So same problem with the cutout open ?
the 3" exhaust will def be killing some power.

All you can do is check hot and cold side for boost leaks, no luck there....
try a heavier spring.

 

Its a tad higher with the cut out open. So could this really be a back pressure issue? Its a good size turbo with a 1.32 ar, I thought I would have lower back pressure than last years tc78 with a .96 setup.

 

I was thinking back pressure after the turbo not before.

But if its no better with cutout open not so sure...

try a heavier spring in the gate.

 

ater running the comp on the supra vs a gt35r, we found that the turbo just required more drive pressure with the big housing and wheel. 10# spring would make 7 or so, 18# spring made 16, but a 25# spring made 32. The wheels are just big enough that with the large housing and 79 turbine it seems to spool quick, but just wont light off without a bump in airflow, or a higher drive pressure. once it gets going though it really goes over the top! start leaning on it and see what happens

 

That's so weird because if use the boost controller it will make 10 psi just as fast as the 6lbs going off the 8lb spring. So it can make the boost I just think the waste gate is opening to soon.

 

Ok so I have a tial 38mm not a 50mm. It has a 10lbs yellow spring in it. So that means last years setup was doing 8psi on a 10psi spring and this year its 6psi on a 10psi spring.

Could the spring have worn out? I ended up putting a red 11.6psi spring in and it felt alot stiffer and was shorter than the yellow.

I won't have a chance to test untill tomorow.

 

Tial said that a 38mm waste gate is way to small on that size engine and turbo setup.

 

yes it is a bit small,
but i would have thought you would have been getting boost creep or overboosting from too smaller wastegate.