Race Seats - DIY
 

Has anyone made their own race seats or no someone who has?

I haven't found a seat that will do what i want so i am looking into making my own, just wanted to see if anyone had experience doing this.

Personally... I wouldn't.

It's like making your own racing harness... or helmet... or airbags.

Tried the seat foam mod?

What do they not do that you want them to do?

Are you going to seek a SFI or FIA rating? If not you won't be making a race seat.


I've poured seats for formula cars, but that's a completely different thing.

+1 for what do you want that existing seats don't do?

Kyle (freedomgli) over at CR.net was working on making some carbon fiber or kevlar or something seats, but I dont think he ever finished.

ultrashield seats are real comfy. I went to a dealer and sat in a few cars that they were installed in and I really liked it. They are cheap to buy and the covers seemed high quality

if I could do it all over again, I'd probably have the TDR seats.

The only thing I can say is... DO NOT buy a seat unless you've sat in that model before.

I've had and sat in enough seats over the years to have found that they vary so greatly... that buying it sight unseen is EWW.

ie: Buddy club seats I've found are the golden standard for ME. They fit me like a glove and are comfy for long periods.
I picked up an Ultrashield Spec Miata seat and it Sucked for me. Shoulder harness points were below shoulder (i'm not even a tall person), side bolsters interferred with arms while driving.

Sit in the seats first... I can't emphasize it enough.

Slot of people make thief own seat, and if I can meet a sanctioning body guidlines I don't see why it would be an issue. Alot of people Make their own seats and belts.

There are some features that I want and I can go into more detail later.

Seats are safety items. No way in hell would I ever sit in a homemade race seat on track. My belts and seats are FIA cert through 2011.

Safety item really? Never thought of that.... I trust my design and fab skills alot more than some seat Made in china. As long as the nylon is stiched correctly there should not be an issue.

my shit is not made in chine. Remember that thread I made a long time ago about the guy dieing in his s2k in an HPDE?

He needs a seat to accommodate the stick in his ass.

Well that's one part of it....

Please do.

side bolsters. I find most production race seats to be a give and take between true race seat and something you can drive on the street. I find this to mostly accomplished by changing the side bolsters. Basically I have a surprisingly easy and efficient way of having removable side bolsters. A bolt set up that will keep the bolts in tensions the entire time, and removing shear from the equation.

I'd be weary of removable bolsters in a crash.


Have you had a chance to sit in a ultrashield rally seat with full harnesses on? For me it's the best cost effective compromise I've found.

The bolts would be stronger than the material the seat is made out of. The seat is bolted to the floor, I am not to worried about it.

Loki,

I'm not against your DIY seats at all. I'm just curious about what you want in a seat you haven't found in the existing market yet?!?

Removeable bolsters? Adjustable bolsters? Other features?

I wonder if it might be easier to modify an Aluminum framed seat like Kirkey or Ultrashield do do what you want. The frames are strong and reletively inexpensive. Might also be easier to work with their seat covers to than sewing your own from scratch.

I want a seat that can have removeable bolsters, so I can readily get in and out of the car for tuning/testing, but when actually driving i want to have bolsters.

Why not get a good race seat for track use, and a stock seat for tuning? It's only 4 bolts to swap them.

Why have two seats when one works?

Why half ass when you can have the full ass?

Half ass? I would go with a custom made seat with some sort of force analysis is better than some seat that I know nothing about. Do you know how they analyzed the seat you are buying?

Designing a seat from scratch (the proper way) is not a trivial task. The structural analysis can be done by hand but an infinitely easier way is to use a linear FEA package. That will take a fair bit of time, and may NOT predict fatigue effects (which can have a significant effect if the seat is built of aluminum), unless you are using very high-end software like hypermesh/optistruct. In cases like these, the only thing to do is overbuild.

My advice: Buy an aluminum seat like Kirkey where all the structural and fab work is done for you already, then spend your time on bolstering it to your requirements. I am pretty sure there is nothing that you can do better over what Kirkey or Ultrashield have already done for you.

Other people's engineering is often the cheapest to buy in terms of both time and money.

I was definitely staying away from Aluminum only because of fatigue issues. Other peoples engineering is cheaper, but not better. And once i spend time bolstering it I will have to verify the frame still meets my standards. I would rather just start from square one.

I will probably end up running the seat through mechanica for FEA

I'm not trying to be a dick here, just pointing out that what you want to accomplish can be done alot easier and cheaper.

If you do intend to race this car I could see a tech inspector shitting all over having moveable or removable bolsters.

There's a reason real race seats don't recline, or typically have moveable parts.

No to be honest any constructive criticism i appreciate. As long as the seats meet the guidline without the bolts the addition bolsters shouldnt be an issue. Plus I can relatively easily and clearly prove that the bolsters would be stronger than the seat mounting itself.

My thought process.

1) Prove seat with out bolsters pass tech
2) Prove that the bolsters do not decrease stregnth or safety of seats

FYI here is the seat section from the SCCA GCR.

I think the part about it being one-piece may hurt your idea.



9.3.40. SEATS

The driver’s seat shall be a one-piece bucket-type seat and shall be securely mounted. In cars where the seat is upright the back of the seat shall be firmly attached to the main roll hoop, or its cross bracing, so as to provide aft and lateral support. Seats homologated to and mounted in accordance with FIA standard 8855-1999 or higher need not have the seat back attached to the roll structure. The homologation labels must be visible. Seat supports shall be of the type listed on FIA technical list No.12 (lateral, bottom, etc). Passenger seat back - if a folding seat, it shall be securely bolted or strapped in place.A system of head rest to prevent whiplash and rebound, and also to prevent the driver’s head from striking the underside of the main hoop shall be installed on all vehicles. Racing seats with integral headrests satisfy this requirement.The head rest on non-integral seats shall have a minimum area of thirty-six (36) square inches and be padded with a minimum of one inch thick padding. It is strongly recommended that padding meet SFI spec 45.2 or FIA Sports Car Head Rest Material. The head rest shall be capable of withstanding a force of two-hundred (200) lbs. in a rearward direction. The head rest support shall be such that it continues rearward or upward from the top edge in a way that the driver’s helmet can not hook over the pad.

I have to look up the FIA rules...

"if a folding seat, it shall be securely bolted or strapped in place."

Folding seat makes me think the one piece bucket is misleacding and might be refering to the actual seat bucked that mounted to the car. I have to look into it, but if my seat passes inspection without the bolsters then I should be alright.

You may want to give the guy who will be doing your annuals a call. I know what my local SCCA tech inspector would say, but yours may be different.


To me it's pretty clear it's not talking about the drivers seat but the passenger seat.


The full sentence reads:

"Passenger seat back - if a folding seat, it shall be securely bolted or strapped in place."


Meaning, if you don't remove the stock seat on the passenger side, you'll need to brace the back either with a strap or bolting it something solid like the rollcage, so that shit doesn't become a projectile in a crash.


For FIA certs you'll need to probably ship them a seat or two. For testing and evaluation.

Do you have the link to the full spec? Guess I didn't read it too clearly. Also, maybe I need to sit down and read this in full but I am not seeing that the seat has to be FIA cert.

PS: I dont plan on doing SCCA.

PPS: I dont know what annuals are

I think FIA certs are only good for 5 years from date of manufacture.


Here's the SCCA stuff.


www.scca.com/documents/Club%20Rules/GCR2008.pdf


9.3.40. SEATS


The driver’s seat shall be a one-piece bucket-type seat and shall be securely mounted. In cars where the seat is upright the back of the seat shall be firmly attached to the main roll hoop, or its cross bracing, so as to provide aft and lateral support. Seats homologated to and mounted in accordance with FIA standard 8855-1999 or higher need not have the seat back attached to the roll structure. The homologation labels must be visible. Seat supports shall be of the type listed on FIA technical list No.12 (lateral, bottom, etc). Passenger seat back - if a folding seat, it shall be securely bolted or strapped in place.A system of head rest to prevent whiplash and rebound, and also to prevent the driver’s head from striking the underside of the main hoop shall be installed on all vehicles. Racing seats with integral headrests satisfy this requirement.The head rest on non-integral seats shall have a minimum area of thirty-six (36) square inches and be padded with a minimum of one inch thick padding. It is strongly recommended that padding meet SFI spec 45.2 or FIA Sports Car Head Rest Material. The head rest shall be capable of withstanding a force of two-hundred (200) lbs. in a rearward direction. The head rest support shall be such that it continues rearward or upward from the top edge in a way that the driver’s helmet can not hook over the pad.

Where do you plan on racing?


Annuals are your annual tech inspection every car that races has to undertake. Every racing club I know of does annuals, from my local vintage group to the SCCA, to NASCAR.



P.S. FIA certs aren't required, unless you do not want to mount the seat with a back brace, as long as the seat is mounted in accordance with the FIA required mounting procedure.

I was thinking NASA. I haven't had a lot of fun with the local SCCA club.

If you intend to race with NASA the safety stuff is pretty much identical. Especially since their classing and rules at the start were directly copied from the SCCA.

Their specs are pretty relaxed at least from the little I've skimmed. Take a look and see if you disagree.

You should contact your local NASA tech inspector that will actually be doing your annual. He as the final say, despite what the random "BenR guy on the internets" says.


If it was my neck as a tech inspector, I wouldn't sign off the log book to pass it. But I take my safety and liability seriously.

I know thats why I want to build my seat right.

Nylon? You must be joking. There isn't an FIA seat on the market that isn't a fiberglass or carbon/kevlar bucket, and some people won't use anything except carbon/kevlar. My seats are made in Italy by MOMO.

If I were an instructor, I wouldn't ride in your car. If I were a tech inspector, I wouldn't sign your car off. Take that as you will.

Referring to seat belts, get with it.

I guess I should preface this by saying that I'm not trying to be a dick, & that I'm a huge DIYer, but seats are one thing I wouldn't touch.

I can see the appeal of wanting to make a seat like your but IMO there are reclining seats that are a good compromise for what you're looking for. If you plan on racing the car than an FIA bucket is the only way to go and probably the only way you'll pass tech.

Harness Helmet Seat and Bar are some of the most important features in a car and IMO I wouldn't chance it. Lots of time, money, and research goes into making any reputable seat.

Not to mention how many people have died in the past year from safety features and improper harness mounting. To be honest the people on this forum are nice because if you posted this in the bimmerforums track section they'd be sh!tting themselves at the idea of someone going to the track in a homemade seat.

I don't mean any harm in this, but the impact and forces that a seat can see in an accident make it too risky for me to take a chance (even if you are great at fabrication and over engineer the seat).

I rally do appreciate everyones Input but I get it you guys don't think it's possible. I wasn't asking for your design inputs or opinions on safety. I was looking for references or information.

And after looking through the fia test requirements the forces they are subjecting the seat are less than I would have designed for. What is difficult is the lack of a test stand to replicate their requirements. The test reaffirmed my I itial thoughts that why the seat is a saftey item the belts are truley what matter.

Don't be such a fucking jew and buy a seat. Oh wait ... :)

HA! But In the end i bet this will be more expensive.