Does higher compression ratio raise TQ off boost?

**JET** · 11-16-2012

A bit, not a huge difference though. It is a trade off, higher comp gives a little more torque and better spool, but you can't run as high of boost (compression ratio doesn't get to run through the intercooler).

**Murlo26** · 11-16-2012

Quote:

Originally Posted by JET

A bit, not a huge difference though. It is a trade off, higher comp gives a little more torque and better spool, but you can't run as high of boost (compression ratio doesn't get to run through the intercooler).

Depending on the fuel, higher compression doesn't matter if you have the fuel to back it up...e85/e98.

**JET** · 11-16-2012

Quote:

Originally Posted by Murlo26

Depending on the fuel, higher compression doesn't matter if you have the fuel to back it up...e85/e98.

That is not really correct, only if you have reached the limits of your turbo system. Here is a very simple static boost calculator to see the correlation between CR and boost. Just remember, boost gets to run through the intercooler after compression and CR does not.

http://www.rbracing-rsr.com/compression.htm