MikeColangelo Michael Colangelo Ultra Moderator Location: California Join Date: 10/21/2009 Posts: 209 Rally Car: Spec Miata |
On a Mazda racing forum, there have been several discussions on the legality and safety of using seat sliders in a road racing race car. I know many rally racers use the heavy-duty Sparco seat sliders in their rally cars, especially ones that are shared among different drivers. So my question is this, has anyone seen or heard of a Sparco seat slider (or other heavy-duty equivalent) failing in a crash? Let's define failing as structurally breaking or allowing the seat to slide when it should have stayed locked in place.
Do the pro teams use seat sliders? I'm just curious. It seems like the SCCA is putting out some very conservative road racing safety rules lately and I sometimes wonder how realistic these rules are. |
MikeColangelo Michael Colangelo Ultra Moderator Location: California Join Date: 10/21/2009 Posts: 209 Rally Car: Spec Miata |
Here's the recently clarified SCCA rule regarding the use of seat sliders in a road race car:
4176 (CR ![]() Clarify 9.3.41 as follows: “Seats with a back not attached to the main roll hoop or its cross bracing may be mounted on runners only if they were part of the FIA homologated seat assembly specified in an FIA homologated race car.†Basically, it's stating that unless your FIA race seat was tested with the seat sliders and mounts as part of a "FIA homologated seat assembly", you must use a back brace if you want to use seat sliders. Anyone care to drill holes in teh back of that $1000 kevlar seat? ![]() |
phlat65 Sean Medcroft Elite Moderator Location: Edmonds, Washington Join Date: 02/12/2009 Age: Possibly Wise Posts: 1,802 Rally Car: Building a Merkur |
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heymagic Banned Super Moderator Location: La la land Join Date: 01/25/2006 Age: Fossilized Posts: 3,740 Rally Car: Not a Volvo |
Many teams have a disparity between driver and co-driver in height. It may be required that a co-driver or someone else drive the car and a fixed seat might prevent that. Also a seat that moves back can make entry and egress a heluva lot easier.
So lets talk about movement. Where the heck is the seat going to go in a wreck? In a side impact there isnt any real load on the sliders, just the bolts. Hit a tree head on, the load is absorbed by the belts, not the sliders. So a rear impact is about the only danger to the sliders and then you would move back to the main cage, but you're still in the seat. So if you get hit in the back and the sliders break and then you go forward...wait the belts still stop you. So I don't see the big issue, but the seat has to have dual latches on the sliders and not just one side. Anything other than a direct forward or rearward impact also loads the slider in a binding motion further reducing the load on the locks, so less danger there. |
DaveK Dave Kern Ultra Moderator Location: Centennial Join Date: 07/11/2008 Age: Midlife Crisis Posts: 1,085 Rally Car: Compact M3 & Evo IX |
I had sparco sliders on a base mount Momo seat when my GTX was a daily driver. I'm pretty sure when the cage went in we devised a more solid mounting system. I'd never use them again in a race car as they seemed to allow just a little bit of movement...especially when compared to the side mount Racetechs. Seems to me it's adding one more potential failure point.
Dave |
Rallymech Robert Gobright Elite Moderator Location: White Center Seattle Join Date: 04/27/2008 Age: Possibly Wise Posts: 1,292 Rally Car: 91 VW GTI 8V |
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wvonkessler Wilson von Kessler Elite Moderator Location: Lookout Mountain, GA Join Date: 02/28/2006 Age: Possibly Wise Posts: 1,127 Rally Car: Colts are in Finland; now '87 325i, '89 325i |
We have our seat mount set up so that the side mounts can be moved forward or backward, enough so that the car can fit from a 5'2" female driver to a 6'2" male driver without the use of sliders. Feel much safer than with sliders. Plus, that language regarding FIA sliders is smoke, because there is no such thing, at least in my investigation, of a homologated slider.
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heymagic Banned Super Moderator Location: La la land Join Date: 01/25/2006 Age: Fossilized Posts: 3,740 Rally Car: Not a Volvo |
I don't think I've ever seen FIA address slider either. I have sen language somewhere about the homolgated seat needing a homolgated slider.
It's a personal choice. In 40 years of auto repair I've not seen any big issue with sliders coming loose, usually the frickin things stick. I have had a couple stockers not grip tho, but that has always been either massive dirt, rust or shit under the car seat. I can't remember an actual failure...not to say there hasn't been. Most race cars have fixed seats and a driver change requires the seat insert or shell changed. hard to do on stage. Lets say a vertically challenged driver (5'4" ![]() Sliders can also be pinned to further strengthen if it is a real problem. Personally I like them for ingress and egress as well as being able to change position to help the old abused back and legs....but it definitely is a personal choice and I don't any answer is right or wrong. |
fliz Chad Eixenberger Elite Moderator Location: Grafton, WI Join Date: 02/01/2007 Age: Midlife Crisis Posts: 484 Rally Car: 1988 VW Golf #687 |
I remember my first crewing experience, for Matt Johnson. I was asked to pull his car into the teardown area for post-race inspection. I got halfway in and realized I wasn't going to be able to get my knees past the steering wheel. Embarrassed, I had to crawl back out and get somebody else to move the car. Bushore has sliders, and has crashed his car plenty w/o a failure (although I don't know that you'd consider any of the crashes "bad" ![]() Edited 1 time(s). Last edit at 11/12/2011 02:02PM by fliz. |
MikeColangelo Michael Colangelo Ultra Moderator Location: California Join Date: 10/21/2009 Posts: 209 Rally Car: Spec Miata |
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NoCoast Grant Hughes Godlike Moderator Location: Whitefish, MT Join Date: 01/11/2006 Age: Midlife Crisis Posts: 6,818 Rally Car: BMW |
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SteveL Steve Leitch Junior Moderator Location: Ocean Shores, Washington Join Date: 01/25/2009 Posts: 280 Rally Car: Can't decide which to use... |
Sean, Taking your car to the scrutineer site at Olympus was not terribly comfortable, I could have used about 5 or 6" more leg room... ![]() Next time we get together, I'll put you in my Capri, in my seating position... ![]() SteveL This is the point in the killing spree when you really should turn the gun on yourself |
Doivi Clarkinen Banned Godlike Moderator Location: the end of the universe Join Date: 02/12/2006 Age: Ancient Posts: 1,432 Rally Car: 1980 Opel Ascona B |
Sliders are used all the time in endurance racing. LeMans racing, Grand Am, etc. FIA has no problem with them. For example, Patrick Long and Joerg Bergmeister have been a driving team for several years. Pat is a little munchkin with a huge noggin, Joerg is a tall, lanky german. When you're doing a quick driver change during a pit stop you have to be able to slide the seat in that situation.
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Nate.Vincent Nate Vincent Professional Moderator Location: Pomfret, Ct Join Date: 07/29/2014 Age: Midlife Crisis Posts: 29 Rally Car: BMW 318ti |
This happened at the last AER race. Bad crash driver was brought to the hospital with fractures in his feet. There is a lot of discussion on the sliders and a lot of pictures/failure analysis.
https://www.facebook.com/272CrashInfo/ In my opinion I don't see an issue with sliders but I feel they make is harder to implement basic safe/strong fasting. For instance you don't have much room for thick larger diameter washer to distribute the load. Recaro has this now too. It's worth looking into. ![]() |
wvonkessler Wilson von Kessler Elite Moderator Location: Lookout Mountain, GA Join Date: 02/28/2006 Age: Possibly Wise Posts: 1,127 Rally Car: Colts are in Finland; now '87 325i, '89 325i |
Endurance racers also use different seat inserts that are dropped in for each drive in a fixed seat. Seems like a better solution. OTOH I've actually modified VW golf seat bases to fit bottom mount racing seats in th past.
"Talk about drugs. Driving a car like that, going that fast, it’s like all the drugs at once." - Tommy Byrne "Now, Pinky, if by any chance you are captured during this mission, remember you are Gunther Heindriksen from Appenzell. You moved to Grindelwald to drive the cog train to Murren. Can you repeat that?" - The Brain |