whats a good general intercooler size for a rf320 running around 12 psi?

 

The dimensions depend on how much space you have in your car, and what kind of performance you want. Generally, larger intercoolers have better thermal efficiency and less pressure drop, but more lag. Also, if your car has an AFM, the larger the intercooler the slower the throttle response. Intercooler cores with a length/width that is more square tend to work better than those that are more rectangular. For a street car, keep the thickness to 3.5" or less, and a 2 to 2.5" pipe should work well in your case.

 

thanks Evil!