This cam has outperformed any cam we have tested it against to date, from idle to 4,200 rpm. It is also the largest drop-in cam that we sell. It works well in a 4bt application for this reason. 4bt’s usually have issues spooling turbos due to their limited displacement. For best spooling, use the 188-220-109 LSA, keep your timing conservative and use a 17.5:1 -19.5:1 compression ratio. A mild port job and larger valves can also greatly increase spoolup.
Install intake on a 99 centerline, performance springs and pushrods are recommended. If you have had your head or block surfaced, you need to verify piston to valve clearance.
For it to be “drop in” on a 8v you will need no more than .018″ piston protrusion and at least .055″ valve face depth with a standard head gasket and a 99 intake centerline. On a 16v you will need no more than .018″ piston protrusion and at least .038″ valve face depth with a standard gasket. If you do not meet the minimum requirements for piston to valve clearance, don’t worry, you can still run an oversize headgasket or cut valve reliefs.