I'm currently rebuilding my s4 engine with a Half BP. My question will I boost creep with my bnr stage 1. Another guy with an rx7 said I would because of the half BP. I'am planning to get a gt35r sometime in the future.

 

Assuming you have a full free flowing catless exhaust without a airflow meter you most definitely will. As long as you have enough fuel and you can keep your intake temp charge cool all you will do is kill your turbo before your upgrade...

 

a half bridge is a lot to ask of from an internal wastegate, especially if it's an S4 hybrid because they only bleed off one runner.

 

Do you think it will go pass 15psi? And I do have the supporting mod (fmic,rteck2.1,720secoundary). Would a t4 with a 1.15a/r give me crazy lag?

 

In the higher gears 4/5th if its cool out you will probably see more than 15psi. As said the s4 turbine housings internal w/g are terrible. It is hard to say though, no one runs a HBP on a stockish turbo, it just doesn't work...

It depends on the size of the T4 1.15's compressor if you will have a lot of lag, in addition to your exhaust size, engine condition, tune etc.

If you run a 4" exhaust a 1.15 P trim up to a 67mm turbo is surprising very quick in response on a HBP.

 

A half bridge on any small turbo is going to turn it into an on/off switch. I've tried half-bridge on a stock sized hotside and it would hit 15 PSI before the pedal was on the floor at 2500 RPM. It was a waste of a turbo, and a waste of a port job.

Run a man sized turbo on a half bridge. TO4R, 4088R, etc.