i got a 1990 crx with a T25 turbo with and intercooler installed but whats the best way to tune it

 

We need more info than that.
Did you put it together yourself?
what motor?
what ECU?
what injectors?
what fuel management if any?
any other engine mods?

I would just take it to a competent tuner in your area with a dyno.

 

That depends on how much your willing to spend and what are you lookin for in performance. you can get AEM ems but thats most likely overkill for you or you could just get something simple like a chip tuned with Crome. Also converting to obd-1 would help too.