9.1
9.5
10.1
10.5

blower

 

I personally would go with either 10:1 or 10:5 CR.

You could possibly make more hp at lower boost. So MY theory is at 6lbs of boost you could make the same or more hp as someone who has 9:1 CR at 10lbs. I would run 10:5 and run good fuel.

 

what application? What fuel? What blower?

Whatever compression allows for the maximum amount of boost your blower is capable of with the fuel your running would be “optimum”.

 

im freshening up my 416 novi 2ooo...
had a choice of 9.7 or 10.2 wiseco
i went 9.7 pistons and the wider pic for tuning
engine was 9.5 w crappy mayle pistons

 

10.2:1 on c16

 

fuel choice, cam, combustion chamber, piston design all play into this so there is no simple answer, only pay yur money and takes yur chances

here is my 02

first decide on the fuel and cam,

I like 10-1 on pump gas, and 11-1 or so on e85 for a street machine

compression ratios on race gas can be similar to e85

I ran 9.5 to 1 on my twin turbo ttix car which allowed me to make 600 to the wheels on pump gas and 800 on meth

it's an ez combination that's held up well

 

I vote 9.5 on pump. its the perfect middle ground IMO

 

Which ever allows the ignition timing for best power/torque for your package and desired boost, fuel, charge temps etc etc without being knock limited.

Easy.