OK, we'll back into it from here. Since you can't afford forged pistons, and the compression ratio is high. Applying boost really raises the risk of detonation. Since we are dealing with hypereutectic pistons, detonation is your biggest enemy. The factory hypereutectic pistons are very hard, and are therefore brittle. They have proven time and time again to be unforgiving when subjected to detonation. Addtitionally, your N/A motor lacks the oil sprayers found in the 7M-GTE and 2JZ-GTE. These sprayers spray oil on the bottom of the pistons, providing additonal cooling which helps reduce the chance of detonation.
I'd say you probably can't safely run more than 3 or 4 psi of boost on those factory pistons if reliability is your primary goal. Anything past that and you are really flirting with danger. You COULD run more, and many people do, but you are pushing it.
However I would like to point out that if the cost of forged pistons is out of the question, you probably shouldn't be messing with modifiying a car. Modified engines break, that's a simple fact. The less time and experience the owner/builder/tuner has, the more likely it is that an engine failure will occur.
I guess what I'm getting at is if the few hundred dollars for forged pistions is too much, the considerably higher cost of a broken motor will be as well.
I'm not trying to discourage you. I'm simply making a statement that should be made a lot more frequently in this business/hobby. Speed is
not cheap. Anyone who says any differently is selling something.
No, but that would be a REALLY lame car. A 3500 + lb car with an 8.5:1 3.0 liter N/A would be a real pig to drive. I'm talking mid 80's Volvo kind of pig...
