RX8Club.com - SCCA Members: Letter request

As you may know I built and campaign an RX8/Renesis in STL. The car is not as competitive as it should be but SCCA has recognized this and has made some changes to help it out. The most recent one was to decrease the weight to 2700 pounds. For those not familiar with racing, this means that as you drive off the track after the race, the car must weigh at least 2700 with whatever fuel you have plus you and all your gear.

Most dedicated track builds seem to come in around 2600 pounds dry, which is about where mine is. I'm 200 with gear if I don't run a 40 pound cool box.

Yes, 2700 is probably achievable but it gets increasingly expensive to add lightness. A better approach would be to get rid of or enlarge the restrictor plate. This would cost less than $20, everyone could take advantage of it, and would achieve 'essentially' the same thing with respect to parity.

If you are in support of the above, please support my proposal (quoted below) #26640 To do this go to:

https://www.crbscca.com/ complete the required info and select club racing/Street Touring/STL. Please be respectful and just say you support my request (26640)

Thanks.
Alan

Gentlemen,

Thank you for your recent rule change to make the Mazda RX8 with Renesis engine more competitive in STL. (Request #27581, weight dropped to 2700 pounds). While I agree that this platform “needs help”, I would suggest it be achieved with a larger restrictor plate rather than less weight. It may be too late but here are my concerns.

I built an RX8 from scratch specifically for the STL class. With me and gear (200 pounds), it weighs about 2800 without fuel or cool box. My car has less than 5 pounds of optional cage, doors are aggressively gutted, carbon fiber rear deck, Lexan rear windows, etc. Several of the RX8 race cars in SCCA are previous pro cars (PWC, etc.) and have much more cage.It will be very difficult and expensive to get my RX8 down to 2700 pounds in STL. For the unfortunate souls in PWC cars it will be impossible. I can probably remove another 50 pounds with exotic composite for my splitter (instead of plywood), lithum battery ($1500), custom harness, custom aluminum bumpers/crash structure, and other little things here and there.

I’ve included a dyno plot from today on Tom Fowler’s Dynojet of my car, with and without the 55 mm restrictor plate. The plate is good for about 10 HP peak. Peak torque is unchanged but is about 5 lb-ft higher beyond 7k PRM without it.

In summary, while the weight reduction is appreciated, few, if any RX8’s in STL will be able to take full advantage of it. A restrictor plate enlargement would be much easier and far less expensive for all competitors.

Thank you for considering my request.