I fitted a shtick to my corrado (obd1) and there is no surge at 4000 mate , does it pull all the way to the redline ? Or does it noticeably lose lots once over 4 grand You won't get a vetch like kick from a schrick manni all the power it develops is lower down at 1500 to 4000 rpm , I had my car on the rollers at stealth and it produced 196.1 bhp and 189 lb/ft , after the schrick and no remap it made 198.5 and 201.1 lb/ ft Schricks are about torque gains and there all focused on low down power , if something is stuck open I'd say you was more likely going to lose torque rather that horsepower ,