Mark in Baltimore

Hello all,

I know there's no way I'm breaking any new ground here, but I can't find a single post on the racing board regarding how to mount a Recaro Pro Racer seat into a 993. I've read a few posts where John Hajny says it can be a challenge to put these things in, but, four years ago, I mounted my GT3 seats into my car in less than three hours, so my expectations were high.

Here's the scenario: new Recaro Pro Racer HANS (regular size), Sparco sliders and Recaro side mounts (the steel ones with the big "RECARO" on the side. It appears that the fit is 20mm off. Are people putting 10mm spacers in between the seat and the side mounts to make up the difference?

Why am I using the Sparco sliders with this application? Respected cage builder Mitch Piper (http://pipermotorsports.com) used the Sparco pieces for my GT3 seats since they were about half an inch lower than the stock Porsche sliders I was using (my head used to touch the headliner; not cool), so I'd like to retain them. Besides, the fitment problem has nothing to do with the Sparcos since they are perfectly inline with the Recaro side mounts, unless, of course, a Recaro slider is offset to move the holes outward.

It looks like my only recourse is to use longer seat-to-side mount bolts and put a 10 mm spacer in between the side mount and the seat. Any ideas here? If spacers are my only solution, where can I get them?

As always, thanks for any help!

Greg Fishman

I did spacers in my 993 when I had a similar issue. Had a machine shop fabricate some nice aluminum spacers, not a big deal at all.

Wreck Me Otter

I had spacers with all of my Recaro seats.

Mark in Baltimore

Thanks, guys! That's the conclusion that I was coming to. I'm going to have to temporarily use four fender washers. Where can I get the extra long bolts? Lowe's/Home Depot?

Larry Herman

Lowes has some very nice 12.9 spec metric flange bolts made by Hillman. Much nicer than socket head bolts and you can easily tighten them with a box wrench when they get loose.

Mark in Baltimore

Thanks, Larry. I hope they'll be long enough.

BTW, what's 12.9 spec?

Marc Shaw

I suspect he means Grade 12.9 (a measure of bolt hardness).

Marc

Mark in Baltimore

Thanks, Marc.

CWay27

Go with the spacers, it will be easier and cheaper but there are side mounts, with larger base and sloted holes that allows adjustment related to seat width.

RedlineMan

Hey;

Using spacers is a compromise that I try and avoid. The only concern I have with using spacers is to make sure and maintain a decent amount of bearing surface between side bracket, spacer, and seat.

With a side bracket mounted directly to the side of the seat, you have the maximum bearing surface offered by that particular bracket being utilized. With any spacer, the bearing surface is reduced to only the size of the spacer. Further, moving the side bracket out away from the seat creates increased leverage working against this union of components.

If the spacer is of small diameter, it will transfer any rocking/bending force into a very small area of the seat shell. Of course a lot of the force is taken by the thread insert in the seat. However, the more bearing surface a spacer has against the side of the seat, the more force will be spread into the seat material surrounding the threaded insert. This will have the effect of lessening the load on the insert/interface itself. Anytime you can spread load, it is a good thing.

Mark, I think you're beginning to see why I usually end up going custom. I get a perfect, compromise-free installation.

Larry Herman

Actually what I meant was Class 12.9, which is the metric method of bolt hardness as opposed to our "grade" specification. IIRC Class 8.8 = Grade 5, Class 10.9 = Grade 8, and Class 12.9 = Grade 10.

Mark in Baltimore

CWay - Thank you. Do you have any links to any vendors?

John - Thanks for your detailed answer. I know, I hear ya. It's a concern of mine. I'm not crazy about a spacer, although it seems to be what other people are doing. How are the pro teams handling it? I see the Recaro side mounts on their seats in 911's. I'm going to have to temporarily use a spacer until I can figure out who makes a proper, off-the-rack side mount, if such a thing exists.

What do you think is the minimum diameter I should go with? Is 3" too small? What about shape? Is round best? Square? Hexagonal?

Larry - Thanks for the info. I'm off to Lowe's this morning to see what they have.

Wreck Me Otter

Get a couple of 10mm think aluminum plates and drill holes in the appropriate locations and mount on the inside of the adapters.

CWay27

Mark, I don't have any vendor in mind but the side mounts described are available from Sparco, OMP etc.

Here's a picture of sparco side mounts from Demon tweeks.

BTW, did you try mounting the mounts inside out, meaning the recaro script would facing inside?? Pictures from the carrera CUP(1992) registry, shows that atleast one side was reversed to center the seat with pedals.

chrisp

When I purchased SParco seats about 4 yrs ago they spec'd a spacer between the seat and side mount. I think they wanted 3 sq. in. of surface (or whatever the metric equivalent was). Point being Sparco wanted spacers and weren't concerned about bearing load.