928@AMG

Hello,

does someone know if its possible to fit sportseats from a S4 into a 1981 S Model ?

The seatbelt is fixed to the seat frame on the sport seats , but on the older S model the seat belt connector is fixed to the body .
Does the stock 1981 seatbelt fit to the seatbelt lock on the S4 sport seat ?
Can I use the stock screws to bolt the S4 sport seat into the car?

Thommy

linderpat

physically they will fit. the trick is with the electrics - making them work.

928@AMG

The electrical fitting shouldn't be a problem for me - one of my pals is a skilled car electrician with 928 experience .
Under the stock mechanical seats I have seen that there is already a small harness , most probably for the electrical seats .

I also know they will fit physically . The trick is - do they fit with or without changes on the floor body frame ? I want to use the M8 bolts from the S4 sportseats , not the smaller M6 screws from the stock seats .

joejoe

I put a set of '85+ seats in my '81, and wiring for power was not a problem. Mounting was easy as original seats. If you change bolts you will need different front nuts (the piece that falls off under the rail) I do not think you can change the rears. I used original for the car.

Landseer

I had a different experience.
Put 87 or 88 S4 seats into 84.

The mount rails in the mid year car didn't have the same surface profile as the bottoms of the S4 seat.

Seems subtle and immaterial, but I believe it isn't.

This translates into the bolts, whichever size, being positioned for shear.

With the original seats in the 84, and I assume earlier ones are same, if the car were in a collision the bolts are in more of a stretch position. As the seat would move forward relative to the base to which it mounts, it would lift out of the contours and put the bolts in stretch, not shear.

I think the S4's also have a mount plate profile, its just different, so the seats didn't match that of my 84. You may see it yourself when you go to set the S4 seats in-place, they will slide around and won't settle on the mounts. Earlier seats on early mounts just settle and stay put, so you can bolt them.

I used them anyway but it concerned me.

Electrics were easy. Mine were memory seats, I just studied them and wired the power directly.

linderpat

Interesting Chris. Based on your observations, I would be very reluctant to do the swap. The bolt shear issue would be a real concern for me. When it most matters is when you are in a high speed collision. These cars are very safe (see Willhoit story elsewhere on here), but if the one thing that fails is the seat shearing off its moorings and propelling the driver forward into the crumple zone or thru the windshield, then that was a bad decision to swap non-conforming seats. I would not knowingly turn a very safe car into a dangerous one. I would get different seats.