Originally Posted by s1mpsons

I support the consideration for reclassifying the 93-95 Mazda RX7 from ASP to BSP.
-Joe Smith
SCCA Member # 123456

Originally Posted by PedalFaster

Letters in this format are minimally effective -- letters which present compelling, data-driven arguments in support of a change are far more so.

Originally Posted by PedalFaster

Just out of curiosity, why can't the FD get it done in ASP? ASP still seems to be dominated by C5 Corvettes. An FD's considerably smaller and lighter than a Corvette, and although it would be down somewhat on power, SP-legal modifications should make up a significant part of the difference between the cars in stock form.

Am I missing some weakness in FD?

Originally Posted by boxboy

You can make 375ish rwhp on stock turbos at about 16psi. More boost than that and you are just generating heat. I'm not sure I'd go to huge tires since in ASP you'd be stuck with the stock 4.1 rear gear. With 285/18's (shortest big tire) and a 8500rpm redline you go 75mph in 2nd. Bigger tires would take you close to 80mph, which wouldn't be the best for off the corner grunt.

Not sure if the new rules would allow the wastegate to be ported. Creep is a problem at elevated boost levels and can make the turbo transition point abrupt.

Expect weight to be in the low-mid 2600's with SP rules. Competitive with a Z06? Probably some of the time, though I wouldn't want the stock gears.

-Andy

Originally Posted by boxboy

You should ask Dan Chadwick what he thinks after running his in ASP for awhile, and now prepping to SM2. Tire is not really the problem, gearing still is. I think a well prepped car could be competitive, but would be an A- car for the class. That's compared to a Z06. Given some of the other cars coming into the class like the S/C Elise, that might shift it down more.

Originally Posted by boxboy

Weight --- mid 2600's is reasonable to expect given ASP allowances. As mentioned, you need to run probably 5/8 of a tank or more of gas to avoid starve. That's a big deal when the tank is ~20gals. When I went to a 5gal fuel cell (legal in SM2), I figure I saved 100lbs of weight out of the car. Wheels and tires you will actually gain weight over a stock prepped car.

Power --- 350whp and 300tq is not unreasonable on stock turbos. I made in the 350-370whp range on bone stock turbos and motor, though it was not the most fun maintaining that system. Here's an old old link with some dyno sheets in it, including mine...http://www.siastuning.com/SMspecs.htm Note the power jump when the second turbo comes on, not the easiest thing to deal with.

Tires --- when I originally ran the car I was on 285's all around with the 4.33 rear gear (not legal in SP), and part of the reason for the 285's was keeping the gearing as short as possible. In retrospect, were I doing this again, I'd try taking the gearing hit and running a 315 in the rear just to try and make sure all the power was being used and grip through the corners was better (more speed maintenance).

All that said, when I ripped out all the vacuum lines and solenoids to put on a single turbo, that was a happy day.

-Andy M.

Originally Posted by boxboy

To answer the question on competitiveness, I'd think a full prepped car could be in the hunt sometimes, but I'd probably pick a S/C Elise or Z06 before it. I think that same car with short gears and some motor work would do better in SM2, relatively.

-Andy M.

Originally Posted by kbrewmr2

don't get me started on the *SP reorg

Originally Posted by dmitrik4

time to start up the "RX-8 to DSP" drum again, Chike?