Has anybody tried this ?

I'm modifying a Pre-lit Westfield to take an RV8. The engine is no problem, cut out the "R" tube and inserted a couple of "Y" braces (all be it a bit shortened).

But the LT77 gearbox housing is f*^&ing humongous and has eaten up a lot of the footwell space for both passenger and driver.

I've solved most of it by shifting a few of the tubes (as I understand it the tunnel ads very little to the strength of the overall chassis), but would like to add a bit of stiffness back by way of triangulation.

Room is at a premium (should have started with a better donar or built from scratch - too late now); but am I correct in thinking that a triangle of any kind is still a triangle no matter what it is made out off?

I can't get any more tubes in, but I might just be able to get some wires!!

Any thoughts?

the transmission tunnel doesnt have much affect on chassis twist, compared to the sides of the car (the tunnel is too close to the axis of twist down the middle of the car) but it is more equal in terms of bending front to back (ie pressing down in the middle).

Myself i wouldnt bother with spokes etc cos i dont know sod all about them! Id just weld 13mm 16g tubes in as X's in all squares, and make it all fit round the box.

I'd try/do this..
Balls, it's too big. Do a search for cytriks. He did a full fea evaluation and how to strengthen it all.

[Edited on 28/6/06 by DIY Si]

Its just a thought.

Afterall the old biplanes like the Fairie Swordfish and the Sopworth Camel didn't do too bad with this form of technology.

And how many bike wheels collapse?

I would think that if you can get all that radio mast support gear into the space, then you could easily get some 12mm RHS in instead, and that would work. Alternatively you could just weld a plate over that area, I believe that would be classed as triangulation, (of a type). Chippy

Plate is an alternative, but damned heavy compaired to a bit of wire.

Once you have the crush strength of the 25 x 25 x 16swg tube, the rest is just stiffness - no matter how it is acheived.

I could get in some thin tube or rod, but surely tensioned wire is a much more elegant solution?

The only problem is not having the compression strength of having a tube/bar. Fine in tension, as the wire is already there, but once that tension goes you've just got wires flappping around.

quote:

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Originally posted by DIY Si
Fine in tension, as the wire is already there, but once that tension goes you've just got wires flappping around.

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Look at the Aussie mods. http://locost7.info/mirror/aussiemods.php

This is what I suggested to someone who had a 302 in a LC. The tunnel can be a structural member by making it a tube. Get a stick of 1x.5x14 gauge hrs. Replace the floor pan with 16 gauge steel if alloy and fully weld. plate the top rail from firewall to front suspension with the tube and stitch weld, do the same on the bottom of the bottom rail all the way to the rear sandwitching the floor pan. Install a down tube from the roll bar, it does have a roll bar, to the firewall/floorpan. Though this is a bit of work it should considerably stiffen the chassis with out adding too much weight.

[Edited on 29/6/06 by locostv8]

Use tube rather than wire/bar. It will still add stifness but weighs next to nothing