ARP accessory studs for race seat mounting
 

I love my Recaro Profi XL seats, I have them floor mounted and all the way back. It is perfect for me and I love it, but I hate fastening the two rear bolts which are hard to start especially with my tunnel side harness and seat belt receptacle pushing on the center console. I decided try and find some studs but I couldn't find any good class 10.9 or 12.9 double ended M10x1.5 studs. I could barely find any fully threaded studs either.

I was poking around and found these ARP double ended accessory studs with M10x1.5 on one end and 1.25 on the other end. These worked out great with the addition of an extra M10 3mm thick washer.

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Thread chaser, an old bolt for comparison, and the studs.

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Since I floor mount my seat all the way back, I used them in the back. If my seat was floor mounted more forward, they could be used in the front.

When I change my harnesses next year, or if I have take the seats out for any reason, it will be a breeze :-)

My passenger seat is on sliders so I will probably keep them that way, even though it does look a little silly with one seat being higher, but it's not too bad....

Are these studs as strong as the OEM bolts? I believe so based on my research, the ARP site has info on their studs and best I could tell from the tiny bolt head markings, the OEM bolts are class 10.9.

Tight quarters behind the seat.

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Seats installed

http://986forum.com/forums/uploads02...1581794623.jpg

Fwiw, those threads are not standard 10x1.5, so be careful there

The stock bolts are tapered at the ends but I believe the threads are M10x1.5, I have used class 12.9 M10x1.5 socket head bolts to replace a stock bolt when the head was all messed up and I could hand thread it all the way down.

I sure hope that isn't some custom thread that is merely close to M10x1.5 as that isn't the spot to skimp on safety :cheers:

996SeatInstall

I copied and pasted the key point below. Less of an issue with studs but still

This seemingly innocent little fellow is a factory 996 seat mounting bolt. Other than the fact that it has a 6-point external head, and a "self-centering" tip, it doesn't look much different than most bolts.
Looks are once again deceiving!
This car came to me with "regular" 10mm x 1.5 thread pitch grade 8.8 bolts in place of most of these OE bolts. Inexplicably, two of the OE type were still used in the passenger's seat. I noted that the replacement bolts did not seem to move particularly freely in the holes when I took them out, and that the threads were slightly rounded off on their edges. I ran the threads with a die, and the situation did not seem terribly urgent.
I had the seats in and out at least a-dozen-and-a-half times trying to get all of these Big Problems worked out, and by the time I could see the light at the end of the tunnel, I suddenly found that I had
concurrently reached the end of the life span of the threads in the floor!
This on top of everything else?! #@%&@# !!
After the shock wore off, I got to looking at these odd little bolts. I tried to clean one of them up by running the threads with a die. It lurched in a tight-loose-tight rhythm. Strange. I threaded it into my finger tips. This does indeed not have a regular thread! It is sort of triangle-shaped. A trip to the local pro fastener outlet put order to my findings. These bolts are not normal, not even self-tapping. They are THREAD FORMING BOLTS. "Triodal" by name, if I remember correctly (?). The holes in the car floor are blank inserts, and these bolts, with their self-centering tip and special shape form their own threads as they are FORCED into the holes in the floor. These are not normal threads, and only work to whatever degree that they do with the OE bolt in them. Other bolts will not quite interface well with them, and if they are asked to come in and out too many times... POOF! Goodbye threads!
Oddly enough, the failures only occurred on the front holes. The rear threads remain rock solid. ???
Problem solved by drilling out the inserts and re-tapping them to the next closest size... 1/2"-20 SAE.
REAL THREADS this time. SOLID!

Yikes! Well I hope that I am under that limit! Very interesting and thank you for sharing!

Yes, I've noticed that during my numerous repairs and modifications that one can't assume that all those Porsche bolts can be swapped out with a Home Depot equivalent! Ever pull a transmission? Now why do they do that!!?

Thanks....please post your retrofit info. I will really limit how many times I remove my seats now

The studs are the ARP M10 X 1.25/1.50 X 48mm, SS, I bought the 4 pack which was kit 400-8008.

It comes with a 5 mm washer, but you may need to add another M10 washer depending on how thick your rails are.

The stud has an allen head but I recommend using a pair of M10x1.25 jam nuts, I got a 2 pack from the hardware store for less than $1 I think.