WARPNOVA

iTrader: (3)

I am still trying to decide what my compression ratio should be. I am going ahead and having ERL build me a 427 6bolt superdeck1 out of my stock ls1. I am trying to choose the right piston and am worried that 9.6 to 1 compression ratio will be too high for me.

I have three piston choices to pick from and they are all Wiseco pistons but the compression height is different on all three. My goal is to reach 800 or more rwhp on 91 pump gas with as little boost possible from my APS standard kit with LG Motorsports upgraded Turbos. I think I can reach this goal but don't know what the best compression ratio is. I thought I use to know and was aiming for 9 to 1 but given the added cubes and the turbos feeding this large of motor I am thinking the higher compression ratio will help but how much higher.

Keeping in mind this is a %90 street car and will be driven at the track once and a while.

The dished pistons I have to choose from without going custom which I would like to avoid are -32cc with a comp height of 1.115 , -23cc with a comp height of 1.140 , and -20cc with a comp height of 1.110

I am worried about my quench area as well so the -32cc kind of scares me, that and I would have to mill the TFS 235 70cc heads down to get the compression ratio back up to at least an even 9 to 1. I didn't really want to mill the heads as I am worried about thinning their deck too much as I don't want to be lifting heads or blowing head gaskets.

Any help or input would be greatly appreciated, I have asked some other people but I am still waiting to hear from them once they have time.

robert miller

Will be pushing it up I am 9:8:1 on a ls2 with 402 ci. I have TF 225 heads a good cam and some other stuff. It is making 857 rwhp on a mustang dyno. behind a a4 trans and that is with just under 16 psi. Hope this will help you. But the cars has no problems at all running like hell. I have a A/A PROCHGER YSI unit on it and it will just not stop pulling on the top end. I am sure turbo will do the same.....

WARPNOVA

iTrader: (3)

Thanks bud I appreciate your input and I have decided to use the -23 even though they have the biggest piston compression height. Should get me to about 9.5 to 1 I hope depending on how much the piston is in the hole.

Dam just 16 psi and 857 rwhp, that is what I am looking for right there and those numbers are off of a mustang dyno to so dam. I can't wait to get mine all done now but I will have to wait till the end of the year before I can get mine all finished up. Oh well patience is a virtue right. lol

Thanks again robert miller.