Doing a 2.3 build from jasckson auto machine outta maryland and debating on either getting 8.5:1 or 9.1:1. I'm leaning towards the 9.1 but not 100% sure. Plan on running a fp black w maybe a 35 r in future. Any input would be great appreciated.

 

9.1:1 or even higher. Im doing 9.5:1 on my 2.4l

 

I'd do 9.1:1 at the least. If you're going to be running E85 I'd go 10-10.5:1 compression.

 

11:1 here on E85. I did some tuning with it on 93 and got 570whp on the VD at 26psi. Mods in my sig. Compression makes a huge difference in off boost power, i love it! Do at least 10:1 man.
Beware, some advertised "10:1" pistons are much higher than that. I have a BR shortblock that david said was 10:1, turns out its over 11:1 with an evo 8 HG. I'm using an evo 9 HG to lower it some. It has the newer style JE BR pistons. My advise, do the math yourself!! Just a heads up......

 

I have a jam 2.3l 8.5.1 on e85 fuel. Tony from JAM recommended it for my future setup with a fpblack. I'm now going with a fpred. David buschur had a thread that discussed the diff in cr's. A built motor with 8.5.1 will still make the same power as say a 9.5.1 cr but will just need to run higher boost to get to it. Yes alot of guys are going with a 10.5.1 cr and 8.5.1 is an old school way of thinking especially with the e85 craze. Jst my thoughts
Cheers

 

Anyone have link to David b cr thread

 

I went 9:1 on my 2.3 build.

 

No link to that thread, but BR's 2.3L motors are 10:1 (both standard and high rpm 2.3)

 

i say 9:1 for sure higher.

 

i have 9:1 and off boost throttle response is better then my dads 99 c5 vette lol.. so i dont think you'll have a problem going with this CR or higher etc.. he doesnt understand how a small 2.3L has more response then his 5.7L v8

 

JEEZ! Read right over what i said. ^^^^ This is NOT true!

 

how do you know what compression it is? i always thought you went by the compression test psi numbers?

i never seen past 155 yet on mine.. and cams play a roll in the compression test results as well.

so if i have 9:1 je pistons and im testing 155 with kelford 272's wheres that put me?

also keep in mind the engine only has 280 miles on it, so im sure it will seal even better since im running brad penn which is a partial synthetic which does not halt the ring sealing process.

 

http://www.rbracing-rsr.com/compstaticcalc.html

formula for CR calculation

 

Two types of compression ratios as well, static and dynamic. Camshaft duration and timing will affect the dynamic quite a bit.

 

+1, perfect for any boost level