30psi on straight 93 octane pump gas??
is it just me or dont this sound like not safe?
here in so cal we only have 91 octane and the tuners don't even run that much boost when tuning for 100 octane.

 

Different tuners have different methodologies.

Some people prefer to run the timing aggressive and leave the boost on the safe side, some prefer to run boost and keep the timing safe. Both of these things have a direct correlation with cylinder pressure which directly determines torque output.

Some cars can run 30 psi easily on pump gas, on a stock turbo, on 91 octane I don't think you could run that with any amount of timing taken out of the car however. A 35R+ framed turbo, with a big intercooler, low compression pistons, etc etc is a totally different story.

Scorke

 

with supporting mods yes, 30 is a stretch but it depends on the turbo and the tune

 

You most likely have a good crank too. This is about the best you can hope for in a blown engine assuming your valve train is intact. Aluminum has such a low melting point compared to cast iron your block is probably fine.

 

Looks like classic signs of detonation, not going lean. Do you have pictures of the spark plug, cylinder head, and valves from that cylinder?

 

I'm now looking at the top of the cylinder wall. That is most definitely detonation. That motor was ran into the ground with knock.

 

That motor has most definitely been melted, not broken away.

That is a sure sign of excessive heat to me...

Scorke

 

x2, that was heat and the top of the cylinder wall looks beat to hell because of the piston melting/warping and beating the cylinder wall

the head shows no signs of detonation neither do the other pistons

 

As compared to detonation where it uses freezing power?

 

Listen, the boundary layer was disturbed from the detonation pulses allowing heat to get to the piston. Notice the pitting and eventual failure at the thinnest portion of the piston. To top it off, its on the intake side of the motor. Failures with this kind of pitting and material buildup on the cylinder wall on the intake side are indicative of detonation. A failure from going lean will cause the exhaust side of the piston to be destroyed.

 

With detonation the damage is done with pressure, with a lean condition it's done with heat.

If it was detonation you would see that the ring land had broken off, it seems very clear to me that this piston has melted becaue the edges are smooth and round, most likely because the piston went molten.

Scorke

 

wat?

Scorke

 

I've provided my input to help the OP and am through with this.

EDIT:
read : http://www.streetrodstuff.com/Articl...ne/Detonation/

 

tune problemsss... Doesn't matter how bullet proof your block is if you run lean or predetinate this is what happens.

 

Could it be that the particular injector clogged/failed causing it run lean and melt that particular piston. If he was tuned that rich and then all of a sudden go lean during a particular pull means, bad pump, injector, killer boost spike of at least 10psi than he's tuned for. Something along those lines.