Hi i have a 1990 rs camaro and i want to put a procharger on it and i need to know how much psi can i run with out blowing my motor. i built the motor my self it has a steel crank with stock rods and hypereutectic pistons (flat tops) about 9:1 compression right now. fully roller motor and bored .30 over. so how much psi can i run?

 

If the pistons were forged, I'd say 14 - 15 psi, but since they're hypereutectic, I'd keep it down to 11 - 12 psi.

 

I've been trying to come up with this answer myself. I recently acquired a ZZ3 engine (hypereutectic pistons) that I'm going to be replacing my tired 5.7 block with. Since I'm not planning on making insane power with this car (about 500 rwhp) and I plan to drive it a lot, hyper pistons are very appealing. The issue is they don't like detonation or excessive heat, and with my previous ZZ3 I quickly found out how sensitive the ring lands are to detonation with boost (7 psi).

Of course people are running plenty of boost on stock LS1 hyper pistons... so I'm curious to see who else is successfully running boost with hyperuetectics!

 

well i found a procharger with a 5 psi pulley on it so would that be ok. i mean this is my daily driver and i want it to last for a while

 

As long as you don't detonate I can't see 5-7 psi being a problem at all (or 10 psi for that matter). Among those running stock piston LS engines, I've read of people daily driving 12 psi and others running 16+ psi. Failure mode will likely be ring lands. For that matter I've been running 12.5 psi for some time and more recently 16 psi on stock cast L98 pistons, although they are a bit more tolerant than hypereutectic. I'm not sure what the heat limitations are on hyper vs cast, but you will have to consider ring gap because of increased heat expansion if you start getting brave with the amount of boost. In my case, my engine has almost 150k miles so my ring gaps are probably well past blower engine specs :-)

Just keep an eye out for blow-by and you'll know it's detonated a few times too many!

 

alright thanks for the info. i will be careful

 

It kind of depends on your tuning, keep it on the rich side and timing little lower and should last long time. Doesn't hurt to start small and work your way up and the 5psi pulley sounds like a good plan also.