.96AR on a 7668

[forcefed3.8's]

Right now I am running a .85 Precision housing on my 76HPQ (68mm). I have a .96AR 4 bolt housing I can put on it. I am wondering if it is worth the effort. I am not worried about lag, the turbo spools fast with this engine, in fact some lag would help. I already have a Tial 44 wastegate I can run, I will just have to put a 4 bolt flange on the headers, and a v band flange on the DP, which I can do myself.
The main reason for this is with my new engine, even with a ported wastegate and a stock actuator with minimum tension, 25psi is as low as I can get the boost. My old 245" 8:1 engine with the same cam and heads that flowed slightly less would go as low as 18psi with the stock actuator and 21psi with a high boost actuator. I am thinking back pressure is high.

 

[forcefed3.8's]

No one has any feedback?

 

[bison]

I dont have any real data but I'd speculate the backpressure would be high even with a large a/r tang housing if you are getting over 900hp. You could still get a larger turbine in there if you want. Might want to look into that. probably only cost $300-400 if nothing else is wrong.

 

[forcefed3.8's]

Are you talking about an HPS 75mm exhaust wheel? I was thinking about either a 7675 or a 4276. I figure the 7675 would be better on the street??

 

[bison]

Are you talking about an HPS 75mm exhaust wheel? I was thinking about either a 7675 or a 4276. I figure the 7675 would be better on the street??

Yes. The 75mm HPS wheel is a turbonetics if I'm not mistaken. There is probably a new better wheel out there or about to be. Precision has been using newer wheels in their latest turbos. Its worth calling around to see whats out there. Its hard to get a lot of ex wheel in that cartridge. Garrett has some GT wheels that will get it done also.