST1, which is the fastest Super Touring class before you are considered Super Unlimited, your minimum weight would be 3090lbs if your maximum RWHP was 475.


This is assuming that you are taking power to weight modification hits for:

Tube Frame Non-Production

Dog Engagement Transmission

Non-DOT Approved Slicks

10" Non-DOT Tire Size


So it might be a bit of a stretch for you to stay in ST1 instead of Unlimited. You can add up to 250lbs of properly secured ballast to try and make minimum weight.


There is a very easy to use calculator that you can download from nasaproracing.com under the rules section. It opens in Excel.

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Thanks for the replies, even the multiple ones

I wanted to clarify my HP numbers. My 450-475 would be engine power, not wheel HP.

Nowhere near that powerful.

I've never had the car or engine on a Dyno. Comparing my performance to the crate engined (604 - 400 horse) cars on ovals, I'd say my 450-475 is close. I had an acceleration advantage on the straights, they could close in the corners with their 100 lb weight break.

Also, is there any potential for a NASA class like the SCCA has with their GTA classes?

I'll look for the calculator, thanks again.





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Well for classing, HP is measured at the wheels. So all else being the same, your new minumum weight at say, 400WHP would be 2640 lbs, and 425WHP would be minimum of 2805 lbs.


You will just have to get on the dyno and find out.


I don't think NASA will adopt SCCA classes, it would just water down the classes. ST is already pretty easy to fit into especially when you can add in up to 250lbs of ballast, and the rule format is pretty open.


Here are the Super Touring (ST) and Super Unlimited (SU) rules:



Here is the classing sheet you would have to fill out and turn in:



Here is the dyno compliance form that you would turn in with your classing sheet:



Here is the class calculator (download it and open in Excel):


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Good, the seperate "R" classes went away. Last time I looked it appeared the powers that be wanted to keep them.


Now if we could just get the power to weight for ST2/TT2 to be halfway between ST1/TT1 and ST3/TT3.

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