Rb20det Boost Cut?

[dougs]

hey guys i just changed the inlet and outlet gaskets on the turbo as it was making no boost when i bought it, and now that the exhaust leak is gone it sounds normal and makes boost, but cuts out when it hits around 12-14psi. the car is completely stock, and i mean literally completely stock. first off, how come it makes 14psi. And secondly, is there a built in fuel cut etc that kicks in around 1bar? need to get it on the road asap as my other cars have a few issues lol. thanks in advance guys.

[mad082]

yes there is a built in cut in the ecu.

as for the pressure it is running, check to make sure there is no boost controller in the hose from the intercooler piping to the wastegate actuator. if there isn't then when you replaced the gaskets you may have reinstalled things so that the wastegate flap is fouling on something and not working properly.

[dougs]

gonna pull it all off again tomorrow morning and check it out. thanks for the reply

[blind_elk]

Pretty certain RB20DET doesn't have a fuel cut. Only limiters built into the R32 GTSt is a rev limiter (around 7500), and a speed limiter (180kph).

So, how many revs are you pulling when you have 12psi and the "limiter" cuts in?

It could be running high boost for a number of reasons, like a leak in the wastegate actuator hose, or the wastegate isn't opening correctly.

[dougs]

the wastegate vacuum hose has a manual valve t'd into it, so i removed it today and it now hits around 12psi again but the engine doesn't cut out. it still acts a little strange sometimes when its on 12psi i.e hesitation etc. but overall seems to be running better. and no fun police now lol. looks like its making 12psi at around 3000-3500. couldn't really watch but it build really quickly.