Stupid BNR questions
 

As I research possibly going BNR this year I'm left wondering one thing. If they are reusing the turbos and I have the first gen turbos NA31 or whatever it is, wouldn't the BNRs be prone to the same cracking as the OEM turbos or does he use new exhaust housings with the higher nickle content?

I would think (hope) they use more recent castings than the old circa 1992 ones.

Mazda upped the nickel content specifically to stop cracking in the castings in later years. That was for stock twin turbos. You would expect that BNRs, being high performance, would use the best grade possible for their application...

yes they're prone to the same cracking. bryan re-uses whatever core you give him. if you want the newer manifold, send him a newer one.

I would say they are less prone to cracking than the original because most the people that will run the BNRs will not use a precat and may not even use a cat.

On my FC TII S5 BNR Stage 4 turbo it had some cracking when Bryan built it in 2001.

With the combination of larger exhaust wheel and taking out the precat/cat the cracks have never spread.

It has seen lots of racing and gotten so hot that the divider between the runners in both the manifold and the turbo near the flange has sagged over toward the rear (front runner has bend in it but rear runner is straight shot).

Hmm, if I'm going to dump that much money into rebuilding them, I don't want to gamble that they may crack especially if he has to machine the exhaust housings. Are you able to just buy the newer higher nickle exhaust housings?

Contact Brain at BNR turbos.

Brian is awesome to work with. Give him a call. He doesn't use junk cores to start with.

you'd have a better shot contacting Bryan at BNR than you would contacting Brian or Brain...

lol

Well played good sir. Well played. :-)