I want to stiffen the trailing arms by adding the 1" tubes as outlined in another thread http://www.914world.com/bbs2/index.php?sho...p;#entry1831183 . Erc had some good info on this as did Andy (socalandy). This is my question. Should the tube wall be the same gauge as the trailing arm material? Andy stated the the tube he used is .125 wall and I thought that was overkill but I am a self admitted dumb ass and what do I know. Also, should the tube be chromoloy? The only .125 I have is mid steel sch. 40 and thought I'd better ask those in the know, first. TIA, kent

This is a guess - but I would imagine that any tube would be sufficient (within reason).

Skipping any structural issues as I am sure others have more insight than I do. But it is always best to put the same types of steel together. I don't think the arm is chromoly so I think the mild steel might be the better as it will have similar expansion and contraction properties as the arm. But I don't know if the way that loads are carried through the makes a certain wall thickness a requirement but it would seem appropriate to try to match what was there and not go into overkill mode unless there is a clear benefit.

Are you going to reinforce you suspension mounting ears?
Are you going racing or autocrossing with the car?
remember the trailing arms are designed to bend on impact and absorb energy, once they are stronger the energy will be transferred to the car body.

God point on similar metals. I would think the tube would be somewhat larger and that the shear strength of the tube would have to = the tensil strength of the metal on the trailing arms. If this is confusing I can re-explain it and confuse you again.


No. No racing or autoX. I'm not saying the car won't develop a taste for an occasional rice rocket. I've done the Engman kit going the suby 6 route. I'm keeping it narrow/4 lug/ 1 mirrored sleeper.