I've done some searching but have not come up with a straight answer. Maybe someone with long term experience can chime in.

I'm in the process of building a manifold for my car, to mount my largish aftermarket turbo. It's a decent size, weighing about 35 LBs or so and thus I have been considering running a brace to the engine as I've seen others do.

However I've also read that the different expansion rates between the manifold and brace (we all know how much stainless likes to move) causes the very cracking problems that the brace is trying to prevent.

So who has braced their turbo? Any long term problems? Worth it?

 

its a very good idea to brace the turbo aarron.especially if your going top mount like most rx7 guys do.

 

Top mount intercooler? I have a front mount. If you are talking about turbo placement, I am keeping it as low as possible.

It does seem like a good idea at first thought but again, I have heard reports of the brace itself actually causing the cracking it tries to prevent.

 

i dont have any 1st hand experience on the subject, but i do have a couple of observations.

we had a chance to look at the racing beat 13g turbo motor(s), and the manifold runners are little bellows flex pipes. 90% of the weight of the turbo is held by a brace.

so it seems like a good idea, but the turbo needs to be able to move around....

 

I would say it's probably not nessasary as there are quite a few gt42's out there on manifolds that don't have bracing. I would think the best place to add the bracing would be on the manifold it self. For instance add a brace from the t4 flange to the runners, then add one from the runners to the exhaust flange and then one from the runners to the wastegate flange.

 

No one has first hand experience then?

The Racing Beat design sounds like a good idea, but that's a race engine and won't go through the kind of heat cycling that we would see on a street car. It may be acceptable in that case but after a year of use, cause issues.

I actually know someone who had their GT42 fall off of an engine due to a cracked manifold.

Bracing on the manifold runners themselves is probably the best bet but doesn't really help the issue in that the weight of the turbo is still on a huge lever.

Maybe what I'll do is run it unbraced and if it starts to crack, fix the cracks and then make a brace...

 

I connected my 42R to the water pump housing and used a double slip fit collector on the manifold to (hopefully) provide some margin for expansion. I still haven't started it yet though. I can't imagine supporting it with just the manifold runners.