Racing Seat Bracket

8/23/16
I have since removed this bracket and gone to the PCI Sparco Seat Bracket for concerns of not passing tech inspection with my bracket. Info for it can be found here.


A couple weekends ago I went to an SCCA winter autocross event. Doing so I found out two things: A) I need some practice, B) My head with a helmet sits above the roll bar, which you know, defeats the purpose of it. So I spent the whole time in a sort of scrunched position as to not break the rules. After this uncomfortable experience I decided the next piece going into my car are a racing seat and a harness. 

For whatever reason I have always wanted a car with a racing seat and harness. It just makes me feel cool, even though I am sure it makes me look like a tard. Especially when it takes me a couple of minutes to get the harness on and tightened down. But boy do I feel cool. I put in a Sparco Sprint V seat with a G-Force 6 point harness. The seat fits well inside the car. The shoulder support barely sits against the door when it is closed, and the is mostly because my bracket came out a little skewed. 

For those of you taller people out there looking to race a Miata, especially if you put in a hard dog roll bar like mine, you will need a seat change of some sort and you will likely have to ditch the seat rails and go to a fixed mount. I am 6' 0" and as I said, with the OE seat all the way back and reclined, my helmet lies a good bit above the roll bar. A lot of the aftermarket seats come with simple bolt in options that can use the stock rails or supplied rails. The consensus on this seams to be though is it generally raises people up a 0.5". So I was set on getting a seat and making a fixed bracket system for it.

The first part of this was installing the hard dog harness bar. They make a bolt in harness bar for ~$150 for the shoulder straps. When you take the seat belt tower bolts off there are a bunch of spacers on it. The largest space is the same width and the harness bar mount. So remove that spacer then bolt it on. The only problem I have is that it locks up the rotation of the seat belt. This can be fixed by adding some washers to the assembly. 

The part I am most proud of for this seat is the bracket system that my dad and I came up with for it. I planned on re-using the factory seat mounts and the issue with that is if you want the seat right on the floor and all the way back you can't get to the rear bolts to tighten the seat down. So we took a piece of 1/4" steel and bent it to match the rear mounts. This then provides an opening underneath it which I intended to make a tab to slide under it to hold the seat in place. PRESTO,  you know have a seat the only needs the front two bolts to get it in and out. The rest of the bracket was made out of 3/16" thick by 1.25" wide steel plate. The tab that slides in to lock the rear was just a large piece of angle iron that we had sitting around.

When we were messing with placement of the seat we noticed it was getting caught on some bump that was in the back underneath the carpet. So we pulled up the carpet to find out that it was the plug for the narrow band O2. The seat was snagging on it and would go back or down anymore because of it. So I ended up taking it out of its mounting hole and just taping it to the trans tunnel to get me the extra space I needed. Worked like a charm. Just be careful not to yank the wires if you do this. 

Then came the seat bracket. I have a bunch of pictures of it, and next time it is out of the car I am going to take measurements and made a CAD drawing of it for people to use if they want to make something similar. 

The seat mount holes are at an angle and there is a hump behind them. We did some forming using a vice and a big ass pipe to get the pice to go over the hump and lay flat. To get the front cross piece angle I tacked it on each side and put it in the car and hammered it down to fit, then finish welded it.

So the bracket sets in the car and you slide it back to get the angle iron beneath the rear piece. The two hunks of round steel on the back were scrap we had and I welded the on the set the rear height of the seat. There is still some slop in the seat, you can rotate it some before the tab and the rear piece hit. To fix this I am going to take a thick piece of rubber and put a taper on it and glue it to the rear piece to make an interference fit so the seat doesn't move at all. If you go with something like mine, make sure to gusset the angle iron so it doesn't just bend and break at the weld.

I painted the bracket red and slapped it in. The seat is sturdy as can be and is really painless to get in and out of the car. I am really happy with how it turned out. Getting in and out of the car is more difficult now though. At some point I will take a picture of the bracket by itself and add it. 

Pro Car Innovations - Sparco Sprint V Seat Bracket

I somewhat recently purchased the passenger and driver side Sparco seat brackets from FRSport for the miata. I never felt like the bracket that I made was good enough to pass a real safety inspection as the seat could rotate just a little before the rear 'latch' hit the cross piece. So rather than design and make a new one, I went the lazy route on this. The PCI brackets looked well made and most importantly looked like it would get my seat low while still using the factory mounting locations. The only thing that you have to do for these brackets is, on the driver side only, hammer the trans tunnel in to make clearance. If you look at my post about the bracket I made, I had to do this also. This bracket requires more 'messaging' of the tunnel than what I originally did. But it was easy and I had no problems with a big hammer and a little patience.

I am happy to report that the bracket does keep me really low. I really don't think I can get my seat any lower without having to cut out the factory mounts and make my own. At which point I would still need space for the submarine belt mounts, so I could maybe get another 0.5". The adjustments on the side are also enough that I can get the bracket to work both for me and the lady friend (well close enough for her, we have to bolster her forward just a little extra so she can push the clutch in all the way). But considering I am 6'0" and she is 5'5" (This is a guess), the bracket offers a lot of adjustment.

I am writing this blog entry to show some tricks I have found on getting the seat in and out of the car. If you are short and have the seat mounted forward on the bracket, then it is very easy to bolt the seat to the bracket. Then put the whole assembly in the car and bolt the bracket to the car. But if you run the seat far enough back, like I do, you run into the problem of getting the rear bolts for the bracket in. Well then you have the option of bolting the bracket to the car then dropping the seat in and putting the side bolts in. This would be fine if there was some GOD DAMN clearance between things! You can make it happen but it is slow and frustrating. So below is what what I have found to work the best for getting the seat in and out. I can take the seat out and have it put back in under 5 minutes this way.

Step 1: Start with putting the two front side bolts in. Keep them loose enough that you can rotate the seat around them.

You need to be able to rotate the seat like this.

Step 2: If you have one, get the harness pieces out of the way.

Step 3: Bolt down the front of the bracket. You can make these tight.

Step 4: Rotate the seat up as far as you can.

Step 5: With the seat rotated up, you should be able to reach back in there and get the two rear bolts in and tight.

Step 6: It is still a little frustrating, but now put the two rear side bolts in. I find it easiest to use a ratcheting wrench to help make things go quickly. Tighten down all of the side bolts and you are good to go!

Easy as that everyone. Once you do this a couple of times, you will be able to get the thing in and out if needed in no time at all. Now time for TRACK DAY BRO!

Nothing like a track day with your bro's, even if your car is the slowest one down the straight