GSC Power Division billet S3 camshafts for the 08+ Subaru STi EJ257 with Dual AVCS. These camshafts are built to suit high horsepower cars with a power range of 750-1000 WHP and a rev range of 4500-9500 RPMs. Specific engine modifications are required to utilize the true potential of these camshafts including a built bottom-end (sleeved or closed deck reccomended), built/ported heads (castingmustbe clearanced for higher lift), GSC Power Division Billet S3 Camshaft and upgraded valve springs. A standalone ECU or tune with speed density is highly reccomended in order for proper idle characteristics.
Check Pictures for cam placement. Long nose = Left Side, short nose = Right Side
Due to the lobe size head castings will need to be machined down for clearance - Please check during install
Proper break in and running high zinc oil is a must on flat tappet engines
Must be installed by an experienced technician
Check AVCS advance during install - must be done by experienced engine builder
