Hi all,
Just a quick one, im helping to set my mates Greddy up atm and were having trouble getting the car to run 1.2 bar.
Basically the low setting works fine for 12 psi but the hi we wanted about 17.

Problem is it peaks out at 15 (an inconsistent one at that) and wont go any higher.

The car has been Gtech'd, exhaust, induction kit and PRV'd in the past and has run 17/18 psi no problems.

My initial thought was wastegate actuator but could this just back itself off over time and lower boost?

Phill

I've had the same problem. Low boost was easy to set and very consistent by high setting was just a paiiinnnn...

However, i did manage to get it to the boost i want..it just gets there inconsistently.

I'm aiming for 1.3 bar high boost and my actuator is a 0.8 bar ...So it shouldn't be a problem. I've checked everything related to wastegate but nothing was wrong..so i just left it at that

First thing i'd do is check for any boost leak. Check the pipes that go to the wastegate and also the housing. If thats ok, check the relation of wastegate opening rate and actuator arm pushing it. If you are not achieving the boost you want ( lower than what you are aiming for ) , then your wastegate is probably at its full aperture too early.