General Motors developed the new L94/L99 engines, which utilize Variable Valve Timing (VVT). This technology is regulated by the use of cam phasers, which are computer controlled cam gears that optimize camshaft timing based on current engine rpm. Engine oil is pressure fed to the cam phasers through a series of passageways in the cylinder heads and cam while the engine computers control solenoids that adjust this oil flow into and out of the phaser’s control chambers. While this technology provides benefits such as fuel efficiency, it does present some limitations when it comes to performance camshafts. With such a wide range of valve timing movement, there is very little piston to valve clearance, which limits you to small cam profiles with little overlap.
COMP Cams® has addressed this concern of street performance and racing enthusiasts by developing the U.S. Patented GM L94/L99 Cam Phaser Limiter Kit. This valve train modification restricts the range of cam timing movement from 52° to 22°, providing the necessary valve clearance for more aggressive hydraulic roller camshafts with tighter lobe separations, all while still reaping the benefits of GM VVT technology.
This modification was designed and tested with the COMP Cams® XFI™ SPR Cams and #26918 Beehive™ Valve Springs. The results of this valve train combination are some of the biggest gains in power and torque COMP® has ever seen. Best of all, these significant increases in the upper-rpm range do not sacrifice any bottom-end or mid-range performance!
This revolutionary performance modification includes the phaser limiter and all of the accessories needed for installation into the GM L94/L99 cam phaser.