Originally Posted by Itsmeagain
IMO comp ratio affects how powerful it is off boost, but not hugely how soon the boost comes in, a bit, but not as much as other factors.
If you want big power n little lag then low comp n big boost with clever cam/head specs is a better bet i reckon. dont have to go hugely low anyhow if you wanting about 600bhp, Rod running 7.2:1 i think.
What fuel can u get cheap? If its high octane then you can get away with higher comp too.
Also beware of people claiming they running high comp when infact they bullshitting to sound good
Steve, I nearly agree with everthing you say here
BUT
I have been involved with many tuners that run HI comp Big power cars,
all makes including Fords and Jap and they do exist and are mostly
reliable in this form.
You are right that there are lots of bull shiters but thats life.
This is mainly due to "MODERN" piston crown profile design.
Cant quote many examples due to "secrecy" that I have promised to maintain.
Some examples ...
1) My car is 437 bhp and runs 7.8:1 CR.
2) A standard EVO is 9:1 and I THINK is good for 380 ish bhp without CR change.
3) One of the 600bhp engines I have been involved with has a CR in excess of 8:1
(EGT's on this are well within limits !)