I would use an intercooler, even if you are only boosting 6 psi.
Any time you can reduce the intake air temp (especially compressed air from a turbo, it's hot!) do it!
There is no good reason why anyone would not choose to use a intercooler. IMO.
Do not listen to most turbocharger books stating is you are only running 6-8 psi of boost pressure, you do not need a intercooler.
What if you are running 10:1 compression ratio & only want to run 6 psi of boost pressure,,, do you think there would be more of a tendency for detonation? Intercooler, = less chance & simply makes a good reason to add a intercooler.
They are affordable, easy to install.
MBHD
