I am deciding which compression I should go with. Some people say 9:5:1 or 9:1. Which one would be better for boost which would keep me running pump gas. I want at least 350-375whp. Also which would be better to tune. This is going to be a ls turbo setup . Still thinking of getting that vtec head also. I have a t3/t4 turbo 50 trim 60 ar just for the records


Modified by redturbocivic at 8:18 AM 2/11/2004

 

bump

 

any time you lower the compression it will be more street reliable under the comsumption of pump gas. 9.5:1 is still a good compression, but 9:1 is lower and would have to run more psi to make the same power. you could find alot of info. through a "search". i've read many arguements on compression on this forum. Basically 9:1 is turbo friendly, used with pump gas, on a daily ,street driven car.

 

run 9.5:1.
Its nice to run 9.0:1 you can run mad boost, but throttle response suxs.
What kinda Fuel Mangment are you running?
If your running a hondata or AEM EMS run the 9.5:1 and just get it tuned.

 

i have hondata s200. I dont want to run like 20-25 psi just to get my goal. If i do turn it up to that high i want moooore power.

 

9:1 for a pumpgas motor...

I wanna try 8.5:1 ona Pumpgas motor one of these days...I think it would be worth it.

 

i agree on 9:1 for pump gas. you generally have more room to play with. i don't know about the throttle response though. but i do know that people make great power with 9:1, 9.5:1, and even 10:1 with proper tunning. it's just i have to drive my car every day so i want to be 100% safe and still be able to turn up the boost and put down some serious numbers.

 

yea, this will be my daily driver. I want more room to improve with.

 

well according to alot of research i did, basically the lower compression ratio will produce slightly less power, but leave more room for tuning and streetability...i just finished my rebuild and now have my CP OS 9:1's in there with OUT boost so far, and to tell u the truth, it doesnt feel all that different compared to the ITR JDM's i had in there before. anyway i went the 9:1 route cause i wanted that extra tuning margin for error, also i wanted to increase the boost level to increase power instead of running the higher comp, and if im not mistaken the lower compression keeps cylinder temps slightly down and pressure on the walls lower. just my two cents.

 

Thanks, i think i am just going to go with them 9:1 cp's

 

I think CP measures their pistons @ 0 deck....so those 9:1s are really in the 8s if you dont deck the block.

 

I would go 10:1 and get it tuned well. Less lag and the same power with less boost.

 

yup suprdave that 8.5 would be worth while i know them sr20det are stock with 8.5 cr and they are 2.0 litres

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Suprdave &raquo;</TD></TR><TR><TD CLASS="quote">I think CP measures their pistons @ 0 deck....so those 9:1s are really in the 8s if you dont deck the block.</TD></TR></TABLE>

the block will be stepped deck