Learn Me Race Seats and Harnesses

I will be looking for a budget set of seats for my MR2 project. It is a street legal rallycross and autocross car. I would like to know what to look for in seats and harnesses for it. I'm not a thin guy clocking in at a 40" waist so I would like bolstering but not too tight. The car will also be driven by others so I will need sliders and wouldn't hate if the seats recline but that may be out of budget. The seats also need to be at least livable for 2 hour drives to events. I need to know how custom seats are installed how most people create the brackets to attach them to the car.

For the harness I will likely be installing a rollover hoop along the back firewall and placing a bar across to attach the belts to. I'm doing this for safety obviously but also because I hear that bolting harnesses to the floor is an excellent way to break collar bones. For the harness I prefer the idea of a 4 point over a 5 point harness for comfort while driving. I have read that 4 point harnesses are frowned upon because of the possibility of submarining but it seems like that same issue can happen with the standard seatbelts. I'm mostly looking for a way to keep myself in place on a rallycross course and also becuz racecar.

Honestly, it's getting more and more rare to find places that even allow 4pt harnesses. Believe it or not, but a 3pt protects you better from submarine better, as your torso can twist forward enough to keep you in place. 4pt eliminates that motion and only way to go is sliding down. The more you recline the seat, the worse the effect. I'd recommend either stick with the 3pt or get a 5/6pt.

Can't run a 5 or 6 pt with factory seats, but the narrow wells do limit your seat choices. For instance, corbeau fx1 pro will fit, but the standard fx1 won't, and it's only 2" wider.

Nice thing is shoulder straps are easy, due to the back wall. its all about getting the right angles, reading the install manuals will give you a good understanding, and the good harness manufacturers all have then online.

Ahh I was wondering if I could go thru the firewall to install the shoulder belts since I expect it would be reasonably strong. Twisting to not submarine makes sense and I can see how the standard belts would be better although I would think twisting like that brings its own set of issues in a collision.

I haven't done a close examination of mine, but with a proper backing plate you should be able to use the firewall without a problem. Plan to do the same for your lap and crotch straps too using a good backing plate. However if you're going to be running a good roll bar, with integrated harness bar, then it's a moot point. Just keep it back far enough that it's nowhere near your head, and I'd wrap everything shoulder level and above with FIA compliant padding. Bare head impacting a bare roll bar/cage = high probability of death.

Either way, if you run a harness you'll really want to also leave your 3pt belt in place too. A harness will hold you in the seat TOO well for normal street driving. Use the factory belts on the street.

Based on what you've said I'll probably just scratch the harness and look into some seats. Anyone with input on installing them? I'm a bit worried about creating the brackets, what kind of materiel to use to fabricate them, what are mistakes people make? I also hadn't really considered width until hhaase brought it up so I'll have to do some measuring.

I have 5-points in the Manic Miata, with Corbeau FX-1 Pros (I think they Pros are wider, but I could be mistaken - I have the wider ones). The crotch belt is not uncomfortable at all and is easy to hook up. I drive the car in the street fairly frequently during nice weather. Honestly, the thing that would bother me after an hour or two is the e-brake handle, NOT the seat or belts. It does have a beefy rollbar with FIA padding, plus a harness bar.

https://www.schrothracing.com/products/rallye-belts

Submarining is more likely Because the shoulder straps on harnesses are essentially pushing you down in the seats unlike stock 3 point belts. Also the crotch strap keeps the lap belt from climbing when You cinch the shoulder belts.

You didn't mention seats but on a budget I'd recommend the ultrashield rally sport. Nice shoulder support and comes in widths up to 18" which should be plenty wide. Maybe even a 17 would fit you. Abot $280,

The $ 400 price is more attractive than more than twice that for an FIA plastic seat. But how do you brace the back of those things?

JBasham wrote: The $ 400 price is more attractive than more than twice that for an FIA plastic seat. But how do you brace the back of those things?

http://www.ioportracing.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=SBB2&Category_Code=IH

Google is amazing.

Here is some harness install info from your friends at GRM.

z31maniac wrote:

JBasham wrote: The $ 400 price is more attractive than more than twice that for an FIA plastic seat. But how do you brace the back of those things?

http://www.ioportracing.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=SBB2&Category_Code=IH Google is amazing.

That looks like a cool solution. Is it the one you use? Do you like it?

Does everybody use something similar? And so I need to think of this $400 seat as a $500 seat because it needs a $100 back brace?

Thanks in advance to the hive.

JBasham wrote:

z31maniac wrote:

JBasham wrote: The $ 400 price is more attractive than more than twice that for an FIA plastic seat. But how do you brace the back of those things?

http://www.ioportracing.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=SBB2&Category_Code=IH Google is amazing.

That looks like a cool solution. Is it the one you use? Do you like it? Does everybody use something similar? And so I need to think of this $400 seat as a $500 seat because it needs a $100 back brace? Thanks in advance to the hive.

It only needs to be a $500 seat if you require the back brace. They're only needed for track days. Granted, they're a good idea on the street too, but not as critical as, say, roll bar padding and a low enough seat to not crack your noggin.

Thanks! Yes, this is for track days. I have to figure out if the club rules require a certified part somebody else made and sold me, or if there are alternatives for the home fabricator. The LeMons guys seem to DIY.