Im building an ls vtec right now. My setup is a b18a1 block with stock pistons, gsr water pump, arp rod bolts, gsr oil pump, and brand new gsr head. What kind of horsepower am i looking at with the stock ls pistons? Should i get some different pistons, or are these fine? I plan on boost, and some people told me that gsr pistons would be too high of compression, that i would get more horsepower out of just boosting with the stock ls rods. What do you guys think? Thanks

 

run gsr pistons or get cam gear and notch the vavle reliefs of your LS pistons

 

What is notching the valve reliefs?

 

disregard that.. use the stock LS pistons for boost, or aftermarket pistons of the same compression ratio.. you want lower compression for boost than for NA.. GSR pistons would be fantastic, if you were going all motor

"notching the valve reliefs".. if you ever look at a piston, you will see dimples in it to make room for the valves, as this is an "interference motor".. that is why, when you break a timing belt, you bend valves, because they smack the pistons.. notching these areas on the pistons will make more clearance for your valves, if you start advancing the cam timing, as it will make the valves come closer to the pistons at full extension..