GM Performance Parts LSX 454 - Is Everything Bigger In Texas?

In order to maintain valvetrain stability at high-lift, TSP upgraded the stock GM LS7 heads with its own chrome-moly pushrods and dual-spring kit, which includes premium-grade springs rated to 0.660-in lift, hardened seats, Viton seals, and titanium retainers. GM LS7 titanium intake valves (2.200-inch) and hollow-stem exhaust valves are retained (1.610-inch). Once everything is in place, the rocker arms are torqued. Texas Speed uses a stock GM LS7 intake, LS1 coil packs, FAST 50-lb/hr LS7 fuel injectors, a PTM 92mm throttle body, and an 85mm MAF. For the baseline configuration, a custom Comp Cams hydraulic roller with 254/260-degrees duration at 0.050 with 0.667/0.662 lift on a 115 LSA was utilized. After a series of low-rpm pulls to verify that the GM LS7 computer was operating properly, Jason Mangum locked the timing in at 28 degrees total utilizing HP Tuners VCM suite, and the motor was unleashed.

TSP substituted one of its own 100mm Mass Air Flow Sensors (PN 25-100MAF, Retail $249) and rescaled the LS7 computer for the difference in airflow. According to Jason Mangum, "The MAF has a billet main body, new GM sensor-adapter harness, and a 4-inch silicon coupler. It will work on any LS-series engine, once the MAF table is scaled accordingly. In our testing, the MAF will provide all of the airflow necessary to utilize the largest throttle bodies available, so as to not restrict airflow into the engine."

Corrected horsepower and torque went up from a baseline of 661.8 horsepower at 6,400 rpm with 591.7 lb-ft of torque at 5,200 to 679.8 horsepower at 6,800 rpm with 604.2 at 5,200 for torque. Gains of 18 horsepower and 12.5 lb-ft of torque resulted from the MAF swap. Power and torque increased all across the rpm range.