not safe is a back brace on a composite seat, with a mount fab'ed by the owner. some FIA seats have back brace mounts built in. These are safe, and in the case of Racetech, required to be in conformance to 8862-2009. Racetech is the only 1 out of 4 seat manufacturers on that list to homologate their seats with back braces. only about 10 8855-1999 seats were homologated with a back brace, all but 3 of those are Racetech (the others are GM and BMW, I might have missed one more). The rest are only lateral or lower mounting to an unspecified bracket.Originally Posted by jumbojimbo
not safe is a shotty mounting of the seat to the thin floorboard of a 50 year old production car using bolts and standard washers. or 10 years old. still too thin.
not safe is a lot of production car seat sliders being used to mount a racing seat. often this is more true if the sliders are modified.
the rules state no FACTORY sliders wihtouyt a back brace. this is a good start, I guess - the back brace requirement still needs to be eliminated for seats that aren't designed for it, and such seats need to be mounted appropriately or disallowed, period.
FIA does NOT homologate seat mounts EXCEPT those homologated WITH the seat to 8862-2009 (tech list 40). on the Recarro brochure page cited above, the specific models homologated with those seat mounts are called out under the bold "Recaro racing shells" (for what it's worth, the seat mount cited in the homologation is Recaro PN 7307802). so we are left with having to DECIDE, in a repeatable manner, if an aftermarket, adjustable seat mount is sufficiently strong for mounting a racing seat because the GCR does not address this (except by omission), nor does the FIA ( which I feel the GCR is pointing to for acceptance criteria based on wording that was in the proposed rules, and since stricken / not adopted).
Most if not all of the adjustable seat mounts offered by the seat OEMs for use in motorsports are more than sufficient, but other aftermarket sliders often times are not. ditto many (not all) car OE sliding mounts. without some sort of identification and testing, it's too friggin hard to say what's good enough, objectively. SCCA chose to not trust what came in the car, and anything else is fair game. I think the restriction should be tighter than that, and manufacturer should be evident at minimum, and be a manufacturer of note with FIA homologated product, OR a list of allowed sliding mounts needs to be generated to get around the issue.
STATIC mounting remains, to me, and issue because the specification in the GCR are too slim and inadequate for making a reasonable baseline standard for mounting strenght. all one needs to do is adapt some of the rules from seat belt mounting for this purpose (load spreading washers, minimum hardware grades, etc...) to make a big improvement to the rules as they stand.
I wrote a LOT of letters and did a lot of leg work (phone work) talking to a lot of seat manufacturers, resellers, and reps, taking measurements, and getting information to shoot down the back brace requirements as they were floated. what we have now is an imperfect rule thats a lot better than the potential alternative would have been (requireing back braces on any seat without FIA approved mounts, which don't REALLY exist).
my appologies, steve, if I came accross in support of a back brace bolted to holes drilled in a composite seat. I wouldn't waste time crash testing such a setup for fear of writing off an expensive dummy. it's a ludicrously bad idea, and rather than encouraged, it should disallowed outright.
the trouble here is that many club racers aren't building to GrandAm quality, or on a GrandAm budget. they might have a welder... and a few dollars, and oh shit, this rule just changed... oh, look - these mounts from APC fit my honda, easy button! ouch - I'm dead. there's a BIG technology and prep level variation in the padock. anyone who works tech (like steve, tGA, myself, many others) knows this very well. the rules have to address this to keep the unsafe out, and minimize arguments and subjective mistakes at the tech shed.
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