Autocross and track mods

Hi Friends!

As you know, I just got into the miata game with my new 95M. The car is bone stock, but I want to start preparing it for autocross and track in the future. I know there are several categories and brackets that I can fall into based on the mods. I've looked around and have a couple of specific issues that I would like advice on. I am a tall dude, 6'4". I have stock seats but I plan on doing a little foamectomy to gain some room. My question has to do with roll bars. Ideally I'd like a set that sits behind my head, since every miata I have sat in I hit the bar. Obviously this would be worse with a helmet. I'd like to see what kind of rules I need to meet when it comes to prepping the car for auto x and track days. Does my helmet have to be below the roll bar? I like the deuce set up for roll bars so I don't have to sit underneith them, but I'm not sure if that will fly with regulations. Am I screwed because of my height? I'd like to participate in as many races and events possible, so a set up that meets the stricter regulations might be the best. Please let me know your thoughts. Thanks everyone!

Also, who's going to the next event, I think it's the bmw one in April.

J, at 6'4", you're going to have a hard time passing the 'broom-stick test' regardless of the bar. The Deuce does sit the farthest back, but that also flattens the imaginary line from windshield-header-to-rollbar. Start with a foamectomy, and see where you end up. IIRC, the '95M seats are shorter (closer to floor) than regular NA seats.

PS
Here's the AX calendar - http://www.dfwmiata.com/content/3-autocross-calendar

PPS
Seat time, seat time, seat time.

Biggest issue for the guys making the roll-bars is if you want to keep your convertible top they have some height contrasts to deal with if you want to close the top.

Decent chart showing rough dimensions - http://www.bethania-garage.com/guide.htm

I also agree with Sammmm - Seat Time - Seat Time - Seat time! (The car is already faster than you.) ;-)

The biggest issue with needing to fit below the roll bar is if you have a harness holding you up. If your head is above the roll bar and your hardness is holding you there, then you're toast if you invert. Same without a roll bar, but with a harness. However, if you just using your normal seat belt, then your body can potentially bend out of the way, with or without a roll bar. Just not have to bend as much (and possibly less lethally) with the roll bar.

I've not run into any issues with my roll bar height at events because I do not have a harness.

Ok, cool. I have been advised not to cut up the m seats, anyone have any old leather seats they are discarding or for sale?

^Cloth seats are 'stickier' (and probably cheaper) than leather. If I was going to replace seats, I'd go cloth.

Ok, anyone got a crappy cloth seat they are getting rid of?

You do not need any roll bar for autox. Unless you plan to track the car significantly at some point, I wouldn't bother with a roll bar at all, since your height adds a significant head-injury risk in a typical collision. Miatas CAN roll, but it is exceedingly rare, even in track situations.

You can remove the foam from your M-edition seat bottom and save it without damaging the integrity of the original seat, then chop up the foam bottom from another old seat. I think I've got one you can have for $25. Much better than mismatched seats.

You might make plans to attend the TDR Swap meet this Saturday to search for parts/accessories/seats for your new toy, then go to the ER autocross on Sunday at LSP for some seat time.

It seems like someone is always selling NA cloth seats on CL.

Quote:

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Originally Posted by OZMDD

You can remove the foam from your M-edition seat bottom and save it without damaging the integrity of the original seat, then chop up the foam bottom from another old seat. I think I've got one you can have for $25. Much better than mismatched seats.

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I think the seat bottom (and foam) in a '95M is different than other NA's. Anyone know for sure?

Yes, very different…

If you're looking to track the car ....
The Hard Dog 'Hard Top' bars sit further back than the non-Hard Top. It's best to get a seat that's tall enough so there's always seat between your head and the bar. The Hard-Core versions are acceptable by all the organizations, except BMW.

At 6'4" you may want to look at an entirely different seating option. I have a set of these, they get as low as any seat with rails. http://www.good-win-racing.com/Mazda...t/61-1084.html
My plan is to sell then sometime late spring/early summer, when I can afford a race seat. They'd be OK for short daily driving, but they're not great for 8 1/2 hour trips.

The other option is to drop the floor pan and bolt a race seat to the floor. Here are the two kits I know of:
http://www.advanced-autosports.com/i...roducts_id=694
http://mazdaracers.com/store/product...or-drop-panel/

We tell every eager new Miata owner that wants to autocross/track their car the same thing.
Make sure your car is safe, change the fluids, inspect the brakes, maybe get some sticky tires and an alignment.
Then....
Before you do anything else....
Drive your car for the rest of the year at as many events as you can and attend any schools you can.
Decide what your goal is for you and your car...
and then..
and only then...
start modding your car.


(Most of use didn't listen either...) ;)

Quote:

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Originally Posted by wrx74

We tell every eager new Miata owner that wants to autocross/track their car the same thing.
Make sure your car is safe, change the fluids, inspect the brakes, maybe get some sticky tires and an alignment.
Then....
Before you do anything else....
Drive your car for the rest of the year at as many events as you can and attend any schools you can.
Decide what your goal is for you and your car...
and then..
and only then...
start modding your car.


(Most of use didn't listen either...) ;)

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^Very Wise Words! :clap:

Thanks everyone! Eric J, keep me in the loop on that seat. If you go to an event I'd like to check it out!

I am 6'5" and just pass the broomstick test (top of helmet 1" below board from windshield to roll bar) using a roll bar that fits under a hardtop (but wont work with a soft top) using a race seat with no cushion that is hard mounted on the floor with the seat humps removed. It also required leaning the seat back quite a bit. I will have the car at the ER event this Sunday if you would like to see.

As a note, my 5'6" wife did not pass the broomstick test in a stock seat. Miatas are so small.....

Testing varies. BMW 'broomstick' test is from the rollbar to the front upper suspension mount.
The windshield will collapse in a roll over.