pettyboy69

Ok so last night my tuner and I went to mess with my 02 turbo s2k. The car has been turbo'd for some time now and has always been 110% reliable with 0 issues. I dd the car at 6lbs on a holeset hx35, twin gates, sidewinder, id1000s ect.
There is a race today that we were trying to make so I decided to up the boost to 12lbs and re tune. We did probably 15 second gear pulls and the car felt great, then a few 3rd pulls and still great but the first 4th pull it layed over pretty hard in the top which we thought was because af was mid 10s. Second pull it leaned out just a little and we logged high 10s but it layed over again in 4th and let go. Pistons are severely pitted and holes from detonation in one piston, and even the sleeve has a very deep hole in it? Car never has any issues until last night.

The only thing I can figure is I pushed the limit on pump gas. I figure between 450-500hp would be about the limit on pump but I don't think the car was making over 500 especially on the amount of boost we logged. Timing wasn't aggressive as we were pulling about 1 degree per pound if boost and the motor saw about 19-20 degrees tops, but maybe that's too aggressive for these motors?

Any help is appreciated as I said I'm pretty sure what happened but I just want to make sure.

wadzii

too much fuel and not enough timing makes the exhaust valves reallllly hot. this damage is from pre-ignition not detonation. When the motor felt like it was laying over that was pre-ignition, detonation wont usually cause the car to feel like its loosing power like that.

pettyboy69

But the valves are all still there and sealing just fine? All the pitting in the pistons seems like pretty clear detonation but I could be wrong?

KaNgArOo

No idea what happened, but you should have tried that on e85. Might have saved the motor.

indi00

20 degrees at 12psi? What octane gas? That seems a little high on pump.

s2konroids

For me timing has been too advanced, from what I've seen in the past the hole in the liner is typical.

1SlowSi

Pre-ignition will burn holes/melt your pistons. If there are Knicks in several places then chances are it was detonation but I assume you would have heard that? I blame the tuner and not your car.

pettyboy69

I would have to look at the map again and see what timing was at other places, fuel was 91 octane. I was also thinking it was possible a bad batch of fuel as well but like I said any help is appreciated.

I was running e85 for a while but there is only one pump within 200 miles of me and about 6 months ago they hiked the price up 1.50 over night and now it is well over 5 bucks a gallon because they have the market corned. I'm thinking about buying e98 in 55 gallon drums because that is a ridiculous price for e85 especially here because it is e65-e70 about 8-9 months out of the year because it's colder here in Idaho. T sucks because know the motor would be fine ifi had been running e85 but live and learn I suppose. I was only running 6lbs on the car on pump for the last few months and it's been great but once i turned it up to 12 it let go

ROFLv8

I ran 14lbs fine on pump gas but timing was at like 13 degrees

YuriArts

Didn't you listen for knocking? We always put a sensor on the engine and listen with headphones for knocking. Then you know when to adjust your timing.
I'd also say your tuner should have known that.