Question about STX - boost level
 

OK so silly question. I have the RMW tune and love it. I also autocross my car and have been running in D Street Prepared FWD which is a killer for PAX. I assume I need to be in this class because it allows one to increase boot levels via ecu tuning whereas STX class does not. Question is if I have the stock intercooler should I really be running in STX?

You should be running in DSP with the aftermarket tune that increases boost. Does your region have a road tire multipler so that you could run "DSP Road Tire"?

Why not spend the $500 and get a custom tune done that is STX legal?

I guess I didn't know I could...well actually I didn't realize the boost increase was not legal in STX when I had it done.

Well boost increases in STX are the same as STU. Which is to say they're a little tricky. You cannot directly alter the boost levels via ECU reprogramming which is what your tune is doing. However, any increases in boost that happen as a result of a different allowed modification (downpipe replacement for example) are allowed. What this means is that many of the built to the letter of the rules STIs and EVOs are running modified downpipes which essentially cause boost spikes allowing them to run higher boost levels while staying within the letter of the rules.

For your purposes you really have 3 options:
1. Run in DSP where your car currently belongs
2. Get another map done which is STX legal
3. Run in STX locally and don't worry about it

I personally would choose option 3 depending on your driver level. If you're just out there to have fun and want to run at the same time as the other STX guys I doubt anybody is going to protest at a local level. If you're beating all of them then you should definitely be running DSP or getting a custom tune done. You could even walk around grid and ask if anybody has an issue with it.

Well said. I feel like I should be in DSP because I don't want to feel like I'm cheating the rules however I am just out to have fun at this point and not running for any kind of national trophy. Jan from RMW is in my town this weekend and I'll see if he has a tune that would be considered STX legal. The problem with DSP is that I'm essentially in my own class (running street tires) and on an index against the other FWD street tire guys. Running STX would allow for a bit more competition. Oh and this is only my second year autocrossing. Right now I'm thinking about making the Mini a track car and getting something else dedicated for autocross. Of course I guess I could still track an STX Mini.

Well there is always the counterpoint of "if you're just out there to have fun why don't you just run in the class that your cars falls in".

You can track an STX mini but it's not without it's drawbacks. It really depends on how serious you get with auto-x. The car setup required to get a mini to rotate at 40mph would be quite difficult to drive at 110mph. The car would want to spin on every corner entry. If you're just out there to have fun you can do a compromise setup that will understeer a little at auto-x but drive great on the track. All depends on what you want.

That's kind of what I'm thinking as well and don't want to bend the rules. Thanks for the input on the STX car. Basically, this car will become a dedicated track machine I think. Looking at getting into a Miata or perhaps a Civic next year for autox and try to be somewhat competitive. In other words I'd like to get more serious about it but know I can't with the way I currently have the Mini set up.

If you're looking to be really competitive in auto-x you kind of have to pick a class you want to run in and then sit down and do the calculations for the cars in the class to see what you think would be most competitive. The mistake people make is buying a car because they "like" it. If you really want to be competitive you can't really be too picky about which car it is.

There are a few low cost ways to get into a competitive auto-x car. Be careful buying a competitive Stock class car because the SCCA is going to have a huge stock class rule change-up in 2014 that will really change things. I would recommend the Street touring categories. An 89 Civic for STS or an E36 3-series for STX are both pretty low cost. Keep in mind though that building a national level one of either is still going to cost 10-15k.

A couple of years ago I did that and bought an NB Miata, never having autocrossed. It was a fantastic car but completely outgunned (not to mention the driver) in c stock. Now I hear they're moving the NB to e stock along with the BRZ/FRS. So I'm kind of looking that way. The Civic or a CRX would be nice as well and yes I would agree that the ST classes are not a bad way to go. I've also considered potentially running an NC Miata in c stock/STR. Not looking for anytihng national at this point. I'm not that good and still new to the sport.