as a general rule of thumb...i know like the 4a and 1g use the superchargers, but superchargers are normally suited to high capacity engines more so than turbos...turbos spool up quicker depending on the size of the turbo and your engine...obiously using a t04 turbo on a near stock 4a is gonna get u fuck all mojo (if it doesnt blow your engine) until it is revving high enough and pushing enough air to get those big turbines moving...go a smallish turbocharger on your 4 cylinder man (look for something like a hitachi unit off a 200sx or nissan gtst...more efficient on smaller cap engines...leave the supercharging to the bigger guys...plus in a 4/ 6 cly the turbo is more exciting to drive!