Rolex Grand Am GT Rules

[thebrander]

What is it about the Grand Am GT rules that favors the RX8's so much? Anyone from Stevenson here?

[Beauwulf]

Originally Posted by thebrander

What is it about the Grand Am GT rules that favors the RX8's so much? Anyone from Stevenson here?

It's not the rules that favor the Mazdas. It's the years of development on the car. The engine is pretty much the same year to year so the development is already done. Plus, it is a great car to start with....

Stevens is working on new aero and some engine development as well. The chassis they use is the same one from the G8 they ran before. I think with some time to work out the kinks, they will be competitive!

[thebrander]

Originally Posted by Beauwulf

It's not the rules that favor the Mazdas. It's the years of development on the car. The engine is pretty much the same year to year so the development is already done. Plus, it is a great car to start with....

Stevens is working on new aero and some engine development as well. The chassis they use is the same one from the G8 they ran before. I think with some time to work out the kinks, they will be competitive!

I agree that the RX8 is a good car to begin with and the race cars are well sorted out, but in stock form they can not hang with the cars they beat today even on a roadcourse. I remember hearing today about the M6 getting rev-limited since the last race. I just came across this tidbit http://www.grand-am.com/news/index.cfm?cid=4345 about how the rules make cars like the RX8 competitive with the big V8's. The RX8's weigh in at 2200 lbs. I'm guessing the Stevenson cars come in closer to the max at 2800 lbs. My guess would be that the higher horsepower cars have a higher allowed minimum weight (anyone know for sure?).

I'm still doing my homework here, but the ALMS corvettes come in around 2500lbs with 485 hp. They would run circles around the RX8s. The LG corvette did not have a very good showing today for the same reasons you listed for Stevenson. They are still sorting out a new car. I speculate their ALMS car from last year would have run in the front today, which is why I'm trying to understand the handcuffs that the big boys have to where.

BTW, I have a feeling Stevenson might eventually dominate (ok, just hoping ).

[thebrander]

Pretty cool summary of each car's spec limits: http://admin.grand-am.com/assets/GTrulesforweb3.pdf

2-5 Chevrolet Camaro
2-5.1 Stock LS6.
Stock LS2 engine # PAX0662 with spec cam and installation
Contact: Jeff Kettman at jeff.kettman@gm.com
2-5.2 Minimum weight 2750 or 2860 lb with DP transaxle
2-5.3 Five-speed transmission
2-5.4 Allowed #2301-E2-0900R&L front spindle
2-5.5 Allowed #26E1-0201W upper control arm assembly
2-5.6 Tire sizes are 305/660-18 front and 305/675-18 rear.

2-15 Mazda RX8 (Prep 2)
2-15.1 20B Cosmo three rotor (Mazda Spec parts). 2.0 liter, 9.7 compression ratio, 3-52mm throttle bodies, maximum of 6 injectors, maximum fuel pressure 4.2 bar, intake manifold is free. Maximum RPM 8600. Call GRAND-AM for parts list at 386-681-6681.
2-15.2 Minimum weight 2220 lbs or 2310 lbs with DP transaxle.
2-15.3 Six-speed transmission.
2-15.4 Maximum body width is 73.5 inches.
2-15.5 Engine set-back 5.125 inches from spindle centerline to 1st spark plug.
2-15.6 Complete rear wing height w/ end plates cannot exceed roof height. 2-15.7 Fuel capacity 24 gallons May use oil in fuel. May machine the blue fuel rig restrictor
to an inside dimension of 1.200 inch with square edges.
2-15.8 Allowed larger/higher exhaust position.
2-15.9 Tire sizes are 285/645-18 front and305/660R18 rear.
2-15.10 2009 Mazda RX-8 "R3" bodywork permitted with 3" maximum front splitter dimension.

Looks like the Camaro still has a much higher power to weight ratio than the RX8's. I think your right Beauwolf, the RX8's are just more mature right now.

[racer50200]

Originally Posted by thebrander

Looks like the Camaro still has a much higher power to weight ratio than the RX8's. I think your right Beauwolf, the RX8's are just more mature right now.

Do you have some knowledge of how much horsepower the 3-rotor Mazda is making??

[thebrander]

Originally Posted by racer50200

Do you have some knowledge of how much horsepower the 3-rotor Mazda is making??

I actually retract my statement about the Camaro having a higher power to weight ratio. The racing engines in the Mazdas evidently make well over 400 BHP. I can't search for the link right now, but I'll try to remember to dig it up tonight. They'll definitely need to change the rules for the RX8's. At 2200lbs with 400+BHP, there is no excuse for them to lose a race against the current handcuffed competition. Ever.

[thebrander]

Couldn't wait. Here you go: http://admin.grand-am.com/grand-am10....cfm?cid=24614