The Super Easy Boost Mod. Did I Get It Wrong?

[zoomzoom]

OK so i ive removed the boost solenoid from the wastegate setup and my setup is now as follows

.............................................(T-connector)

(Post-intercooler pipe) ========+=========------->(wastegate)

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.................................................||

.................................................||

.................................................( ) <--Restrictor

.................................................||

.................................................||

.................................................||

.................................................||

.................................................\/

.................................(Pipe back to turbo inlet)

Ok so my understanding is that the wastegate spring opens at 5 psi. therefore with my setup the line with the restrictor should bypass some pressure, keeping the wastegate shut past 5 psi and creating more boost.

however the turbo is not going past 0.4 bar or around 5.8 psi. ive drilled the restrictor to over 2.6mm and its still not giving any more than 0.4 bar. i dont get that, the line should be bleeding off plenty of pressure by now. in fact id expect it to be over boosting, but its not giving me anymore. WTF?

can someone shed some light here? am i boost-tarded or missing something here?

Edited November 3, 2008 by zoomzoom

[KiwiRS4T]

OK so i ive removed the boost solenoid from the wastegate setup and my setup is now as follows

.............................................(T-connector)

(Post-intercooler pipe) ========+=========------->(wastegate)

.................................................||

.................................................||

.................................................||

.................................................( ) <--Restrictor

.................................................||

.................................................||

.................................................||

.................................................||

.................................................\/

.................................(Pipe back to turbo inlet)

Ok so my understanding is that the wastegate spring opens at 5 psi. therefore with my setup the line with the restrictor should bypass some pressure, keeping the wastegate shut past 5 psi and creating more boost.

however the turbo is not going past 0.4 bar or around 5.8 psi. ive drilled the restrictor to over 2.6mm and its still not giving any more than 0.4 bar. i dont get that, the line should be bleeding off plenty of pressure by now. in fact id expect it to be over boosting, but its not giving me anymore. WTF?

can someone shed some light here? am i boost-tarded or missing something here?

Your diagram is correct so if you have connected from the intercooler pipe to the actuator with a bleed going back to the bov return pipe then I would expect better than 0.4 bar. Is this true all the way to 7000rpm? i.e. does it not increase with high revs? You could try a simple experiment - pull the hose off the actuator and try it carefully at first and then with more and more and see if your boost goes up. If it doesn't then you have to find out why - turbo no good, intercooler leaking, hoses leaking wastegate stuck open? If the boost does go up with the actuator disconnected then maybe the actuator (spring) is stuffed.

[zoomzoom]

ok i had a good chance to test it today. i took the bypass restrictor off, so it should have been keeping the wastegate closed the whole time, yet it would not boost past 0.5bar

i sure hope it wasnt a pressure leak in the intake because that would have spun the turbo very fast

so, where am i left now, how do i go about testing the turbo? shaft play?

[KiwiRS4T]

ok i had a good chance to test it today. i took the bypass restrictor off, so it should have been keeping the wastegate closed the whole time, yet it would not boost past 0.5bar

i sure hope it wasnt a pressure leak in the intake because that would have spun the turbo very fast

so, where am i left now, how do i go about testing the turbo? shaft play?

Did you try pulling the hose off the actuator (and perhaps plugging all the hoses)?

If you get stuff all boost then check for leaks and unless anyone has a better idea it may be turbo off time. Or see if the actuator is stuck.

[zoomzoom]

bad news im starting to think.

i havent noticed before but i found black oil dripping from the rubber coupling on the air intake just before the throttle body. its dripped onto the cam cover

excess oil in the intake? bad turbo seals? i not sure if the turbo is bad, ive never seen smoke on startup

[RBPOWA-(TJ)]

dont mean to alarm you, but i think there was a thread somewere recent with the same kinda oil leak, think it came down to turbo is near its due date :S

found that link http://www.skylinesaustralia.com/forums/Oi...er-t242873.html

[zoomzoom]

oh i was already alarmed, dont worry ive been reading those threads

i am curious about the GCG turbo upgrade over the stocker.

with some holidays coming up ill be able to check out the turbo