Harnesses and seatbelts

The Oily Bits S1 Specific Topics
1

Apologies in advance for a bit of a DPM - I’ve searched the various Wikis around and the archives and cannot find what I need.

To those that have harnesses and seatbelts fitted together, how ???

I have 340R seats on standard S1 frames (there’s a slight difference between S1 and 340R frames, but I don’t think that’s the problem). The threaded inserts moulded in to the seats are too deep in the seat, so the bolts will not engage the first thread. I daren’t push the bolts too hard to start the thread as I won’t be able to tell if it’s cross-threaded in the insert. It’s down to the width of the rolled side of the 340R seat, and the thickness of the harness material. If I can get the bolt started, both will compress as I wind the bolt up.

I’ve talked to the Motorsport folks at Lotus (Ady and someone else) - they’re aware of the issue with 340R seats but don’t have an answer.

I’ve searched Ebay for longer bolts with no joy. Note, I don’t intend to have a longer bolt protuding from the seat, just need it a bit longer to get it started. There’s plently of space inside the insert in the seat before the end of a longer bolt would push through the seat cushion.

EDIT

Harnesses - Schroth Profi II Elise ASM
Seatbelts - standard

I’ve got one of the MSAR fitting kits but this won’t fit the 340R seat in a standard S1 frame.

Other option considered - as per Eliseparts - bolt harness lapbelts to floor - won’t work as the lapbelts aren’t long enough (especially on the driver’s side) to reach the crossmember, and it puts a permanent twist in the belt fabric.

Fix lapbelts under the rear of the runner - not sure that’ll reach either, and not happy with that size hole on an M8 bolt.

Thanks all !

2

Dobbo are you local to Lichfield (from MLOC?), let me know the length of bolt and I’ll check with our suppliers tomorrow?

3

Yep, that’s me.

I think I can fix the problem if I can get 4off 7/16 UNF (SAE) countersunk socket head screw, I can get part of the countersinking pared off, leaving a radius in the corner. I’ve shown the bolt around loads of folks at work and they reckon that was how it was made anyway.

Ideally, if I could get 1/2 dozen at 2 1/2" long, I can have a couple of practice goes to see what length I actually need.

I can see them in the Unbrako catalogue, but cannot find a supplier. I’ve emailed them but no reply yet.

Ta !

4

I’ll ask the question tomorrow mate… be in touch

5

6x 7/16 UNF SAE Countersunk Socket Head Screw 2 1/2"…I’m being asked for “Threads Per Inch” (TPI)?

6

Surprised at them asking that - even if the bolt length is strange, the thread isn’t. 7/16 UNF = 20TPI.

I have a source now, at 5mm longer than the current ones. That should sort me out, thanks !

7

Well all’s well that ends well…I did put it into someone else’s hands As long as you are sorted…

8

Hopefully !

Thanks for your efforts.

9

Surprised at them asking that - even if the bolt length is strange, the thread isn’t. 7/16 UNF = 20TPI.

I have a source now, at 5mm longer than the current ones. That should sort me out, thanks !

Turns out they were a little foxed as it’s not something size wise WE usually order…it was there way of asking “are you sure” lol. Any probs let me know mate.