Found my culprit for my detonation, melted pistons, blown head gasket

[GSTurbo1]

Well i did some research trying to find out why my car had overheating issues... turns out the spark ignition curve was way too aggresive under boost. Probably why my dyno numbers are so high, but ran too hot under boost, I bumped it way down while in boost until I get water/meth injection.

 

[xtotek]

That sucks as I know what you're talking about. I had a 92 TSI AWD that melted a piston and popped the head gasket. It was a heap that I was toying with but didn't get very far because the previous owner was an idiot who did zero maintenance.

 

[GSTurbo1]

Yea the original builder did a great job of building it, put a lot of money, time, and effort in but people after him had no clue how to maintain it. Need less to say I have learned a great amount of info on imports and basic engine design and am proud to call myself an amateur mechanic. Needless to say I will compression check and leakdown test before I buy another car.

 

[Josh97eclipse]

I bet that the piston was already melted when you bought it from previous owner neglect and not knowing what they had

 

[GSTurbo1]

That's what i'm thinking, or at least to make myself feel better . I really only drove the car for a month before the blowby got so bad I decided to rebuild. We compression checked as soon as I got it and the results were 150 +/- 10psi. So they probably were bad when I go it.

 

[BrokenTsi]

so how aggressive was the timing? and how did you find that out?

 

[GSTurbo1]

I have the map... but I did some research and it was the stock map that megasquirt supplied for the 420a which has been reviewed to be way too aggressive plus the timing advance does not begin to drop until it was hitting like 200kpa which my cars map does not even go that high. Tops I hit like 130ish.

can I post it on here?