Help: Gt28rs, less power than the stock turbo


boost on the way!
Black Mica Mazda Proteg 5 2002
So i just finished the install of a brand new garrett gt28rs on my msp and went for a test drive to find its worst than my stock turbo...
Theres is definitly something wrong here.
I had the hiboost set up on my p5 with the ihivf22 which is similar as the gt28 and was a torque monster.
Feels like the potato is not spooling fast at all and was running 5-8psi and was not impressed by the power at all
Suporting mods are:
-Steedspeed exhaust mani
-Pope down pipe
-2.5 test pipe
-2.5 racing beat cat back
-forged wga
-gutted intake mani
-aem wideband truboost

I am running on stock tune and been running for the past 2 years at around 9psi with stock turbo

Note: after further inspection i found the vaccum hose from my boost solenoid to the wga collapsed, i changed it but never had the time to test drive again. Unsure if this could cause the issue.
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MOTM Winner Jan '09
Authorized Vendor
I ran a 28rs for awhile and didn't love it. I moved back to a 60 trim T3 and I love it. I've run many turbos in my car, and the T3 is the most fun.