Ok so I'm getting aftermarket pistons and rods next week, and I need to figure out which would give me the most for my setup. I'm looking at getting CP Pistons and Eagle H Beam rods, and I'm not sure if I should get 9:1 comp pistons or the 10.5:1 ones.

My setup is as follows, and my goals are at least 400whp because I know my turbo maxes out close to 450 and I'm not upgrading the turbo.

- B18 block freshly bored to 81.5mm, honed and decked + CP pistons and Eagle rods mentioned above
- B16 head with ITR valvetrain, Skunk2 Tuner 1 cams, Skunk2 cam gears, freshly resurfaced, w/ a port and polish and valve job
- Victor-X manifold, 68mm throttle body
- Garrett T3/TO4E 50 trim stage III .63 A/R turbo
- 3" full exhaust
- 1000cc injectors + Walbro pump

I know I'll be pushing a lot of PSI to hit my HP goal, probably in the high teens or low 20s, so will the higher compression pistons make it so I don't need to push that much psi through? Or since my motor is built with the aftermarket forged internals I shouldn't worry that much about the amount of psi.

Thanks guys.

 

Im not as experienced as most of the guys on here but I do know that you don't want your turbo constantly working close to it's max capacity. It will just put alot more wear on it faster. I would either make your goals a bit more modest or think about slightly upgrading the turbo even though I know you stated that you do not want to.

 

Only reason I don't want to is because its brand new. I've heard I can hit 400whp reliably and it be safe on that turbo, but the max power that turbo puts out is 450, so if I'm in the 400whp range I'm happy. I'm asking about the compression to see if the higher compression will be able to let me boost less on my turbo hence extending its life even more.

 

10.5:1 compression at 400whp on pump is pushing it. If you can do something in the 9.5-9.7:1 range. Wiesco makes pistons that would put you around 9.3-9.8...when you say b18 bottom end what crank are you using? LS or GSR?

 

10:1

 

LS crank, LS block, it's an LSV setup. With stock compression PR4 pistons, with the B16 head I'd be at 9.7:1 compression versus the 9.2:1 stock compression. So I figure whatever pistons I'll get it'll end up another 0.5 on top.

So then I'll need to change piston brand as CP only has 9:1 and 10.5:1 for the bore I have. SRP has 9.7:1 for LS with VTEC head and Wiseco has 9.3:1 to 9.8:1 like you mentioned. They're both pretty much the same quality piston, right? I was going with CP for the better quality piston.

 

wiesco makes a great piston. jeff @ import builders did an article on most of the major piston manufacturers and found wiesco to be the best made piston out of all of them.

 

Great, thanks for the help guys.