i currently race in a bs class but i am thinking of going to stx. what all aftermarket items could i put on my 05 rx8 that would still keep me in stx?

 

Your car isn't eligible for STX. The street tire class it is eligible for is STU. Similar ruleset to STX but a different group of cars.

The list of modifications you are allowed is on the scca's website. Specifically:

http://www.scca.org/_FileLibrary/Fil...solo_rules.pdf

Search for STX and then review the STU supplemental rules here:

http://www.scca.com/_FileLibrary/Fil...talclasses.pdf

 

Essentially, STU can do everything in STS and STX. The difference being an RX8 can run ANY wheel width and 275s vs 245s for AWD cars.

Biggest things that will kick you out of STU is removal of *all* catalytic converters (you must retain one, even it's a high-flow unit... and I'm not even sure if the RX8 has more than one), clutch, flywheel, tires wider than 275. There are a host of other things that you can do to get put in a higher prep level.

ECU is essentially free for RX8s as long as its programmed in the standard housing.

If I were running STU, I do something like this:
Decent coilovers
Maybe even camberplates for easier adjustment of camber in the front.
Front/rear adjustable sway bars for fine tuning
Better bushings
Better exhaust (lighter) with highflow cat
Seats, both pass and driver (lighter the better... but make sure that with mounting brackets they're 25lbs due to rule change possibly next year)
I think the shifter in the 8 is decent, but a shorter throw never hurts
I also think the LSD in the 8 is good, but there may be better choices out there to replace the stock one.
Lightweight wide wheels (around 9.5-10")
275 tires all around
But before all that.. http://www.autocross.com/evolution

--kC

 

I especially agree with the last one. I haven't been to Evolution, but the local SCCA Autox school was excellent, and the seat time alone was invaluable.

Also, if you don't want the expense of going with coil-overs, I've had very good results with using Tokico D-Spec adjustable shocks with stock springs. Even on track days, I've gone through the twisties a hell of a lot faster than I ever could before.

 

You'll never build a competitive STU car with the stock springs. Higher rate springs on adjustable perches will offer you much greater control over body motion and weight transfer, a lower Cg, and will give you much needed additional front camber in order to better utilize your tires.

 

How are camber plates gonna help you when the geometry is set by the upper and lower a-arms? This ain't no Subie .

The '8 has one big long catalytic converter. It is very heavy. I'm sure Sipe has the weight of the manifold and catalytic converter pipe in his STU thread.

John

 

Dumb

 

which of course is great, but tuning ECU options are, uh, rather scarce. poop.

255/40-17 (17x9") or 265/35-18 (18x9.5") are best for grip vs. gearing. those with fancy schmancy data acquisition devices feel free to prove me wrong. :-D

 

Yeah... oops. Brain dead. 4 meetings today, and a job order change for a product thats due next week.

--kC

 

it's just around the corner for public purchase on all model years