My guess would be a hotter intake charge if that was the case. You(I'm assuming) are using a MAP so it won't lean or richen the fuel like a MAF setup. However your turbo is working harder to maintain boost and going out of it's efficiency range.
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It wasn't, making good power per lb of boost. I think I was around ~27lbs for the 670whp #. If it was a leak that bad I wouldn't have made the power.


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Chamber temps go up with lean A/F. since you only melted 1 piston, lean in that bore. A vacuum leak is unmetered air, and lean.



That piston melted in about 3 seconds of WOT, from a vacuum leak.

 

Damn.... never thought vacuum leaks could be so dangerous

 

ive melted one piston myself (je piston) and have seen numerous other melted pistons, different manufacturers, all with a hole along the ringlands, all honda engine platforms. and to be honest, most were cyl #3. kinda seems as its a characteristic of honda engines?
our superstock escort with 16.7:1 compression melted a je piston and it was towards the top outter edge of the piston.

where was the above mentioned leak and what cyl was that from?

 

amen

 

Chamber temps go up with lean A/F. since you only melted 1 piston, lean in that bore. A vacuum leak is unmetered air, and lean.



That piston melted in about 3 seconds of WOT, from a vacuum leak.
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Not arguing, I would think with a leak and 25+ lbs of boost in the cylinder it would push sir out and be rich, that is what I was thinking ??

Besides, we don't a compression test and all cylinders were within +/- 2psi.


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Thats a characteristic of most 4 cylinders in general, cyl 3 is pancaked between 2 and 4. They normally run hotter.


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i always assumed it was due to the design of the intake manifold. why doesnt 2 run as hot as 3? sorry to clutter your thread, just kinda on that topic.

 

Think firing order.

 

aaahhh, i see. thank you for the clarification