Tubular seat rail installation

yeh valid, i think the concept is that the bolts have a shear strength though, the idea being that the seat wont destroy itself in a crash. Although, having spoken to some seat people they have said that shelled seats are designed to crack in an accident as a form of impact absorbtion.

 

Interesting info gofaster - have you got an FIA book, or pdfs?

 

i haven't personally, that came off the british rally forum. Seat rails have been debated far and wide on there and thats the drawn conclusion

 

I've been using this thread the last few nights to fit my seats, its been a great help chaps!

 

is all that fab required just to have it remoavable, a weld would be arguably stronger, no?

another thing, the info that came with my TRS 6 points, said the crotchstrap should be within 20 degrees of verticaly down from the hole in the seat?

I was under the impression that they should be attached further back than that, or can i go out of the seat under the front rail and then back to the hard points?

 

Debated a few times but always a difficult one - let me dig out a diagram from another thread.

 

Makes for a squinty read, but here it is, from earlier in the thread. It doesn't actually prescribe an angle, simply saying 'rearward'.

 

Got it - FIA diagram, courtesy fthaimike - mentions the 20 degrees...

Might be worth a thread tidy and new FAQs on:

- harnesses
- rear harness bars
- tidy of this thread also

?

 

Interesting how the belt manufacturer (Willans) and the FIA differ on the angles of the belts - I`ve followed Willans.

 

It is indeed. Anyway, there's some good info here - I think we've got enough for a harness thread and a tidied seat rail thread, as I've got some tube data also which I can add now, plus some seat tag outlines which I can scan up which people could copy easily.

Overdue PM/email reply owed to you Andrew - will get on it!

 

never really thought much about crotch straps anchor placements. always assumed that they should be rear mounted. if they were mounted in front i can't see how the strap could be tightened and 'restrain' the body in a crash. if this was the case there would be movement of the body before the belt took the load force. (a similar movement to the submarineing the belt is designed to stop.) load on the belt could also be transfered to the seat depending on the position of the anchor point.

tempted to put in some tubular seat mounts over winter. only issue i've got is getting a decent seating position. it's tough being a short ****. might order up the bits and do it over xmas period.

 

What was the final out come for seat tubes. To punch or not to punch the transmission tunnel that is the question.

Or just spreader plates both sides. Also the hole in the spreader plate as per Steve R's post. So the tube directly fits to the tunnel?.

Cheers

 

I think it is personal preference and cannot see a clear reason to do it one way or the other.

Tunnels are thick metal anyway, so it's based on a load of assumptions about the guage of that, the guage of the inner sill etc.

Having done the seat on page 1 in July 2006, had the interlude of 3 years and looked at various cars, I did my current Mk1 with complete spreader plates last summer.

I must sort a new thread at some point with all the info concisely together.

 

Using Steve`s pic

Is there a reason NOT to weld an L shaped piece of 2mm plate onto the floor and to the seat rail ? in effect tying the rail to the floor ?

Where I`ve marked in RED.


Not sure if it would add anything worthwhile, or if, for the sake of a small piece of plate would help in some small way? I`m asking as by removing the front OEM wide mount, you are have removed that link between the floor / tunnel and cills.

May be no benefit whatsoever, but thought I`d ask

 

Funny, as I was browsing this thread too. Lol.

I see where you coming from Nige, but not sure if it would make any difference?

Gurds

 

me neither, but thought I`d ask

 

Certainly the FIA / MSA don't ask for this.

It could have a small torsional benefit, through effectively tying the sill to the tunnel, but ideally could do with being attached in several places to achieve. Even then, it's still just floor tin.

Requires advance planning of crotch strap fittings / belt runs obviously.

 

Maybe it depends how much you weigh

 

Ah the "telly tubby upgrade"

 

more hassle than its worth then.

Thats fine, just thought I`d ask. I`ll be using box section for my rails I`m fitting, why do people use tube instead ? (although I see some do use box)