Cheap, Effective Seat Bolster For Racing?

Does anyone have any tips, short of buying a full racing seat, to help keep the shoulders and torso stable during high speed braking and cornering?

I am noticing that as I upgrade the tires and suspension on my trusty little MX5, the next limit I am running into is my inability to keep myself in a proper driving position due to G-forces. And since this is also my daily driver, I'm looking for cheaper solutions that I can try before I take on the hassle and expense of a racing seat. For instance, I know that some of the autox drivers use the seatbelt trick? Involves some device that goes on the seat belt that locks the seatbelt in place? I wouldn't know where to get something like that. If it wasn't for the fire hazard, I'd have someone duct tape my chest to the seat. See where I'm going here? LOL. Help!!

which generation MX5? A popular budget mod on the 1st gen (maybe 2nd gen too) is a Foamectomy. basically involves trimming or completely removing the center foam pad in the seat. more involved foamectomies even start trimming the bottom cushion of the seat.

http://www.miata.net/garage/foamectomy/

as for locking the seatbelt, pull it really tight, then give it a good yank to engage the built in locking mechanism. I assume this is what other drivers are doing.

Do you have a rollbar? I used a 5-point harness (with 4 points attached) for a bit with a stock seat.

Here is the website for the CG Lock:

http://www.cg-lock.com/

The seatbelt device you're thinking of is probably the CG lock. It's a manual mechanical lock that will hold you in a bit tighter than the seatbelt's own locking mechanisms. (Edit: D'oh, beaten.)

For the seat, you can look at pulling the fabric off and inserting more foam, or welding in metal bolsters beneath the foam if the seat doesn't already have them (don't know if a Miata does or not).

Non-slip drawer liner? Just drape it over the seat back and sit down carefully.

Miata seat backs are molded with the frame in the mold. You can't remove the foam readily and weld on extra bits. You can do that to the seat cushion (I have in my Miata) and get some thigh support.For the back you could try removing the foam insert in the middle. That will allow you to drop into the back further, effectively increasing the height of the side bolster.

Just do a race seat. A well fitting one will be more comfortable than the stock seat anyways, just more difficult to get in and out of the car with the top up.

CG lock or a 4 point harness. Mount the harness but leave your regular seat belt for DD use. I used the seatbelt lock thing that came with my kids' car seat since we had latch in all of our cars anyway.

The brass colored thing below:

::cough cough:: Been said already, n/m.

The only problem with the CG Lock is that it only locks the lap belt. It's super-easy, though. I ran one for years.

When we're running our open house track days, I'll be jumping from car to car. Most of them have standard seat belts. I pull the belt tight with the end about 2" from the latch, jerk it to lock the inertial reel, then ram myself back into the seat with my leg and latch the belt. Do it right, and it's TIGHT on both the lap and shoulder belt. It'll hold me in place when I'm driving a V8 Miata on hot race rubber on a kart track.

DeadSkunk wrote: Miata seat backs are molded with the frame in the mold. You can't remove the foam readily and weld on extra bits. You can do that to the seat cushion (I have in my Miata) and get some thigh support.For the back you could try removing the foam insert in the middle. That will allow you to drop into the back further, effectively increasing the height of the side bolster.

Dont do this unless you want a metal bar in your back that creates a pressure sore. Ask me how I know.

In reply to Keith Tanner:

Yeah I did similar in my VW's. Slide the seat back a couple or 3 inches. Lock the inertia real as tight as I can then slide the seat forward to it's usual position. I could get it tight enough that it was uncomfortable until I dropped the clutch...

I ran a Schroth Rallye 3 harnessbelt for quite a while happily on the street. I got used to shrugging into both sides pretty quickly, and it was nice and secure for autocrosses. Not sure whether there's a Miata fitment, but would think so.

I was also running a pretty well bolstered Scat seat, but it's clear the Schroth helped.

That said, I'm a big fan of properly bolstered seats. If at all possible try them out. I had a Corbeau that I liked pretty well, but it was just a touch wide, and left me to rock back and forth a skosh, with just a standard 3-point belt.

DeadSkunk wrote: Miata seat backs are molded with the frame in the mold. You can't remove the foam readily and weld on extra bits. You can do that to the seat cushion (I have in my Miata) and get some thigh support.For the back you could try removing the foam insert in the middle. That will allow you to drop into the back further, effectively increasing the height of the side bolster.

Maybe I am just slow but why can't you just trim some foam off the back with a turkey carver then spray glue some bigger chunks on?

Keith Tanner wrote: The only problem with the CG Lock is that it only locks the lap belt. It's super-easy, though. I ran one for years. When we're running our open house track days, I'll be jumping from car to car. Most of them have standard seat belts. I pull the belt tight with the end about 2" from the latch, jerk it to lock the inertial reel, then ram myself back into the seat with my leg and latch the belt. Do it right, and it's TIGHT on both the lap and shoulder belt. It'll hold me in place when I'm driving a V8 Miata on hot race rubber on a kart track.

Nice idea on the shoulder belt, I have had a cg lock for years but never tried that.

The cg lock is worth a shot, with my nx everyone always complains about how uncomfortable the seats are and swap foam from the ser . I gave the cg lock a chance, push back into the seat and crank her down. Being pressed back into the foam makes the seat more tolerable to sit in and kind of has a bolstering effect. I guess if it works or not depends on a million other factors but might work for you

jere wrote:

DeadSkunk wrote: Miata seat backs are molded with the frame in the mold. You can't remove the foam readily and weld on extra bits. You can do that to the seat cushion (I have in my Miata) and get some thigh support.For the back you could try removing the foam insert in the middle. That will allow you to drop into the back further, effectively increasing the height of the side bolster.

Maybe I am just slow but why can't you just trim some foam off the back with a turkey carver then spray glue some bigger chunks on?

You can certainly do that. I was referring to welding on extra steel support for larger bolsters. Back foam is normally much softer than cushion foam and may, or may not offer a solid base to glue more bolster foam to.It certainly wouldn't hurt to try it. The hardest part would be sewing some extra vinyl into the cover. I've played around with my Miata seats so much that I finally gave up. I now use a standard NA back because they have the most pronounced side bolsters and my cushion foam is actually from an old VW GTI.

If you're pulling foam out of the Miata seats, leave most of the center pad in place. You can make them very comfortable and with decent bolsters.

By the time you get to welding extra steel inside, you might was well just start with a new seat.

Keith Tanner wrote: When we're running our open house track days, I'll be jumping from car to car. Most of them have standard seat belts. I pull the belt tight with the end about 2" from the latch, jerk it to lock the inertial reel, then ram myself back into the seat with my leg and latch the belt. Do it right, and it's TIGHT on both the lap and shoulder belt. It'll hold me in place when I'm driving a V8 Miata on hot race rubber on a kart track.

I tried this today, it works but it takes some practice to learn the technique to get just the right amount of slack. Too much and the seatbelt unlocks, too little and it won't reach the latch. You need to only hold the belt by the buckle and if you're doing it right, it feels like you're stretching the belt to get it latched. I'll try this next time I'm autocrossing.