15 replies to this topic

[Andrew Stowell]

I'm replacing my UltraShield Spec Miata seat with a Kirkey 71 Series seat and I'm not sure how to mount it. The current seat is bolted to the floor somehow ( can't see how until I remove it), and has a steel back brace that goes to the harness bar.

 

So Kirkey wants me to use these mounts:

https://www.kirkeyra...-71-SERIES-SEAT

 

And this back brace:

https://www.kirkeyra...OR-70-71-SERIES

 

But I don't think the mounts will work in a miata and I have no idea how that back brace is suppose to attach to my harness bar.

 

I would prefer to bolt the seat to the floor and use this back brace instead:

http://www.ioportrac...ategory_Code=IH

 

I know this is a common seat for spec miata, so I'd like to know how everyone recommends mounting it. Pictures would be great.

[Steve Scheifler]

No reason the side mounts wouldn't work the same as with many composite seats, why do you think it would not? Overall width maybe? In our case however we still bolt directly to the floor as we did with the simpler aluminum seats. I'm not aware of a reason not to do that but someone likely will .

Their back mount is pre-bent and drilled to match the seat but would require something like a horizontal "shelf" welded or attached to the cage bar, with the back mount bolted to that. The (expensive) adjustable one from ioport is nice but heavy if you don't need the adjustments and may require some work as well to mount properly to the seat back.

[BlueJay73]

I have that seat in my car.

I bought the Kirkey mounts, but found them difficult to use, so mine is bolted directly to the floor.

I bought the Kirkey back brace, but found that difficult to use, so I used the IO Port back brace. I had to bend the flat part of the brace to fit the contour of the back of the Kirkey seat. That was really easy. Took 5 minutes.

[Andrew Stowell]

Steve- I wasn't sure if the mounts would be too wide, or move the seat too high. My head is close to the roof with the seat on the floor, so loosing a couple inches isn't great. Kirkey says you need to use the mounts, so I wanted to make sure it was safe not to.

 

BlueJay73- Good to hear it worked for you. I already have a IO Port brace sitting around that is suppose to go in my ChumpCar. So my plan was to use it if I don't have something else when I'm ready to mount the seat and buy another one for the other car later.

 

If I just bolt it to the floor, how do I have room for the anti-submarine belts to mount? Do I need spacers for the front of the seat or something?

 

I'm thinking about using this back brace:

http://www.jegs.com/.../70291/10002/-1

 

And a couple of these clamps instead of welding tabs:

http://www.jegs.com/.../10802/10002/-1

 

Does that sound safe?

[BlueJay73]

Good question regarding the anti-sub belts.

The Kirkey seat bottom is not flat, but has two planes. About 2/3's of the bottom toward the rear is where I bolted the seat down. I used stacked washers in the place or two where the Miata floor was not flat and did not meet the seat bottom flush.

The 1/3 of the seat bottom towards the front is angled up a little. I bolted the two eyebolts for the 6 point anti-sub belts under the angled part of the seat bottom. (I wish I had just gotten a 5 point harness with one anti-sub eyebolt/belt; much easier to mount.) These eyebolts under the slightly inclined part of the seat are not easy to mount or get to. That would be much easier with the seat mounts.

I have plenty of headroom with the seat on the floor; would have at least an inch or two less if I had used the mounts.

If I could have made the mounts work, I'd rather do that; but I was not happy with my result, so I went directly on the floor. Other than the inaccessibility of the eyebolts, it works fine.

 

Jim

[swegian]

Andrew - how tall are you and what width Kirkey seat are you installing? I plan to install a Kirkey 47 series in a 2001 Miata for street/HPDE use. I am 6'1" and 185, and will probably use the 16" width. Hopefully, no modification of the transmission tunnel is needed.

 

Thanks,

 

Jim

[Bench Racer]

Comment only:

 

With the carpet out the tunnel can be massaged with a body shop axial impact gun with a mushroom head tool. My (6 ft/210 lbs) SM has a 16 inch Ultra Shield Pro road race seat and I was able to push/reform/reshape the tunnel so I could flat floor mount the seat. I removed the rear OEM seat mounting humps, left the forward seat mount/floor re-enforcement in place and modified the front bottom of seat. 

[Jim Drago]

Comment only:

 

With the carpet out the tunnel can be massaged with a body shop axial impact gun with a mushroom head tool.

Or what most others use.. a BFH

[Andrew Stowell]

Andrew - how tall are you and what width Kirkey seat are you installing? I plan to install a Kirkey 47 series in a 2001 Miata for street/HPDE use. I am 6'1" and 185, and will probably use the 16" width. Hopefully, no modification of the transmission tunnel is needed.

 

Thanks,

 

Jim

I am 6' and about 180 lb. I also am getting a 16" seat. There is a 18" UltraShield seat in the car from the previous owner, so I'm hoping the new seat will drop in. Not sure if the tunnel was modified to fit the old seat in.

 

BlueJay73 -  Thanks for explaining in more detail. I think I get it now. I got a chance to look under the old seat and the front has spacers I should be able to reuse and the rear is right on the floor.

[Jim Drago]

Andrew

These are more and I hate pimping my own products. But these are INFINITELY more adjustable and a far better solution. Once you bolt this bracket to the floor, you can move it forward and back in 3/4 in increments without drilling holes and Swiss cheesing the floor. Once the seat is mounted, there is a 2.5 in slot on the side that allows you to fine tune your seat adjustment without un bolting. 1/2 in in seat position feels like a mile. 

 

http://mazdaracers.c...m-seat-bracket/

[BlueJay73]

Yeah, I wish I had gotten (known about) those brackets. They look like what I was wishing for while I was Swiss cheesing my floor.

I think those brackets are the way to go.

[Jim Drago]

Yeah, I wish I had gotten (known about) those brackets. They look like what I was wishing for while I was Swiss cheesing my floor.

I think those brackets are the way to go.

That is why we had them made. we had swiss cheesed a few floors in our day with missing on first attempt, changing seats,drivers etc. It is frustrating 

Jim

[Sphinx]

I've got this funky bracket that I think Bret DePedro fabbed.  It uses the front OEM holes but then the rear humps were removed.  It has three adjustment holes and it bolts directly to the bottom of a Momo Start.  

 

I'm switching to a side mount and am wondering if the best way is to 1) remove the front humps and bolt straight to the floor or 2) buy a square piece of iron and fab it to work with Jim's brackets (which I have) and the existing humps.  I know that choice #1 is easiest, but I don't have the right tools to do this right.  2) I think I can do with a bit of elbow grease....

 

My initial desire was to mount the whole thing on sliders and anger the tech gods.....

[Bruce McKee]

Joe, Do you happen to have any photos of your bracket installed?

[Bench Racer]

pm site member Michael Novak, he designed a very ingenious seat back brace for his new T4 car last year. As I recall very economical and easy to build. I'd tell you more but memory blank.

[Andrew Stowell]

I ended up using the Jegs back brace with some 3/4" square tubing and u bolts. Really solid compared to my old setup. The seat is bolted to the floor with six 7/16" grade 8 bolts and 1/8" backing plates. Rock solid setup.