Originally Posted by MastMotorsports

Since its release, the benefits of GM Gen IV Variable Valve Timing (VVT) technology have been unknown to the performance aftermarket. Mast Motorsports recently conducted testing during the development of our L92 turnkey crate engine package to determine the performance gains of the GM Gen IV cam phasing capabilities. We would like to share these results publicly as we develop this technology for aftermarket applications. The test engine was a stock L92 with a L76 intake manifold package, 90mm drive-by-wire throttle body, 1-3/4 inch primary long tube headers, and 87 octane fuel on our SuperFlow SF-902 NSCR engineering grade dyno. The same stock camshaft was used in all tests shown below. The tests shown below were all performed with the same calibration; therefore, the tests with a stationary cam were slightly rich in places due to the inherent lower VE of no variable valve timing. However, the differences in the engine performance are still valid for illustrating the drastic gains that can be made using VVT.



The data in the graphs below compares the performance of the camshaft in a stationary position to the performance of our crate engine package calibration which phases the camshaft throughout the RPM range. The first graph shows the performance of the camshaft phased at -5 degrees (the camshaft position to produce peak torque on our calibration). This data is laid over our power curve and highlights the gains made in the upper RPM range due to VVT.



The second graph shows the performance of the camshaft phased at -18 degrees (the camshaft position to produce peak power on our calibration). This data is laid over our power curve and highlights the gains made in the lower RPM range due to VVT.



Since the GM Gen IV engines have been released, the relevance of VVT on LS series performance applications has been unknown. As you can see, the data speaks for itself. Phasing the camshaft produces more area under the power curve throughout the entire RPM range compared to a camshaft with a stationary installed center line. We are going to continue to conducting testing while finishing the development of our Phaser Series camshafts which are designed around VVT technology. In the coming weeks we will be developing our LSX block based VVT 454X engine. We are expecting some very solid numbers with these cams and VVT and are excited about bringing this technology to the aftermarket with our crate engine packages using our M-90 ECM.



Shaun

Mast Motorsports

www.mastmotorsports.com