Volkswagen Corrado Forum : “1991 vw corrado g60”

You could get a K&N air filter/cold air intake to add a few HP economically.  Another option would be to try to add headers, if available, to increase exhaust output.  If your state does not have emissions laws, you could remove or hollow out the catalytic convertor and add larger exhaust tubes to the rear to increase flow as well (note:  may be a violation of Federal law).  Another possibility would be to port and polish the intake manifold.  Depends how much you want to spend.

bahnbrenner.com or kompressorkanada.com will have alot of stuff to build a g60 the skys the limit but the charger is the weak link on that car if you have the fincial power go check bbm lysoholm charger