How well do the Sparco (or other) heavy-duty seat sliders hold up in a bad crash?

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.

Here's the recently clarified SCCA rule regarding the use of seat sliders in a road race car:

4176 (CR Clarify 9.3.41
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?

I personally feel sliders should not be used in any race car. I can't imagine they would be strong enough without being heavy and bulky.

I can un-bolt and re-bolt in my seat in 2-3 minutes.

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.

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

I agree with Gene. The seat really isn't going anywhere. I also remember the Sparco sliders being very heavy duty the last time I installed a set.

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Robert.

"You are way too normal to be on Rally Anarchy." Eddie Fiorelli.

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.

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" has a problem on stage and someone else needs to move the car. How you gonna get a 6'4" worker into that fixed seat in a rally car to move it? It is something to consider.

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.

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heymagic

Lets say a vertically challenged driver (5'4" has a problem on stage and someone else needs to move the car. How you gonna get a 6'4" worker into that fixed seat in a rally car to move it? It is something to consider.

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.

Thanks for the feedback. Good discussion.

Personally, I feel very comfortable using sliders in my road race car. They were nice to have in my old rally car.

Anyone going to post any links to some sliders?

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phlat65
I personally feel sliders should not be used in any race car. I can't imagine they would be strong enough without being heavy and bulky.

I can un-bolt and re-bolt in my seat in 2-3 minutes.

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... We'll see if you can reach the pedals...

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SteveL
This is the point in the killing spree when you really should turn the gun on yourself

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.

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.

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.

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