I want to build a +4 chassis. How much steel do I need? What substantial variations is the +4 chassis from the book chassis? I finally found a well priced steel supplier in the area so i just need to know how much 1" and 3/4" RHS tubing i need overall so i can buy a bit more than i need just in case. Also is it necessary to have seamless round tubing for the control arms? or is a welded one ok?

welded is fine, just do some research into what causes them to fail and what sizes are needed. If designed well, 25x2mm is often adequate.

ok cool thanx bro

I used 60mtrs of 25*25*1.6

u used only one size tubing for the whole thing?

Pretty much. I didn't use much 20*20 at all just a few cuttings I'd picked up. Ihave'nt done the rear section from the b/head back yet though. As mine's is also a 442 i figured that it'd be a bit stronger using the 25 and as it was already 4 inch wider I'd only be losing 3/8 inch in the tunnel with.

Oh and I used 25 O/D by 3mm wall seamless for the trailing arms and wishbones. (Big overkill when I seen them finished)

[Edited on 2/6/06 by omega 24 v6]

hmm that just might make my life easier cuz the steel gets a lot cheaper as i buy more in one size. Also i think i would like to have a beefier chassis if possible since i am putting in a 2.5L straight 6 m20 out of a bmw e30 325i, who would pass up that for only $150! thanx to a buddy of mine. Anyway thanx for that info i feel more confident in buying the steel.

good thinking there, with a beefy car engine you dont need to worry so much about the chassis weight. Im using a bike engine so weight is crucial, hence im using mostly 19mm round and 13mm bracing, with just a few lengths of 25mm round thrown in.