i,m building a book chassis,intend using triton seats,looks like the top mounts will have to be raised above the "o" tube,anyone know by how much as i dont have seats yet and what have peeps done to raise mounts?

Seat Belt Mounts 3


Pre SVA Prep 2

cheers andy,round my way that would fail,think they have to be a tube that goes through the horizontal bar.i,m looking at mounting them on top of "o",if no joy i will have to do it your way

had mine from luego(rip) but think tube engineers ltd made their roll bars etc as i just recieved my exhaust from there, was alot cheaper than luego quote! the mount are in the crossbar with some nice threaded dowels to be welded in. aint got any pics of the mounts but will try if you like.

oh well looks like roll bar mounted then,i know how to do it thanks,just didnt want to go that route

John,

I've got mk high back fibreglass seats and did mine like this to get some extra height on the mounts:
http://www.locostbuilders.co.uk/upload/cockpit%20bulkhead.jpg

I welded the threaded tube to the extra 1" piece before i welded them onto the top rail.

Ned.

that was my plan ned,where you get threaded tubes?

made them up on a mates lathe, though they took bloody ages! i'm sure most kit manufcaturers can supply them, mk, mnr etc etc etc

Ned.

John, I also used a crossbrace made form 25*50 box with a crush tube inside and a threaded plate on the underside, passed ok.



Pre sva 07


cruchtube

ATB Dan.

Ours are made of solid bar, drilled and tapped then welded quite solidly to the bar behind the seats.

I'm concerned a bit by the last setup. With the force of the belt applied several inches above the tube I'd expect the tube to rotate in an accident, adding several inches of unwanted slack.

Er. It's designed so that in an accident the tube will twist and therefore reduce the 'jolt' on the occupant.

Since the belts are designed to stretch up to 3" on their own, the total stretch including your twisting mount may allow the driver to impact the steering wheel. Since the belt manufacturers specify belts be mounted to hard points (in the literal sense) that seems the right thing to do. They've done crash testing and I don't know enough about impact deformation to second-guess their advice. How do you know your addition works safely, do you have crash test data to back it up?

[Edited on 5/7/06 by kb58]

dont be daft kimi, if he'd crash tested it the car wouldnt be there!

New cars often have deformable mounts, to gradually give slack and to spread the impact out a little. Obviously its not a great idea trying to predict what happens in an accident without testing and modelling, but if thats how he wants to do it...

I have crashed it once and the mounts didn't twist The steering rack came off and part of the front suspension needed cutting out and replacing though