Some free advice based on computer analysis using finite element techniques:-
(1)weld in a panel between tubes E and LD (across the "base" of the front suspension mountings).
(2)weld in a diagonal on each side of the chassis from the top of tubes LA/LB to the bottom of tubes FU2/FU1.(check steering rack clearance!!)
(3)weld in diagonals from the bottom of tubes LA/LB to the mid point of tube LC (a V brace across the front of the chassis)
These simple mods increase the torsional stiffness from a barely adequate 1400ish ftlbs per degree of twist to about 2100ish. A further improvement, up to 2700ish ftlbs per degree is realised from welding in the top of the transmission tunnel from tube O3 to tube P. All figures are approximate as so many of the chassis pictures in the book have slightly different designs!
These are all well worth the effort as this sort of torsional stiffness improvement should make a noticeable difference. If anyone knows how to get in touch with Ron Champion I'd like to know as I'll send this info on with a diagram or two.
I hope this interests you all. Does anyone have any other thoughts on this issue?

Hiya,

I'm not sure if your aware but the Aussies on TOL have done a lot of stuff on improving the strenght of the chassis. The mods are posted in the files section. As i recall they fully weld the bulkheads and add an additional brace from the top of the engine bay to the bit you weld your engine mount to (i haven't got the book infront of me).

regards,

Mike

Interesting info, I'll certainly look into these mods.

Thanks!

James

Hi , The Aussies also make an inverted "v" at the front which I think is the same.
See Rob Lanes site as he has just done these mods for his Toyota conversion, and I have done most of them for my MK /toyota build.
Dean C.

[(1)weld in a panel between tubes E and LD (across the "base" of the front suspension mountings).

Did that - isnt that in the book?



(2)weld in a diagonal on each side of the chassis from the top of tubes LA/LB to the bottom of tubes FU2/FU1.(check steering rack clearance!!)

Didt do that. What I did do was weld in another 'criss crossed' diagonal in opposite direction to TR1 and TR2 cos to me that area just looks way too weak as standard. Would be interested to know what that does on your simulation. I welded 25mm tubes in - as they pass at the cross over point there is about 10mm gap between them which i welded in with a sliver of 25mm box section.



(3)weld in diagonals from the bottom of tubes LA/LB to the mid point of tube LC (a V brace across the front of the chassis)


Thats been mentioned on TOL before, but will tend to restrict air flow a tad. I have other bracing in that area as well.

A further improvement, up to 2700ish ftlbs per degree is realised from welding in the top of the transmission tunnel from tube O3 to tube P.


I welded, fully, a big oblong panel the whole way across. Then my car is built for touring and not for minimal weight speed runs!


atb


steve