cueball1

iTrader: (13)

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.

Loki047

iTrader: (6)

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.

BenR

iTrader: (2)

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

Loki047

iTrader: (6)

Why have two seats when one works?

BenR

iTrader: (2)

Why half *** when you can have the full ***?

Loki047

iTrader: (6)

Half ***? 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?

The_Pipefather

iTrader: (5)

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.

Loki047

iTrader: (6)

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

BenR

iTrader: (2)

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.

Loki047

iTrader: (6)

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

BenR

iTrader: (2)

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.

Loki047

iTrader: (6)

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.

BenR

iTrader: (2)

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 **** 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.

Loki047

iTrader: (6)

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

BenR

iTrader: (2)

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.

BenR

iTrader: (2)

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.

Loki047

iTrader: (6)

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

BenR

iTrader: (2)

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.

Loki047

iTrader: (6)

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

BenR

iTrader: (2)

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.