Any tips on fitting s type seats please?

[madmaninshed]

Hi, I eventually found some nice leather s type seats to replace the older seats in my 1998 car. They fit in well, but the old ones bolted through the floor chassis members, and the bolt positions are completely different. I want to fit the new seats correctly, and if possible, without drilling too many holes, so that the originals could be refitted if somebody wanted to. If anyone has done this, I would be grateful for advice. Many thanks, Paul.

[Wrightpayne]

There are strengthening channels riveted to the underside of the floor with the S types

[paul richards]

As said you need channels under the floor. I would also suggest tack welding the bolts to the runners to make fitting and tightening nuts easier. 

[Graham King]

I did something similar on a TVR recently, I put these on the underside of the floor so that the bolts went through something more substantial than just fibreglass (which is all they do on a TVR ). 

Aluminium Channels

Graham.

[alan c]

I did this a while ago now and from memory it is just possible to fix the Chanel's under the floor using the existing bolt holes then you need to drill new holes for the new seat mounting points. The Chanel's are also held in place with rivets, the chanel is pre drilled but you will need to drill through the floor. It all took some time to get aligned.

There was a thread on here a while ago and someone made up steel (I think) plates that picked up the existing mounts and lay inside the car providing a steel section running front to back that the new seat can sit on.

[madmaninshed]

Thank you all for your advice. The channels do seem to be the correct way to do it. However, if I carefully position a seat fully back in the cockpit, and with the adjusters slid forward, I could make a flat steel bracket about 74mm hole centre to hole centre for each front seat bolt. These brackets would be bolted to the original chassis mounts, and would lie flat under the floor to where the new wider positioned seat bolts will protrude through the aluminium floor. Similar longer flat brackets could be used from the new rear seat bolts to the original rear chassis seat mounting points. Using HT bolts etc, would that be strong enough, as it can be done by drilling only 4 holes per seat, and without delay or the cost of carriage and importing parts through the French customs?

[Jonathan Kay]

Please could you add a sketch of what you're considering.

Would it be possible to combine each of those new front and rear brackets so that they run the whole way between the two points where the load is injected into the chassis?

Jonathan

[alan c]

Jonathan

someone has done what you are suggesting but my searches for the old thread are not finding it

[Drumster]

See my Post #5 on this thread

[madmaninshed]

Hi Jonathan, Please excuse sketch. It is the first time I have used this software, and I have no idea how to draw curves.  The brackets would bolt under the chassis member at the front, and under the seat mount lugs at the back. Then the new seat bolts would go through both floor and brackets. Perhaps a continuous bar might be better as in Drumster's post.  

[Jonathan Kay]

What Drumster says and shows. Continuous supports should be lighter for any given strength... 

Jonathan

PS: It's possible to link to an individual post in a thread:

https://www.caterhamlotus7.club/forum/techtalk/rear-floor-given-way-drivers-side
https://www.caterhamlotus7.club/comment/2250548#comment-2250548

[Jonathan Kay]

"someone has done what you are suggesting but my searches for the old thread are not finding it"

!

Discussion of searching, and my preferred method.

Jonathan