lets say i'm at 10-11psi on stock turbo/intercooler with my mods and i upgrade to a nice 20x10x2 frontmount intercooler... i'm tyring to justify making an FMIC my next mod and spending the money for the IC and pipes.

what kind of gains should i expect to see?

 

A drop in PSI will occur.

 

ok, so it drops and i raise it back up to 11 with my boost controller. gains?

 

If you stuff up the pipe selection or install them badly, or use a too restrictive core, you'll lose boost. Do it right and you won't.

There are two areas you make instant gains in. Lower pressure drop though bigger pipes and core flow area, and lower intake temps because of greater cooling airflow and bigger exposed core area. Greatly reduced heat soak also means no drop in power just from sitting at the lights.

Depending on your mods and FMIC installation, a 20-40hp gain is not unreasonable. There are many variables though.

Lower intake temps also mean better throttle response and (importantly) greater resistance to detonation. That allows you to safely run more boost (assuming you have the necessary fuel), leaner mixtures, more advanced ignition timing, or a bit of all three. All of these will give you even more power, although that sort of tuning is best done on the dyno.

You've been dominated!