Car #: 23
Year : 1995 Posts: 912
quote:Originally posted by d mathias: If it doesn't say you can...
Or even better: if it says you can't, you can't.
"m. Exhaust system 1. The exhaust manifold must be Mazda OEM, without any material added or removed. No coatings are permitted on the exterior or interior of the manifold. Heat wraps may not be used."
If you'll recall, the 2009 SCCA Runoffs champion had a heat wrap on his exhaust. It was deemed legal since the total diameter of the exhaust pipe with the heat wrap was not bigger than the 2.25" the rules allow.
NASA doesn't have the heat wrap rule though.
"12.6 Exhaust System The stock down pipe must be used. However any single exhaust pipe may be used, providing that it has a maximum outside diameter of 2.25 inches (+ 0.0625 tolerance)."
So for NASA you would then indeed need to fall back on the rule of "if it doesn't say you can, then you can't." Although I think there is still an argument to be made that if the pipe with heat wrap does not exceed 2.25 inches plus the .0625 inch tolerance, you're good.
Thread hijack: I love "tolerances". Why not just increase the maximum diameter to 2.3125"? Reminds me of the NASCAR pitlane speed limit rule where they have the speed limit of say, 55mph, but they then have a "cushion" of 5 mph. Drives me nuts. To "limit" something is defined as preventing it from becoming greater than a particular amount or degree. So by definition, if there is a cushion, it's not a limit. 55mph is then just a guideline, a preference, a suggestion, a request, whatever. But it's sure as hell not a limit!!!
-------------------- Rob Gibson RJ Racing 2010 NASA Nationals TTE Champion 2008/2009 WERC Champion 2007 NASA SoCal SM Champion rjracing.net Weekend-Racer.com
Year : 1990 sm 1990 ssm 2007 MX5 Cup Posts: 62
Sorry for newbe ?. I had my 1990 on the lift today, should this car have a heat shield? The previous owner had the pipe wrappped. He raced with the car in SSM class last year, I quess he was not legal, from what I am reading here.
Car #: 30
Year : 1991 Posts: 62
Let's be clear on this one. They say the "exhaust manifold" can't have wrap. That would be the 4 into 1 collector (the header) up at the engine end. After that isn't the exhaust free? If it's free doesn't that mean you can do what ever you want as long as it exits after the rear axle. Last year I had a springfield dyno exhaust with the muffler can wrapped (to control heat in the cabin) and a section of the tail pipe near the diff wrapped (to control heat on the diff). The header was not wrapped...because that is illegal.
Also, I would check with your local scrutineer.... at my first SCCA race after racing for several years with NASA, they almost DQ'd me for "illegal coating on the exhaust....." I had painted the heat shield that bolts onto the header with engine paint....
common sense eventually won the day, but not without a few tense moments on my part. Other DQ's had put me into 3rd place.... and I thought I would be next!
Needless to say, before the next race I painted that part silver to match the factory coating!