Seat Back Brace Question

[lateapex911]

So, let me boil this down if I can.
I CAN: Mount an FIA seat to FIA side or bottom mounts (if the seat was tested with the ones I've selected) and bolt those to my sheet metal floor.

But I can NOT weld a cross car tube or box section or two from my roll cage to the tunnel (In IT) and attach with proper grade hardware recaro sliders that have been in use in Grand Am cup and ALMS for years?

IF that's correct, who's doing the logic tests for the ruleswriters?

yea yea yea, I know, "It's based on the advice of legal counsel".

[Chip42]

Jake,

you CAN mount an FIA seat in ANY fashion you like OTHER than to stock sliders. so the recaro etc... double locking bits ARE OK per 9.3.41.

you CAN have extensions from your cage to the tunnel to use for a seat mount - see 9.3.41, paragraph 2. even in IT/SS etc...

the only restriction for FIA seats (other than a back brace must be used with stock sliders) is that the bolts to the seat go into the homologated holes (lateral or lower) as some seats have both but only were homologated with one.

the problems some of us have with the rules are

1 - there are no minimum standards for propper mounting (thus the brackets pop-riveted to the floor example which is completely legal)

2 - aftermarket runners MIGHT be just as unsafe as stock, as there is no homologation standard for or list of approved sliding mounts. so some aftermarket, non race worthy part could be passed as it is not stock. This does not include most/all of those made by the major FIA homologated seat suppliers (OMP, sparco, racetech, etc...) but there's still no objective standard other than "not stock".

[Russ Myers]

how can stock be considered unsafe when they are crash tested to nhtsa and dot standards. I crashed a fiesta with a stock seat at road atlanta and had no problems what so ever.

Russ

[joeg]

Russ--Yes you are probably correct. I have no clue why a modern OEM seat would not work well in a race car (other than for its weight).

[seckerich]

And the fact that the factory seat mounts were attached to a seat structure that was engineered to give it extra strength. Most are single locking, and not full captive. Now you are attaching it to a carbon, fiberglass, etc. seat without that steel frame and it will not perform the same way. Not safe.

[lateapex911]

Jake,

you CAN mount an FIA seat in ANY fashion you like OTHER than to stock sliders. so the recaro etc... double locking bits ARE OK per 9.3.41.

OK, reading the GCR rule, it says "supports must be of the type listed on FIA tech list.....".
So, am I correct in deducing that I can use ANY support in ANY way, as long as I use the right type...side or lower as listed? And i can mount those to any slider other than the stock sliders or heck I can glue them to the floor with bubble gum, again, as long as I don't involve stock sliders, unless THEY are FIA listed as such??

you CAN have extensions from your cage to the tunnel to use for a seat mount - see 9.3.41, paragraph 2. even in IT/SS etc...

Thanks, I missed the new section on my first run though the new GCR.

the only restriction for FIA seats (other than a back brace must be used with stock sliders) is that the bolts to the seat go into the homologated holes (lateral or lower) as some seats have both but only were homologated with one.

the problems some of us have with the rules are

1 - there are no minimum standards for propper mounting (thus the brackets pop-riveted to the floor example which is completely legal)

2 - aftermarket runners MIGHT be just as unsafe as stock, as there is no homologation standard for or list of approved sliding mounts. so some aftermarket, non race worthy part could be passed as it is not stock. This does not include most/all of those made by the major FIA homologated seat suppliers (OMP, sparco, racetech, etc...) but there's still no objective standard other than "not stock".

OK, I'm with you...
Another Head and Neck rule.
Again, to those reading who write the rules, you have to see how when we read these rules, and obvious limits are placed on one aspect of a system, yet the rest of the system is 'free', it makes placing ANY limits on any part of the system look, well, stupid. In this case it's "Must have a backbrace, can't use stock sliders, etc". but no mention of actual attachment, so, ergo it all CAN bolt to the floor using spit....it just makes little sense.

And sure, you can say, "Well, you're racers, you know how to properly mount a seat...". Yup, I do, but I also know how to use the best head and neck restraint, and I can get out of it in a nano second even though it requires more than one release, yet you won't let me use that one, I have to use an inferior one....so lets not play the "you're smart enough to figure stuff out" card.

[seckerich]

There is also no "FIA" or any other spec for the required back brace. Even if required it can be of creative design so as not to endanger the drivers spine.

[Chip42]

it CAN be, but the easy button is one of the IO port type spears. lots of people who race would never assume something sold as safety equipment could actually make them less safe.

like using pipe insulation / pool noodles instead of energy absorbing, fire retardant roll bar padding. it can actually make a bad situation worse.

rules makers need to either LET people be unsafe, or enforce stuff that actually leads to safety.

[Simon T.]

I created a monster. lol

Good info in here!

[Bremsen]

Ok, see fire....have gas....will throw.

Both the SCCA and NASA rule books on using the FIA seat say they must be mounted in accordance with the FIA standard. My question is regarding the harness mount as the FIA standard/test procedure states the seat back must be a minimum of 150mm from the cage and harness must be mounted between 200-250mm from the seat back (2" window?). Am I to understand that if that dimension cannot be met due to cage design/seat positioning that a back brace of some sort must be used with the FIA seat? Or is that only for the homologation test procedure?

-Ryan

[Chip42]

Am I to understand that if that dimension cannot be met due to cage design/seat positioning that a back brace of some sort must be used with the FIA seat? Or is that only for the homologation test procedure?

Ryan, you're reading the instalation procedure for the homologation sled test, not into the car. My guess is that they aim to minimize but not remove the effects of the belts on the performance of the seat by using "average instalation" numbers.

The FIA standard for mounting an 8855-1999 seat is simply to mount it using those mounitng locations that were homologated (lower, lateral), and that those mounts be secure to the car. Some seats have both and only were homologated with one (typically lateral) others were tested with both, know your seat and make sure you're doing it right by referencing technical list 12 (link). contrary to popular belief, there is no FIA standard for seat mounts outside of those associated with the seat via 8862-2009, but all of the major seat manufacturers standard brackets are up to the task (many are made by the same factory). any catelog that lists brackets as "FIA approved" is not sufficeint evidence for homologation, but does mean that at some point an instalation using those mounts passed fia muster (or it's falacious information).

Your cage and the seats position have no bearing on each other outside of good design, but that's not in the GCR. Do check that you have clearance around the seat, that it is not "preloaded" by contact with or immediately next to a bar in the cage including the back (contact with the lower portion is more acceptable). make sure you have head room, pad any hard point you could get your head to. ensure that the belts are routed through the seat holes, not by them (the belt should not be deflected by the seat when tight). and use good hardware to mount the seat, mount to strong points, cage etensions, or using large, strong washers or drilled plate to spread the loads on the floor.

[Chip42]

some good guidance on seat mounting (not necessarily SCCA compatible but I saw nothing that jumped out at me, in general it is more strict) can be found here, article 16, pages 18-19. This is from European tourring car rules.

[Streetwise guy]

From the original FIA rules: http://argent.fia.com/web/fia-public...11)-161209.pdf
Page 17 has the diagrams. Beware the braion cramps caused by attempting to read the FIA rule book.

ARTICLE 16 : SEATS, ANCHORAGE POINTS AND SUPPORTS

If the original seat attachments or supports are changed, the new
parts must either be approved for that application by the seat
manufacturer or must comply with the specifications mentioned
below :

1) Anchorage points for fixing the seat supports:

The seat supports must be fixed either:
- on the anchorage points for fixing seats used on the original car
- on the anchorage points for fixing seats homologated by the
manufacturer as an Option Variant (in which case the original
anchorage points may be removed)
- on anchorage points for fixing seats in conformity with Drawing
253-65B.
The seat supports must be fixed to the anchorage points for fixing
seats via at least 4 mounting points per seat, using bolts
measuring at least 8mm in diameter.
253-65B

INSTRUCTIONS DE MONTAGE

1- Percer des trous (Diamètre supérieur au périmètre des écrous)
dans le bas de caisse et la paroi du tunnel central.
2- Souder les écrous sur les contre plaques puis souder celles-ci
sur le bas de caisse et la paroi du tunnel central.
3- Souder les 2 inserts filetés dans la traverse puis souder les 2
platines aux extrémités de celle-ci.

FITTING INSTRUCTIONS

1- Drill holes (larger than nut outer diameter) in the bodyshell lower
rail and in central tunnel wall.
2- Weld the nuts on the counterplates, then weld these on the
bodyshell lower rail on the central tunnel wall.
3- Weld the 2 threaded inserts in the crossmember, then weld the
endplates at each end of the crossmember.

FIA Annexe J / Appendix J – Art.253

FIA Sport / Département Technique 18/19 CMSA / WMSC 11.12.2009
FIA Sport / Technical Department Publié le / Published on 16.12.2009

4- Fixer l’ensemble par les 4 vis M8 classe 8.8 qui se visseront sur
les écrous soudés.

2) Fixation des supports de sièges directement sur la
coque/châssis

Les fixations sur la coque/châssis doivent comporter au minimum
4 attaches par siège utilisant des boulons de 8 mm minimum de
diamètre avec contreplaques conformément au Dessin 253-65.
Les surfaces de contact minimales entre support, coque/châssis et
contreplaque sont de 40 cm

2 pour chaque point de fixation.
4- Fix the assembly through 4 M8screws of 8.8 grade which will be
screwed in the welded nuts.

2) Fixing of the seat supports directly onto the
shell/chassis

Supports must be attached to the shell/chassis via at least
4 mounting points per seat using bolts with a minimum diameter of
8 mm and counterplates, according to the Drawing 253-65.
The minimum area of contact between support, shell/chassis and
counterplate is 40 cm

2 for each mounting point.
253-65

3)

Si des systèmes d'ouverture rapide sont utilisés, ils
doivent pouvoir résister à des forces horizontale et verticale de
18000 N, non appliquées simultanément.
Si des rails pour le réglage du siège sont utilisés, ils doivent être
ceux fournis à l'origine avec la voiture homologuée ou avec le
siège.

4)

La fixation entre le siège et les supports doit être
composée de 4 attaches, 2 à l'avant, 2 sur la partie arrière du
siège, utilisant des boulons d'un diamètre minimum de 8 mm et
des renforts intégrés aux sièges.
Chaque attache doit pouvoir résister à une charge de 15000 N
quelle qu'en soit la direction.

5)

L'épaisseur minimum des supports et des contreplaques
est de 3 mm pour l'acier et de 5 mm pour les matériaux en alliage
léger.
La dimension longitudinale minimale de chaque support est de
6 cm.

6)

En cas d’utilisation d’un coussin entre le siège
homologué et l’occupant, ce coussin doit être d’une épaisseur
maximale de 50mm.
Tous les sièges des occupants doivent être homologués par la FIA
(normes 8855/1999 ou 8862/2009), et non modifiés.
La limite d'utilisation est de 5 ans à partir de la date de fabrication
mentionnée sur l'étiquette obligatoire.
Une extension supplémentaire de 2 ans peut être accordée par le
fabricant et doit être mentionnée par une étiquette supplémentaire.

ARTICLE 17 : SOUPAPES DE SURPRESSION

Les soupapes de surpression sont interdites sur les roues.

3)

If quick release systems are used, they must capable of
withstanding vertical and horizontal forces of 18000 N, applied
non-simultaneously.
If rails for adjusting the seat are used, they must be those originally
supplied with the homologated car or with the seat.

4)

The seat must be attached to the supports via
4 mounting points, 2 at the front and 2 at the rear of the seat, using
bolts with a minimum diameter of 8 mm and reinforcements
integrated into the seat.
Each mounting point must be capable of withstanding a force of
15000 N applied in any direction.
5) The minimum thickness of the supports and
counterplates is 3 mm for steel and 5 mm for light alloy materials.
The minimum longitudinal dimension of each support is 6 cm.

6)

If there is a cushion between the homologated seat and
the occupant, the maximum thickness of this cushion is 50 mm.
All the occupants' seats must be homologated by the FIA
(8855/1999 or 8862/2009 standards), and not modified.
The limit for use is 5 years from the date of manufacture indicated
on the mandatory label.
An extension of 2 further years may be authorised by the

manufacturer and must be indicated by an additional label.

[Bremsen]

Thanks for the clarification Chip42/Streetwise.

[JoshS]

I admit, I haven't been following this seat brace mess.

Can someone boil it down for me? I have an FIA-approved Sparco Circuit that is less than 5 years old.

It is a side-mount seat, and I am using Sparco side mount brackets. The brackets are bolted to an adapter, which in turn is bolted into my car using the same mounting points that the stock seat uses. There is no slider.

Do I need a seat back brace now?

[seckerich]

If it slides, yes. If it is fixed no. CRB screwed that for us all.

[JoshS]

If it slides, yes. If it is fixed no. CRB screwed that for us all.

Thanks Steve. No sliders for me, the seat is fixed. I used to have Sparco sliders too but they had too much play, I couldn't stand them. For enduros we just find a seat position we can all live with.

[seckerich]

My old ITS car had a custom setup where the lower door bar on the left and a parallel bar along the tunnel had a sleeve inside and slots milled for 6 inches of travel. Four quick pins held it in position and it could easily be moved during enduro stops. Might go that route with the new car especially now that the inner tube can be welded to the floor/tunnel.

[Knestis]

Got my annual at Summit this past weekend and they did check for runners on my FIA seat, and one tech guy explained the new rule to another new guy. They didn't find any.

K

[Greg Amy]

I've already made two logbook entries of "fix before next race" to folks that didn't know. One had to bail on his first race because he couldn't fix it in time...