forged pistons or stock

[240drfter]

is me buying pistons worth it.. how much more boost can my motor handle with forged piston upgrade. dont get me wrong i want them but im weighing my options. 700 for pistons or spend that on nistune and couple other goodies.....by the way(rb25det stock now, have 720cc injectors and he351...not on going to be) have burnt piston so i got to rebuild but just need to know how much power gain or how much safer it would be with or without pistons. want to run 20psi and if thats safe on stock might spend money on ecu stuff.....any suggestions would be appreciated

[Cjmartz2k]

Stock pistons will work, but at the power levels the Holset HE351 can make, if you are rebuilding anyways, I would throw forged pistons and rods in it. The big price is in assembly, not parts.

Are you going to use the variable geometry exhaust housing?

[240drfter]

yeah im working on figuring out an electronic controller but if its not ready i was going to eith make a manual threaded control rod or opposite apposing wastegates..but anyway...my problem is money i got all the gaskets and stuff but if i dont buy pistons i can get my head p&p and valve job. what is the limit on boost (good tune) stock pistons vs forged

[Cjmartz2k]

Boost has zero to do with with it. Cylinder pressure, horsepower, and tune are what determine when your motor is going to s*** the bed.

Anybody who says a RB20/25/26 can handle "x" amount of boost with stock pistons or forged pistons or whatever is an idiot and you should never listen to them again.

[Mistaken]

Dont cheap out on building the car, if it takes a little longer to spend the extra money and do it right the first time, then just wait.

Cjmart hit the nail on the head, the amount of boost means nothing. 20 psi out of a gt2871r (kind of small turbo) and 20 psi out of a gt45r (very large turbo) are whole different animals, either will easily pop the motor without a good tune and a well built motor.

[maryjane]

agreed with the above post, larger turbo at the same boost level is a totally different flow chart

[240drfter]

thanks for the input but i wasn't talking about different turbos i was talking bout the he351vgt inparticular. just wondering if i should bother replacing internals because the stock long block(from what i've read on nico) is suppose to be good to 500hp on good tune........i think that my money will be better spent on nistune and a dyno tune cause from what ive researched i shouldn't have any major problems making 400 or so safely with that setup........what do yall think

[Cjmartz2k]

Spend the money on getting your setup up right. If it's not got enough fuel or a bad tune, a built motor is going to turd itself anyways. Make the power on the stock stuff, wear it the f*ck out, and rebuild with forged stuff when it goes. Show me a pic of a bent/broken rod or a cracked piston with no knock marks, and I'll show you somebody who needs a forged motor. Melt the motor due to knock or a spun bearing or a melted piston due to lack of fuel, and I'll show you somebody who's going to do the same thing to a built motor.

[Darius]

Spend the money on getting your setup up right. If it's not got enough fuel or a bad tune, a built motor is going to turd itself anyways. Make the power on the stock stuff, wear it the f*ck out, and rebuild with forged stuff when it goes. Show me a pic of a bent/broken rod or a cracked piston with no knock marks, and I'll show you somebody who needs a forged motor. Melt the motor due to knock or a spun bearing or a melted piston due to lack of fuel, and I'll show you somebody who's going to do the same thing to a built motor.

This should be copied and pasted in the FAQ thread as the answer to the "How much power can my RB25 make on stock internals?" question.