Using lighter rods and pistons for more hp?

[8600RPM]

If I were to replace my stock rods and pistons with much lighter ones, how much parasitic power loss would be frees up and translated to power at the wheels? Same stroke and dimensions as stock.

[pbonsalb]

Your wallet would be much lighter. Your power would not be much greater unless you built the head as well and increased the rpm.

[///M Power-Belgium]

Guys think first on our screwing bearings...

[dparm]

Originally Posted by 8600RPM

If I were to replace my stock rods and pistons with much lighter ones, how much parasitic power loss would be frees up and translated to power at the wheels? Same stroke and dimensions as stock.

I don't think you would make measurably more power, but the car would rev faster and feel more responsive. You are correct that it will basically "free up power" (rob less) but not generate more.

On a dyno, it's going to be within the margin of error. Subjectively, however, you might feel a difference between shifts at WOT.

[FogCityM3]

Isn't getting pistons without a re-boring not advisable due to potential loss of compression/blow by?

[carlitosway6891]

not enough to justify the cost of doing so. yea you would get some more throttle response but the real question, have you priced out cost on pistons and rods? and then consider labor.....hp to $$$ gain would definitely not be worth it, at least to most ppl

i believe this would only benifit you if you were going for some serious HP from some type of forced induction. my two cents

[Sneaky Pete]

As a side benefit, reducing the weight of the reciprocating parts reduces the load on the crank bearing oil films which would extend the life of the bearings.