you need a new head gasket and probably wouldn't be a bad idea to o-ring the block. Maybe coat your pistons.

 

Was he talking about the Lancer or the Evo? Our con rods are longer and more narrow and our pistons are known to have especially narrow ring lands. Now I can believe to an extent that the pistons aren't as much of a problem as the con rods (esp in high revs) if you can accomodate the engine with enough fuel, however I'm entirely too cautious to introduce that much boost on the stock internals...and once my FMU is installed I believe I'll have the highest flowing fuel system of any Lancer on these forums. You can reduce knock by adding more fuel tot he mix or run higher octane, but are you really willing to risk putting a hole in a piston or completely grenading?

 

I know of a Mazda running with stock pistons (and they aren't exactly great themselves) at 21 PSI... trying to blow the engine to see where the limits are... so far so good for them..

Detonation is what is going to cause the actual damage to the pistons.. running a 500 dollar knock protection system will eliminate detonation and prevent that kind of damage as well as give you the ability to run your engine and boost levels right to the ragged edge and as lean as possible for the most power.

But in the end the more factor of safety you have... (IE better internals) the better off you are!

Later.

Steve