71 replies to this topic

[David S.]

Hello all,

I am currently in the process of building my first Miata and looking for ideas on how to mount the seats. My dad will be welding in the MiataCage in January and we will mount the seats at the same time. I just want to see what other people have done for getting everything mounted in before we get started. I am most likely going to be getting the Kirkey Intermediat road race seat. I went to OG Racing to sit in some seats and found it the most comfortable and was really happy when I saw the price. They told me that most people put it directly on the floor, drill four holes through the seat and floor board, and then bolt it down. I am assuming that removing the stock "humps" is neccessary for this. I have two concerns with this. 1- I am not very tall so it will probably be too low for me. 2- How would you go about mounting the sub-marine belt if the seat is on the floor? I really want to put my seat on a slider in case anybody else drives it (which will be abnoxious with the seat back brace), but the passenger seat I am fine with bolting it to the floor if I can figure out how to mount the belts. Anybody have any tips or pictures of what they used?

Thanks,

David

[FTodaro]

I am 5'11", and I built a frame that bolted, to the stock mounting points. If you mount to the floor, I would not be concerned about being to low, the lower the better.

If you mount to the floor, you still should have room for the belts, but maybe someone can comment on how they did it.

jim Drago, a vender in the Classified sells a floor pan insert, that you can weld in the gives you extra room to install a larger seat.

[RussMcB]

I will be buying and installing a seat soon, too, in my '99 (and first) SM. I'll be watching this thread for any good advice posted. I do plan to use the Drago trans tunnel cut-out. I'm 6', 170 lb.

Thanks, guys.

[Keith Novak]

We tried mounting mine to the floor but the position wasn't good for me (6'). We then welded the humps back on and installed some 3" x 3/16 flatstock bolted to the original seat mounting holes. Cardboard templates make it easy to locate the bends and the hole locations. Set the seat on them, find your position, mark the holes through the seat (easiest with 2 people) and drill. Tack weld the nuts on the bottom of the flat stock to make mounting easy. One of the sub bolts is bolted directly to the floor with a big washer on the back side. The other is a G-force eye bolt with a detachable connector so you can install the seat, snake the belt through the seat hole and snap in the other side. I have a bunch of pictures on the old site but can't find them at the moment.

[Michael Novak]

I will get some pictures of my setup. I have kerkey that uses the stock front mounts and then we cut the bottom of the set out and modified the seat to then bolt flat onto the floor. It will make more sense with pictures

[FTodaro]

There is a vender that sells a sweet set up that bolts to the stock points, I will try and find it post it.

[Killian]

There is a vender that sells a sweet set up that bolts to the stock points, I will try and find it post it.

http://www.good-win-...tml?id=5z9iSPNG

???

[David S.]

I am 5'11", and I built a frame that bolted, to the stock mounting points. If you mount to the floor, I would not be concerned about being to low, the lower the better.

If you mount to the floor, you still should have room for the belts, but maybe someone can comment on how they did it.

jim Drago, a vender in the Classified sells a floor pan insert, that you can weld in the gives you extra room to install a larger seat.

Thanks! I guess everything will be more clear once I have the seats here. As for being low, I have no doubt that it helps but I feel like there will be a lot of other factors keeping me from winning for now so I might as well be able to see over the steering wheel until they are all fixed. LOL!

[David S.]

I will be buying and installing a seat soon, too, in my '99 (and first) SM. I'll be watching this thread for any good advice posted. I do plan to use the Drago trans tunnel cut-out. I'm 6', 170 lb.

Thanks, guys.

I will be sure to post in here with what I end up doing. I hope there will be a lot of examples in here because throughout my research I didn't find much and everything I did find was one setup per thread. Good luck with your build!

[David S.]

Just discovered the MultiQuote option

We tried mounting mine to the floor but the position wasn't good for me (6'). We then welded the humps back on and installed some 3" x 3/16 flatstock bolted to the original seat mounting holes. Cardboard templates make it easy to locate the bends and the hole locations. Set the seat on them, find your position, mark the holes through the seat (easiest with 2 people) and drill. Tack weld the nuts on the bottom of the flat stock to make mounting easy. One of the sub bolts is bolted directly to the floor with a big washer on the back side. The other is a G-force eye bolt with a detachable connector so you can install the seat, snake the belt through the seat hole and snap in the other side. I have a bunch of pictures on the old site but can't find them at the moment.

This was going to be my "go-to" plan if I couldn't find anything else out. I really don't think that mounting the seat to the floor will work for me. Anybody know why Sparco doesn't sell a seat base for this car? I am assuming it's due to the fact that their seats would probably require trans tunnel modification so it's not worth buying the base. I dunno.

I will get some pictures of my setup. I have kerkey that uses the stock front mounts and then we cut the bottom of the set out and modified the seat to then bolt flat onto the floor. It will make more sense with pictures

Looking forward to pictures!

There is a vender that sells a sweet set up that bolts to the stock points, I will try and find it post it.

Much appreciated. The guy I quoted below this linked to a nice looking one. If it's not that and you are able to find it please post it. Thanks!

http://www.good-win-...tml?id=5z9iSPNG

???

That just might be the ticket for me. It says it's predrilled for Sparco sliders and I have a set left over from my last car. Thanks for sharing.

[RussMcB]

I will be sure to post in here with what I end up doing. I hope there will be a lot of examples in here because throughout my research I didn't find much and everything I did find was one setup per thread. Good luck with your build!

I'm glad you started this post, as I'm sure it will help me. It already has (I think). I was browsing ebay tonight and got sucked into bidding on a Carbon Fiber Sparco Pro2000 seat*, which should work well with the Goodwin parts linked above.

I feel a little guilty saying "my build" because the car will be 95% done when I get it. Pretty much everything (cage, engine) will be done except for the seat, belts, gauges, fire system, stuff like that. I'm letting the seller finish the hard stuff, then I get to do the fun, easy stuff.

* http://www.ebay.com/...=p2047675.l2557

[Jason Brassfield]

Maybe this is what Frank was looking at? Looks like a sweet setup.

http://5xracing.com/...seat-mount.html

I just recently bought a few pieces that weren't available locally from 5xracing and they were great to deal with.

[RussMcB]

I have not read the SCCA GCR before posting this, so I deserve whatever chastising you want to toss on me. :-).

I gather (from searching this forum) that if seat sliders are used, a back brace is required.

Also (if I understand correctly), A FIA seat, if solidly mounted (not on sliders), does not require a back brace, but only during the the window of time the FIA sticker is valid (5 years?). In other words, a FIA seat may not need a back brace initially, but will after a few years.

At this point, I'm leaning towards mounting my CF Sparco on sliders, with an adjustable back brace.

Are there challenges attaching a back brace to a carbon fiber seat?

[FTodaro]

Maybe this is what Frank was looking at? Looks like a sweet setup.

http://5xracing.com/...seat-mount.html

I just recently bought a few pieces that weren't available locally from 5xracing and they were great to deal with.

This was not it either but this is a nice set up if you have the room for it.

[Danny Steyn]

One thing that I encourage you to consider carefully is the bolting method through the floor.

When I first started racing I had a really bad accident at Mid Ohio, going into a concrete wall backwards and hitting the wall squarely with he trunk. The impact was so bad and G forces so severe, that my bodyweight moving backwards caused the floor pan to buckle at the mounting points and my head (encased in a top of the line Arai helmet) hit the roof and cracked the paint on the roof and compressed the closed cell poly foam in my helmet. I struggled with concussion that entire weekend, was completely off my game and my head ached for more than a week.

I have had forward impacts at faster speed, but the seat being tied by the belts to the roll bar never moved at all. Now we reinforce the floor under the seat to ensure it will not buckle under load

[Caveman-kwebb99]

One thing that I encourage you to consider carefully is the bolting method through the floor.

When I first started racing I had a really bad accident at Mid Ohio, going into a concrete wall backwards and hitting the wall squarely with he trunk. The impact was so bad and G forces so severe, that my bodyweight moving backwards caused the floor pan to buckle at the mounting points and my head (encased in a top of the line Arai helmet) hit the roof and cracked the paint on the roof and compressed the closed cell poly foam in my helmet. I struggled with concussion that entire weekend, was completely off my game and my head ached for more than a week.

I have had forward impacts at faster speed, but the seat being tied by the belts to the roll bar never moved at all. Now we reinforce the floor under the seat to ensure it will not buckle under load

Good post Danboy... can you post some pics of how you do the floor for everyone to see? Been in two hard hits once forces into a wall at 115mph at mid ohio, I am not sure I am still back to 100 percent after that one, my hip still hurts me, You also made some very good talking points to me at ATL about your seat when I came and ask if it was alright to sit in your car and check out your new seat. I think you may have done more study on this than most of us. please clue all of us in, who knows with as competitve as we have all become it may save someone a major injury, I know I am more serious about my seating now after my 115mph crash.

[Danny Steyn]

Kyle prompted this so if you don’t like what I have written here you can blame Kyle

I came to motor racing with the same mindset that had served me well in my motocross career…….. if you are not crashing your brains out you will never find your limits.

Now I most certainly don’t recommend this for anyone, I was just born with big gonads and a tiny brain. But early on in my motocross career I was deeply influenced by a well executed Bell Helmets advert in MotoCross Action News that simply stated …..“If you have a $10 head, buy a $10 helmet”.

From that day on I purchased the best safety gear available. It didn’t stop me breaking almost every bone in my body or keep me from more than a dozen major surgeries, or keep me from going into a weeklong coma in 1987, but who knows, I might not be here if I didn’t have the safety gear I bought.

So coming back to Spec Miata, in examining the results of my own off course excursions, and there have been many, as well as those of others in a range of other classes, I have taken additional steps in my own car to protect myself better.

• After the Mid Ohio rear impact we added 1/4”steel plate under the floor panel where the seat mounts. This was a bit extreme so now we weld a 1/8” steel plate. We bolt the 8 seat bolts through the floor and plate and use large washers both sides. This will help stop any fasteners pulling through the floorboard and will help resist any buckling of the floor. Unfortunately it adds weight under the driver where you don’t want it. Since we have done this we have seen none of the micro cracks around the seat mounting spots that are often evident when you look at Spec Miatas that have endured hard impacts.
• I have changed my seats from the common full halo seats to full halo and full shoulder containment I use the Racetech 4119 HRW

The full containment seat is a must in my opinion. We have had so many rib breakages and injuries in the last few years that I am surprised that it isn’t mandated. When you have a side impact of any significant force, your hips are contained by the lower seat bolsters, and your head is contained by the full halo. However, the heaviest part of your body, your torso, is unrestrained in the lateral direction. Yes you are strapped in but in a lateral impact you will move sideways under the belts. If the lateral acceleration is to the left you could be be lucky, in our Spec Miatas the roll cage and door will generally stop your movement. But if your lateral acceleration is to the right, your torso will accelerate until something stops it, that is normally your spine and ribs attached to your pelvis that is contained by the lower seat bolsters, and that is where the fractures are happening. There are several very prominent drivers in this class who have had serious rib and rib cartilage injuries in the past few years, as well as many drivers deeper in the field and in other SCCA classes.

The worst impact is the sudden stop against an immovable object. The transfer of energy in a short time (impulse) is what does the damage. Rollovers look spectacular but for the most part they transfer energy over a longer time

By having full shoulder containment, the torso is effectively prevented from accelerating, as it is contained by the seat.

Full shoulder containment seats do present their own issues

• They are typically more expensive (I suspect that prices will drop as they become a commodity)
• They can take up more room in the car and the roll cage typically needs to be finessed around the seat
• They also make egress out the driver’s side more difficult as they take up room in the exit pathway.

So there Kyle – that’s my take on the seat situation. Just one man’s opinion. I encourage everyone to sit in all the commercially available seats, and try them out. It is better if they are firmly mounted and you can be belted in. Then get someone to violently pull on your arms and push on your torso in every direction so you can get an idea of how it contains you.

[FTodaro]

Never worry about blaming Kyle for things even when its not his fault, i do.

Danny let me follow up on one point that supports your opinions. From my limited bio-mechanical background, our anatomy is designed to handle a frontal impact much more so than a lateral impacts. The rib cage will support your internal organs on a frontal impact and hold your heart in place. On a side impact there is not as much support for the heart and other organs, or said another way, there is more room in your chest for your organs to move sideways compared to forwards and back.

So in a side impact it takes much less force to cause a more serious injury, such as a Torn aortic artery. A fatal injury 100% of the time.

I agree with you that you cannot oversell Safety.

So how hard is it to get in and out of that seat with the shoulder containment?

[Keith Novak]

Danny- Great post. When the floor buckled, what happened at the rear mounting points? My thought would be that in a backwards crash the front would pull up and the rear would push down making the reinforcements at the front the most important. Curious as to if that's what you saw or both pulled up.

[john mueller]

I've not read the entire post, so sorry for the unintentional highjack. If you wish to retain the OEM mounting location there is are these two trick little brackets:
This one works best with seats that are under 17" wide (exterior dim) and short dudes, this one is good for under 16.5 wide