Problem:

Loss of boost during a (typical) hard run through the gears. Motor runs fine (idle, throttle response), but while close to, or at full boost, all of a sudden the motor went 'flat'. Running 3mm head gasket, so power output is dog slow. BOV functioning properly. WOT at 6K rpms my manifold pressure is approx -1" Hg; no matter what I do, can never get it higher. Exhaust very quiet when running WOT, but not sure how much of that is due to change from OEM header to log style manifold (HKS Hi-Power exhaust).

Thoroughly checked and re-tightened all connections in the boost path, and all were OK. Checked for burn-through of rubber hose connecting turbo to hard pipe in pressure path, and looked fine. Only thing I can think of are (1) partially or fully open wastegate or (2) something amiss with the turbo.

In the past, when shutting down engine, if I listened closely I could hear the turbo as it slowly came to a complete stop. Can no longer hear that, but my testing has been limited to 'no load' conditions where I am underhood and blipping the throttle between 4k and 6k; even though the BOV would close and open during throttle blipping, does that necessarily mean the turbo should be spinning at all?

As I said before, motor runs fine, just very low in power - assuming that is due to the lower 9:1 CR with the 3mm head gasket. No unspent fuel or smoke of any type exiting the pipes during driving. Coolant temp normal. Vacuum line to boost controller fine. I bypassed boost controller and went straight to wastegate for a stab; took the car out for a very quick spin, and nothing different.

 

Give John a call. I'm sure he'd want to hear about this!

 

Already done, yesterday.............. They believed that I had probably blown a hose off in the pressure path, most likely down near the inlet to the intercooler. I updated them (via e-mail) with my findings this morning, so waiting for next step.

 

i sent you another email!!

 

by any chance, when this is happening, are you hearing a humming sound???

 

Nope - heard nothing.

Turbo is toast after only 3 months and 1000 miles. Visible scoring observed along approximately 1/4 the circumference on the output side. Was able to unfreeze, but only for about 1/4 turn, then it bound up again.

InlinePro seems to be stepping up to the plate, offering to replace for free. I'd certainly like to know the root cause of this premature failure.

Will update in a couple weeks once back on the road again. Could be worse - could be the middle of the driving/track season.

 

Naturally, I'd also like to know the cause.

I can't point it out enough how awesome InlinePRO is with their customer service and I have no doubt in my mind that they will support you through this whole thing. Two from this guy.

 

yeah i was going to say frozen turbo...but looks like ya already found it!!

 

How often do you guys here of GTxxR series prematurely failing? What's been the cause?

 

The only thing I can think of the is that the turbos are hybrids: Garrett cores with Precision housings. Maybe there was a mismatch? Manufacturing tolerances/defects? Could be a lot of things.