I have a 97c5 408with ls3 heads and intake. Hinson turbo kit. With a t76 turbonetics turbo .96 a/r a&a air to air intercooler. It also has tial 44mm wastegate and tial 50bov. It has a turbox's manual boost controller on it. I just purchased the car a few months ago. And yes I know the turbo is small. But the problem im running into is in first and 2nd I have 12 pounds of boost. And 3rd it jumps to16. Im shooting for 14#. So I try to turn it down now I get 10 in 1and2 and 14.5 in 3. Why am I getting different boost between 2nd and 3rd?

 

to much back pressure ? to small a wastegate ? has it always done it or more recent ?

 

Just got the car. Trying to figure it out myself..lol

 

Bump ttt

 

more load in higher gear can cause this issue, higher load=more resistance=more boost.

 

Regulate the boost pressure directly off the wastegate spring and see if it still gives you the same problem. If it does then I would suspect the wastegate is not large enough to control the turbine speed with that cubic inch. It could also be the angle at which the wastegate is mounted.

 

So to regulate off waste gate spring. Just remove the mbc? And see if the boost is the same in each gear? Sorry for my ignorance. This is my first Turbo car.

 

Be sure to run a vacuum line from the manifold to the wastegate bypassing the boost controller. Watch the boost when you get on it to make sure you did it right. It needs to see manifold pressure, or it won't open.

 

Id be worried about gate size with the placement on the hinsen setup. The hinsen setup only regulates the exhaust from the drivers side manifold. You may need to step up to a 50mm or even a 60mm gate with the location. Or add another 44mm on there.

Jay