Thread: Turbo psi lost at 6000rev

Hey Guys

I´m new in the boost world and I had just build a SR20VE-T with the next mods:

T28 ball bearing nissan silvia turbo (6 psi internal wastegate)
OEM DET Pistons
STI injectors
2.00MM cometic head gasket
Greddy profec a boost controller
OBD1 ECU with nistune chip

The first time that I visit the dyno I got 250 WHP with no problem at all at 9 psi (4th gear)

The second time I set it up to 15 psi and I got 300 WHP at 6000rev and I got a lost of power, the psi boost when down from 15psi to 11psi (4th gear) for no reason.

I have been driving it for a about 3 months already and I chance the boost controller. Now I´m using the apexi avc-r. The engine runs excellent. But the psi issue on 3er and 4th gear is still there. Now about 6500rev.


Now my question is: Is this happening because this kind of turbo can´t handle this power in high rev of maybe can be affect it because of the 6psi internal wastegate.



Thank you for your comments

PELO

im thinking its the internal wastegate , you need an external gate surely, also what kind of exhaust manifold you got btw?

I would agree that the internal gate is being over run. Usually a single port internal gate can only double the base spring pressure before it will bleed off boost. You can can upgrade to a waste gate that has two ports and that will hold more pressure. You can also modify the turbo and go external gate.

Yep yep... internal wastegate can be the first option...

I´m using GTIR OEM exhaust manifull and 2.5" down pipe and 3" the rest... No Restrictions.

a tubular manifold and external gate would be a very nice change