Although fairly common, will i still be able to use this? Will I be able to get a rebuild done on them even though the manifold is cracked?

 

Yes and yes. Your talking about the cast iron piece that fits between the turbos right? Not the separate part that bolts directly to the block?

 

yep, i am talkin about the part in between the turbo's that you see normally cracked.

 

what if the turbo side has a crack on it...?? can it be welded back??

 

make sure you carfully inspect inside the manifold, look in there with a lite. i have seen a lot of cracks in there as well. there will be lost boost.

 

My machanic has a set BNR stage 3 and they had cracks . He is having them welded by pro that can pre heat the parts for a proper repair. He has had this done before with lasting results. He also has made a bigger wastgate door. and moding the manifolds . If you can not make a new door , the pre spool door can be put in the wastegate place, it is 1/10 inch bigger, then the port can be bored to 1.30 inches Take the hot parts to a good welder and a machine shop to resurface what is needed

 

The Mazda man was talking like the cracks inside the casting should be repaired lest the cracks grow and cause eshaust leaks at the gasket face. This is contrary to what I hear elsewhere, that cracks are common and just let them go. 1) How much cracking would be too much? 2) do they normally propagate and grow? 3) Is there any good way to repair cracks in the iron? castings, or would attempts make it worse? 4) Does Mazda themselves give any guidelines on this topic in the service manuals? Thanks