Kevin01

Hi,

Ive installed my new setup 2 days ago. Peakboost mani,3071r .63ar,tial 38mm (sr20det + other usual mods + forged). When i took the car for a test drive it wouldnt boost above .4bar. I said ok, its the wastegate spring, its a 7psi spring so lets change it. I take out the external wastegate out today, install a new 1BAR (blue) spring. I take the car out for a test, the car boosts only up to 0.7 - 0.8 bar. The wastegate is correctly installed, the top of the external is connected to the boost controller (profec b II) and the side one to a Tee-piece which is connected to my intake pipe. Ive tried using different settings on the bc only minor change to boost noticed. Ive tried turning the boost controller off(also bybassed it) , it still boosts to a steady 0.7bar.

Something else i would like to mention, the custom turbo outlet i have is 76mm through vband connected to a 3'' exhaust. There is no space for a bigger pipe. But i dont think the fact that it doesnt boost more than 0.7bar is a restriction problem of the exhaust because if it was it would produce more backpressure thus knocks (from what i know) , but in my case pfc doesnt show anything special regarding knock. Around 20 max which is the same as before. Ive been thinking about the blowoff valve too that could be causing the problem but dont know yet.

ive check for vaccum leaks and found nothing + i dont hear any whistle + doesnt have any lag, its comes on boost like it should

Im out of ideas and im really tired of this because im continuesly having problems with the car. Any help appreciated.

Thanks in advance

teamsprock

Check for boost leaks, how old is the wastegate? Where is the vacuum/boost source for the wastegate side port coming from? Is the boost gauge a quality/ known working gauge? How and where is it connected. Did you install the fire ring when installing the wastegate? To get lower boost than the spring you either are loosing boost somewhere (leak or huge pressure drop across the intercooler) or have an exhaust leak not allowing the turbo to get to boost. You can also test the wastegate with an air compressor and make sure it opens at 1 bar. Report back and we can go from there. This shouldn't be something too hard to figure out.

Also what intake setup do you have? Its not the stock piece is it?

Kevin01

Hello,

The wastegate is brand new as well as other parts. Its tial 38mm wastegate and yes the ring is installed. The side port of the wastegate is connected to a tee-piece which is connected to the pipe that connects the turbo with the intercooler (blowoff valve is on the same pipe). Im reading boost from 3 locations, 1 not that good quality (old one) boost gauge, boost controller , powerfc. From what i can see, boost controller and powerfc have 0.2bar difference. Ive checked for exhaust leak and there is none.

Regarding the intake no its not the stock one. Its a high mount setup btw.

Thanks in advance