the norm for most motors now adays is 10:1 for a 500+whp motor that sees the track.

for daily drivers, i would run 9.5:1 because youll mostly be on pump gas, and regardless of what you do, you can get a bad batch of gasoline.

Im a fan of 10:1+ turbo motors, small turbo, big power.

Higher compression will spool the turbo faster, volumetric efficiency increases, the motor is much happier.

Think about it in NA terms as well. Stupid high compression (12.5:1+) for a pump gas motor on the street sucks. you will have to pull so much timing to avoid detonataion that it makes the motor lazy. things arent as crisp, combustion isnt as ideal, etc.

Same way with a Turbo motor with really low compression. Sure its better on pump gas an safer, but youll have to run MORE BOOST to make the same power as a higher compression motor.

So in short, 9.5-9.8 is good for a STREET motor IMO. If your building a semi track/race/street combo, then 10:1-10.5:1 is good.

problem is i dont think most people on this board can pull off high compression turbo motors because they wont spend the money to do it right.