[ZeroGSpaceCow]

So, I'm new to Miatas. I just got my first one yesterday, a 1990 5 speed. I'd like to get into Autocross, and would like to keep it in stock class. So, I've got a few general questions that I'm having a hard time finding answers to:

1. The stock wheels are 17s, as I understand it the SCCA requires stock wheel sizes, correct? So I'll need to switch to 14x5.5? Does it matter what kind I get? I was planning on just getting the cheap "five x" wheels from Discount Tire.

2. What tires should I get? I'm having a hard time getting a straight answer on this. Does the SCCA require specific tires, or just not "race tires"? I was planning on getting a set of Falkens from Discount Tire (again cheap, and I don't think I'm a good enough driver yet for tires to make a huge difference to me).

3. What should I do with my old wheels/tires? The wheels are some brand called "Loco" and the tires are Achilles ATR Sport. I know they're not exactly desirable, but the tires have tons of tread and I don't want them to go to waste.

4. As far as I can tell, the SCCA does not require a roll bar for stock class racing, is that correct? This car will also be driven on the street, so is it a good idea for me to avoid a roll bar?

5. Springs/shocks. Let me start by saying I know very little about suspension setups in general, and especially on the Miata. So I really don't know what I should do with the suspension. What should I replace? What's on there is old, and I don't see any bright colors or brand names, so it might be stock, I'm not sure. However, the back end seems to sit higher than the front. It will probably be even more noticeable if I put smaller wheels on. Any suggestions?

6. My "air bag" light is blinking 8 times, which a google search tells me is "poor ground of d-sensor." Does anyone know what that means or how to correct it?

7. The car currently has a Jackson Racing Cold Air Intake. Is this SCCA legal? They say "cone style" CAIs are okay, but this is a flat type, so I'm not sure.


Sorry if these are stupid questions, or if this in the wrong place, but I'm having trouble finding this info by searching. Any advice you guys can give would be great, thanks!


Edit: Oh, and if this helps, this is a second car for me, so it's not necessarily a "daily driver." I got it specifically for taking to the track, but I'd still like to be able to drive it on the street for fun on nice sunny days.

 

[blackdbl9NB]

To answer your questions, SCCA Stock class requires most parts be be OEM or an equivalent replacement part. You can have aftermarket wheels as long as they are the same size as stock, so a 14x5.5 will be fine. As for tires, if you are new to autocross then I would suggest a good street tire to get started. You can run DOT approved race slicks, but as a new driver you want street tires. The reason behind this is the street tires "talk" a lot louder then a slick will. One of the things you will learn to do is listen to the sounds the tires make when you are racing.

As for your old wheels and tires, your options are selling them, keeping them and using them on the street or throwing them away. Personally, I think you can never have enough wheels laying around, so I would hang on to them.

For the roll bar, no you do not need it for autocross.

To stay in the stock class you do not want to change your springs. You can do aftermarket shocks of your choosing. The Koni yellows are really popular in the SCCA stock classes. You can also swap out the front sway bar for an aftermarket bar. Jumping ahead one spot, your intake will kick you out of the stock class. Find a stock airbox, if you are set on staying in the stock class. If you can take one of your wheels off and take a pic of whats behind it, someone on here can probably give you a pretty good idea of whats going on back there. I am guessing there is some kind of aftermarket spring and shock combo though.

As for the airbag light, I am not sure what you have going on there.

 

[ZeroGSpaceCow]

Thank you for the response, that was really helpful.

Would I be better off going to a Pull-a-Part and getting a stock airbox, or should I order a cone-style CAI?

And I think I'm going to go have the wheels/tires switched out today, so I'll take a picture of the suspension while they have the wheels off.

 

[blackdbl9NB]

Well, I'd say check the for classifieds here, once you get enough posts and time in. There are a lot of people that have spare parts laying around. If you have a local yard that has a Miata it wouldn't hurt to pull the parts you need. I do know you need to have the factory intake tube from the MAF to the throttle body, so a CAI is still not going to cut it.

 

[ZeroGSpaceCow]

Oh, okay, I must have misunderstood the rules then. I thought a CAI was okay as long as it had a cone-style filter.

I'm in Atlanta, and we have like three "Pull-a-Part" locations in the metro area that I'm sure are packed full of Miatas. So I shouldn't have any trouble finding a stock box. Maybe the Jackson Intake is worth something and I can make up some of the cost of the new wheels and tires. :|

 

[blackdbl9NB]

Yeah not sure what a used JR intake is going for. Everything before the MAF is wide open, based on the way I interpreted the rules, everything after the MAF needs to be stock.

 

[whitebeau]

Do you still have the stock Steering Wheel with Air Bag in place? If not, the wires that ran to the air bag may not be setup to show a connection.

 

[ZeroGSpaceCow]

Do you still have the stock Steering Wheel with Air Bag in place? If not, the wires that ran to the air bag may not be setup to show a connection.

I'm pretty sure it's the stock steering wheel, but I have no idea if the airbag is there (or how to tell if it is, other than hitting something and seeing if it deploys :lol

 

[ZeroGSpaceCow]

Got the new wheels and tires (cheap Falkens). I forgot to get a pic of the suspension with the wheels off though, but here is a picture with new wheels:

I found a guy with a stock intake, so I'll grabbing that tonight hopefully. I'll also be bleeding the brakes tonight, so I'm crossing my fingers that that will fix it. I think for now I'll have to just deal with whatever shocks are on there, I can't afford to replace them right now (and I'm not sure I'd even notice the difference yet anyway).

 

[blackdbl9NB]

Ooh, looks good man.

One more autocross suggestion for you. Fix the loose nut behind the wheel before you start modding the car. When you get comfortable with the car in its current state, then start making changes, but learn to drive. get lots of seat time, the more the better. If your local clubs offer schools, take them up on it. Get as much seat time as you can.

 

[ZeroGSpaceCow]

Ooh, looks good man.

One more autocross suggestion for you. Fix the loose nut behind the wheel before you start modding the car. When you get comfortable with the car in its current state, then start making changes, but learn to drive. get lots of seat time, the more the better. If your local clubs offer schools, take them up on it. Get as much seat time as you can.

Thanks! My goal right now is to get everything back to stock and in proper working order. I don't want to do any mods because they'll push me out ES class.

As long as I can get my brakes working, I'll be going this Sunday to a local Atlanta Autocross event. They have a Novice program, so that should be really beneficial. Most I'm just really excited to get on a track and have some fun, I'm not really concerned about being "fast" at this point.