89TurboII

I have a problem....I boost at 10psi and at bout 4500 the boost tappers
off till 7000 (ends at 4-5 PSI) its really pissing me off I'm going to check my BOV see if its tight and check all of my IC piping does anyone have anyother ideas....please help thanks.


nick

vaughnc

OEM Turbo ?

89TurboII

Yeah it sure is...........all I have is Full exhaust, APEX'i bov, walbro fuel pump and S-AFC

sortino

I had a very similar problem with my 89 TII with Greddy Profec. Someone suggested that the profec (digital model) doesn't learn the boost curve very well. The problem for me was intermittent. It shows up sometimes, but it goes through periods where it just seems to bleed off. Try reprogramming you boost controller if it is digital.

live4boost

iTrader: (2)

maybe the stock turbo just can't hold on for very long. Mine starts to drop off around 7k+ also. It goes to 10 strong but just can't hold it.

Felix Wankel

Mine will go to 12 with no boost controller, but it tapers off around redline down to about 9. I have a ported wastegate on my turbo.

live4boost

iTrader: (2)

oops I didn't see that it starts at 4500 and goes down.