Iím kind of stumped here. Canít seem to make boost past 20-22 psi
with a new drop-in turbo. On the street, boost builds to roughly 2,600 rpm, then falls completely off. Weíre talking 22 psi
to 10 instantly, but at wide-open throttle.
Things Iíve done:
-Checked all intercooler plumbing, clamps, boots, replaced compressor outlet O-ring, pressure tested the turbo system to 45 psi
and no leaks whatsoever.
-Replaced OE turbo intake boot (the one that cracks and rots out)
-Checked shaft for side-to-side play = looks good
-Checked shaft for in-and-out play = looks good too
-Checked compressor wheel to see if it was hitting the housing = looks fine
-disconnected the EBV (unplugged)
-There are no exhaust leaks anywhere either
-fuel and oil look perfect (ICP
maintains at 2,900+ psi
-Tried a new MAP
sensor too (a code had been stored) = no change
Is something physically stopping the turbo from mechanically making more boost? I hear nothing. Why is it dropping off so suddenly at WOT
? Should I take a look at the turbine side? Keep in mind that the turbo is brand new. It has the 1.15 non-wastegated housing.
I know that the EBV is supposed to default to the open position when the harness is unplugged (correct?), but could it somehow be flapping back closed on pro-longed boost runs? I dunno. Iím having a shop take a look at the turbine side right now, but am lost on what this could be.
Any suggestions are much appreciated.
PS - Stage 1 injectors, Adrenaline, TW tuning