I am building an engine at the minute and am debating wether or not to go low compression. I am only wanting to run about 15psi of boost and would like the car pull more at the bottom end rather than the top. Should I leave it standard with regards to the compression ratio. It will be running a stage 2 turbo as thats what I've got and just had it rebuilt but want as little lag as possible. I have been looking around and it seems the higher the compression the more torque you get but obviously I can't go too far due to detonation etc.

 

all depends on what power you eventually want to run if your goner be happy with 15psi then leave the compression ratio aloan.

 

Running 15psi i would keep it std comp

 

low compression will be shit at the bottom end.

evos run around 9:1 and lots of boost as standard
and im running 20psi on standard bottom end

 

mine is low comp and i only run 14psi. i got 236lbs/ft torque which equals loads of bottom end grunt

 

Thanks for the replies guys. Gonna keep it standard comp.

 

whats the most boost you can run on a standard setup. i was told that it was 18psi

 

~22psi without any trouble and upto ~29psi with careful setup.

 

I bet at 29psi it would pull your arms off. I couldn't imagine running an RS at that sort of boost.

 

fookin hell.

my mate had an RS Turbo and he was trying to blow up his 1.6CVH as an excuse to upgrade to ZVH power and he ran it at 27psi for 2 weeks before it died. That was without adjusting the fuelling too!

i would imagine that after 18psi your gonna need a fith injector of some sort?

 

but how long will it last before it kinda cries for help?

 

i think its performance Ford that have an RST running stupidly high boost on standard engine and thats seems to be lasting

 

1bar? Evo's don't have a CVH either so it's a bit pointless comparing the engines.