Seat Back Brace
#1
Posted 12-27-2010 02:07 PM
Thanks!
Dave
#2
Posted 12-27-2010 02:30 PM
Is there any update to the (old) discussion about the seatback braces being needed for FIA seats? I am in the market to purchase a new seat, and this will certainly sway my decision on what I buy. I did a search, but this site is not showing anything (kidding... I searched SpecMiata.com and didn't come up with anything).
Thanks!
Dave
The FIA seats time-out at 5 years(past manufacture date on seat sticker). A brace needs to be added for compliance with NASA and SCCA after the seat has timed-out. I don't think anything has changed except someone made the proposal to require braces early this year - it was not implemented. The FIA rating would be void if you drilled the seats, so I doubt it will happen but you never know...
#3
Posted 12-27-2010 04:12 PM
9.3.41. SEATS
The driver’s seat shall be a one-piece bucket-type seat and shall be
securely mounted. 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 FIA Standard 8862-2009 or higher need not have
the seat back attached to the roll structure. Seats with a back not attached
to the main roll hoop or its cross bracing may not be mounted to
the stock runners unless they are the FIA homologated seats specified in
an FIA homologated race car. The homologation labels must be visible.
Seat supports shall be of the type listed on FIA technical list No.12 or
No. 40 (lateral, bottom, etc). Passenger seat back–if a folding seat, it
shall be securely bolted or strapped in place.
#4
Posted 12-27-2010 05:03 PM
8855-1999 or FIA Standard 8862-2009? The first one is the old seat standard(1999) the second one is the new seat standard (2009). So what really changed?
"Seats with a back not attached
to the main roll hoop or its cross bracing may not be mounted to
the stock runners unless they are the FIA homologated seats specified in
an FIA homologated race car. The homologation labels must be visible.
Seat supports shall be of the type listed on FIA technical list No.12 or
No. 40 (lateral, bottom, etc)..."
Sounds like list no 12 and 40 are relevant huh? I Looked them up and no 12 is the list of 1999 FIA Seats and no 40 is a short list of FIA seats that appear to have back brace hardware pre-installed. Maybe I'm reading it wrong but the whole thing sounds like all it does is outlaw sliders. I should have gone to law school...
#5
Posted 12-27-2010 05:19 PM
You passed the bar (or at least this one). Sliders are only OK if they came as original equipment in an FIA homologated car. The reason for the change is that many FIA seats when mounted to the stock sliders are simply not anchored well.Sorry, I stand corrected. The question is then: what is FIA standard
8855-1999 or FIA Standard 8862-2009? The first one is the old seat standard(1999) the second one is the new seat standard (2009). So what really changed?
"Seats with a back not attached
to the main roll hoop or its cross bracing may not be mounted to
the stock runners unless they are the FIA homologated seats specified in
an FIA homologated race car. The homologation labels must be visible.
Seat supports shall be of the type listed on FIA technical list No.12 or
No. 40 (lateral, bottom, etc)..."
Sounds like list no 12 and 40 are relevant huh? I Looked them up and no 12 is the list of 1999 FIA Seats and no 40 is a short list of FIA seats that appear to have back brace hardware pre-installed. Maybe I'm reading it wrong but the whole thing sounds like all it does is outlaw sliders. I should have gone to law school...
Dave
#6
Posted 12-29-2010 09:48 AM
You passed the bar (or at least this one). Sliders are only OK if they came as original equipment in an FIA homologated car. The reason for the change is that many FIA seats when mounted to the stock sliders are simply not anchored well.
Dave
And to be absolutely clear, this rule as written outlaws STOCK sliders, but not all sliders. Sparco and Recaro each build/sell their own sliders which should still be legal. In fact, if you want to go by the literal interpretation of the rule, using sliders from any other car should be legal, as long as they aren't the "stock" sliders for the car in question...
I was one of the people that wrote multiple letters to the CRB on this topic. While the wording they ended up with is better than every other proposal I read, it still leaves a lot to be desired. I am certain the lack of clarity in the rule, as written, will result in many disagreements at Tech about what is and what is not legal from a seat-mounting standpoint.
Cheers,
Dean
Former driver
#7
Posted 12-29-2010 09:55 AM
Also, the way I understand the FIA seats to work is that they are designed to flex. The difference between the FIA seat and the aluminum seat is the FIA seat flexes and returns to normal, where the aluminum seat bends and stays bent.
Seems to me that mounting a fixed seat back would do a couple of real bad things.
- Introduce weak points where drilled
- when the seat flexes (or tries to flex) it will break where the new weak point was introduced
- would increasingly lower the life of the glass seat (one bump and the seat would most likely be toast)
#8
Posted 12-29-2010 11:17 AM
Interesting...
Also, the way I understand the FIA seats to work is that they are designed to flex. The difference between the FIA seat and the aluminum seat is the FIA seat flexes and returns to normal, where the aluminum seat bends and stays bent.
Seems to me that mounting a fixed seat back would do a couple of real bad things.I heard that you can have an expired FIA seat looked at for rectification. What is the process for that and what do they do to the seat to see if it is still structurally intact?
- Introduce weak points where drilled
- when the seat flexes (or tries to flex) it will break where the new weak point was introduced
- would increasingly lower the life of the glass seat (one bump and the seat would most likely be toast)
I can't answer your recertification process question but...FIA seat prices are pretty reasonable right now(especially head and upper body containment seats),couple that with round trip shipping, recertification fees and you still have an old seat. I just got a great seat for 700 bucks. It's a no brainer to me...
#9
Posted 12-29-2010 02:34 PM
Interesting...
Also, the way I understand the FIA seats to work is that they are designed to flex. The difference between the FIA seat and the aluminum seat is the FIA seat flexes and returns to normal, where the aluminum seat bends and stays bent.
Seems to me that mounting a fixed seat back would do a couple of real bad things.I heard that you can have an expired FIA seat looked at for rectification. What is the process for that and what do they do to the seat to see if it is still structurally intact?
- Introduce weak points where drilled
- when the seat flexes (or tries to flex) it will break where the new weak point was introduced
- would increasingly lower the life of the glass seat (one bump and the seat would most likely be toast)
Holes do make weak points. Adding too much stiffness in the wrong places makes failure points too. Plus, since a FIA seat is designed to flex, think of it like falling onto a trampoline. Adding a back brace that wasn't designed with the seat, is like falling on a trampoline with an extra bar through the center.
#10
Posted 12-29-2010 02:50 PM
Holes do make weak points. Adding too much stiffness in the wrong places makes failure points too. Plus, since a FIA seat is designed to flex, think of it like falling onto a trampoline. Adding a back brace that wasn't designed with the seat, is like falling on a trampoline with an extra bar through the center.
Fully agree with this... In addition to once you jump on said imaginary modified trampoline, it breaks and you fall through too. Yikers!
#11
Posted 12-29-2010 04:10 PM
Former driver
#12
Posted 01-02-2011 03:58 PM
There are numerous adhesives on the market to afix an alum. fixture to accomodate the mounting process.
In short don't be in a big hurry to grab the drill!
#13
Posted 01-05-2011 10:05 AM
Mounting the back brace does not require holes!
There are numerous adhesives on the market to afix an alum. fixture to accomodate the mounting process.
In short don't be in a big hurry to grab the drill!
I would be cautious with that method. There are adhesives that will do the job, true enough. If however you aren't really an adhesives expert, I'd grab the drill.
There are lots of things to be considered that most people wouldn't start to consider such as flexibility, strength in various ways such as peel vs. sheer, temp and humidity considerations, surface prep, compatibility with different materials.
Stuff like that is why 9 out of 10 engineers and liability defense lawyers will often recommend sticking with mechanical fasteners for safety critical applications.
#14
Posted 02-07-2011 11:03 AM
#15
Posted 02-07-2011 11:05 AM
Mounting the back brace does not require holes!
There are numerous adhesives on the market to afix an alum. fixture to accomodate the mounting process.
In short don't be in a big hurry to grab the drill!
How would/should you attach a brace to an ultrashield seat? FWIW, this is a NASA application.
Team ///Miata #12
PajamaPants Racing
NASA Midwest
#16
Posted 02-07-2011 07:22 PM
FIA Seats do not "time-Out" for SCCA.
Correct to the letter. SCCA says if it has the FIA sticker it's ok. But, homologation expires at 5 years - that's why the date is there. I would expect them to change since NASA and some smaller clubs already have.
#17
Posted 02-07-2011 09:08 PM
How would/should you attach a brace to an ultrashield seat?
I just bought a new Ultrashield. Old one was attached to the cross brace with a hose strap!
What's the best way! Pics would really help.
#18
Posted 02-07-2011 09:15 PM
#19
Posted 02-08-2011 08:28 AM
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