Just wanted to let anyone know that is contemplating buying aftermarket wheels for the RX-8 to use for Solo II Stock Class to hold off.

Before I put out $1800 on a new set of SSR Comps I thought I would make sure that it was legal to run them in stock class on the RX-8 without the TPMS sensors installed so I emailed the SEB to get an interpretation on the rules.

To my surprise the response I got back from Doug Gil (Solo Technical Manager) was that he thought that the TPMS sensors were required but was forwarding the question to the SEB as a whole for their consideration.

So for now my suggestion is either wait for the ruling or get in line for an extra set of OEM wheels since no one has any idea of whether an aftermarket wheel can or should be modified to incorporate the sensor.

I feel like I kinda opened a can of worms here but I'd rather find out now that I gotta run heavy wheels instead of at a National event following a protest.

My opinion (not that it counts for much) is that we should be able to run a wheel without the sensor since the only performance advantage over stock is wheel weight which is already free in stock classes.

I run my Miata in CS, Solo II and as far as I know only the same size wheel is required to remain in a stock class. I know there is no reference to TPMS in SCCA 2003 Rule Book. "Vettes also have had TPMS, but I've seen too many with after-market wheels to count!

13.4 states only that the wheels must be the same diameter and width as stock wheels.

The bigger problem may come with the tires that are available for 18"x8", i.e., the tire must have met 13.3 requirements by April 30, 2003; no racing tire; must be available in four sizes and six different sizes. I know some one mentioned Hoosiers, 235/45/18, I think, and they should meet the requirements???

TybeeRX-8 said:

I know there is no reference to TPMS in SCCA 2003 Rule Book. "Vettes also have had TPMS, but I've seen too many with after-market wheels to count!

That's the problem, there is no reference and according to:

"13.1 Authorized Modifications

If a modification is not specifically authorized in this or previous sections of these Rules it is not allowed."

Since it doesn't specifically say you can run without you can't do it. The wheel allowance itself may be irrelevent since we're talking about a sensor and the fact that this may Doom us to OEM wheels may be tough luck!

Quite frankly I was expecting a quick response back that it was okay based upon some previous tech bulletin. The fact that it is going to the SEB for review is disconcerting because it could retroactively affect other cars (i.e. the vette).

Originally posted by Sparky
TybeeRX-8 said:



That's the problem, there is no reference and according to:

"13.1 Authorized Modifications

If a modification is not specifically authorized in this or previous sections of these Rules it is not allowed."

Since it doesn't specifically say you can run without you can't do it. The wheel allowance itself may be irrelevent since we're talking about a sensor and the fact that this may Doom us to OEM wheels may be tough luck!

Quite frankly I was expecting a quick response back that it was okay based upon some previous tech bulletin. The fact that it is going to the SEB for review is disconcerting because it could retroactively affect other cars (i.e. the vette).

IMHO the loss of the TPMS won't be an issue. It does not provide a mechanical function and it not a safety issue for autox. Wheel weight is not an issue, only diameter and width. It will do nothing to enhance (or decrease) the car's performance. But, like you, I'll wait and see what SCCA says since you asked.
But, on second thought, it may produce a constant warning or screw the system up if you (as I'll do) increase tire pressure to 38-40 lbs.