What went wrong with 7.5 PSI? and will built motor

[MINO]

I got a second opinion on my motor problems and found the compresion numbers to be 100, 205, 215, 200. Leakdown 50%, 10%, 18%, 30%. Tests showed the problem was mostlikely in the bottom end. I was told they could hear the blow-by with their equipment.

Now, the car runs fine with a little surge/back off on occasion while warming up. There is no oil on my plugs and I can't see any cracks on the pistons(as seen through the spark plug hole).

When my Greddy kit was first installed there was an improperly connected vacuum line to the wastegate causing 10PSI and massive knock on the top end. Would that short burst be enough to cause damage? What would go first? Rings or pistons?

I just want to make sure this problem won't happen again after I rebuild my bottom end. What set-up would you folks recommend for a daily driven Turbo?

Any ideas as to what's broken? Thanks.

------------------
HAWAIIAN BUILT...BUT
...STUCK IN L.A.

[DefAcura]

I think that going to 10psi with lots of knock would be enough to mess the rings up. Those tend to go first from what I've seen. A local guy blew the rings on his GSR motor, then the rings on his LS/VTEC motor after a few months with a DRAG Gen II turbo.

Usually you have to be really running lean or really getting alot of detonation to eat through a piston, and it'd probably be more noticable than what you're describing. Although if you had some really intense detonation, it could have happened.

Let me guess, the 100psi and 50% leak down was on number 1? That cylinder always runs lean due to it being the last injector on the fuel rail.

[MINO]

Thanks, very good guess. Would an adjustable FPR and after market fuel-pump help remedy this problem? Everyone was telling me the FCU with my kit would take care of everything.

------------------
HAWAIIAN BUILT...BUT
...STUCK IN L.A.