Additional components included a pair of 45mm Hypergates and a single RacePort blow-off valve all from Turbo Smart. The exhaust system featured shorty truck headers from JBA connected to the turbos using short tubing sections designed to adapt the stock exhaust flanges to the T4 turbos. The Turbo Smart Hypergates were positioned inline on the adapter tubing, while the single RacePort blow off valve was welded to the single 3.5-inch aluminum inlet tube. CXRacing also supplied the necessary 3-inch aluminum tubing, couplers and clamps to connect the turbos to the intercooler as well as the 3-inch stainless tubing, v-band flanges and clamps used to complete the exhaust. In addition to offering complete kits, CXRacing was a one-stop source for our do-it-yourself turbo kit. The final upgrade was to replace the 36-psi injectors with a set flowing 75 lbs per hour. With Modern Mouse ready to rock, we first dialed in the air/fuel mixture at just seven psi before working our way up in power. Even at just over 7 psi, Modern Mouse produced nearly 750 hp. Eventually the boost was increased to nearly 13 psi (12.8 to be exact), where Modern Mouse pumped out 963 hp at 6,500 rpm and 868 lb-ft of torque at 5,000 rpm. Torque production exceeded 800 lb-ft from 4,650 rpm to 6,300 rpm, but never dipped below 700 lb-ft. Being so close to 1,000 hp, it took all of our will power to stop from cranking up the boost. In the end, we decided to limit the boost to a reasonable level. 10 All testing on the NA and turbo combinations was run with the FAST XFI/XIM management system. Fast also supplied the necessary 75-pound injectors for our turbo motor.10 All testing on the NA and turbo combinations was run with the FAST XFI/XIM management 11 We ran Modern Mouse normally aspirated prior to the installation of the twin turbo system. Obviously the heads from Procomp Electronics worked well, as the 383 responded with peak numbers of 539 hp and 516 lb-ft of torque.11 We ran Modern Mouse normally aspirated prior to the installation of the twin turbo sys 12 The custom turbo system utilized JBA shorty truck headers feeding custom tubes to adapt the stock header flange to the T4 turbo.12 The custom turbo system utilized JBA shorty truck headers feeding custom tubes to adap 13 CX Racing supplied a pair of 76-mm turbos. In truth, these were more than we needed for Modern Mouse (they also offer smaller 67-mm and 72-mm versions), but we had them on hand. Each of the T4-based, 76-mm turbos featured a 4-inch compressor inlet, a 2.5-inch discharge and 3-inch exhaust outlet. The exhaust system consisted of a pair of 90-degree, 3.0-inch stainless steel elbows.13 CX Racing supplied a pair of 76-mm turbos. In truth, these were more than we needed fo 14 To ensure proper boost control, TurboSmart supplied a pair of Hypergate45 waste gates. The trick threaded collar design not only decreased overall size to improve fitment, but facilitated easy spring swaps. The waste gates were secured to the dedicated waste gate flanges using V-band clamps.14 To ensure proper boost control, TurboSmart supplied a pair of Hypergate45 waste gates. 15 TurboSmart also supplied one of their RacePort blow off valves. A high-flow blow off valve is a necessity on high-boost/power applications. The blow off valve opened to provide pressure relief during shifts or lift-throttle applications. Without the valve, the pressure wave that flows back after slamming into the closed throttle body would try to escape back out the turbo. Attempting to instantaneously stop or reverse the flow of an impeller spinning upwards of 100,000 rpm is not a good situation! The RacePort shared the threaded collar design with the new Hypergates.15 TurboSmart also supplied one of their RacePort blow off valves. A high-flow blow off v 16 Keeping things cool was a dual-inlet, single outlet, air-to-water intercooler from CXRacing. Capable of supporting over 1,500 hp, the dual-core system was supplied dyno water for this testing. CXRacing also supplied the necessary 3.0 and 3.5-inch aluminum tubing, couplers and clamps to complete our custom kit.16 Keeping things cool was a dual-inlet, single outlet, air-to-water intercooler from CXR 17 With everything finally assembled, we were finally ready to run Modern Mouse under boost. We started at the lowest boost setting (7-psi waste gate springs) and worked our way up to just under 13 psi. Even at 7.3 psi, Modern Mouse pumped out nearly 750 hp, but things got really interesting once we cranked it up. Running 12.8 psi, the turbocharged 383 produced 963 hp and 868 lb-ft of torque.17 With everything finally assembled, we were finally ready to run Modern Mouse under boo 18 Stock LM7 5.3L-NA vs HP Performance Single Turbo (8 & 11.3 psi) The stock 5.3L was run with a set of long-tube headers, 36 psi injectors, and FAST XFI/XIM management system. Run in normally aspirated trim, the 5.3L produced 361 hp and 386 lb-ft of torque. Running with the Precision turbo on the single turbo kit from HP Performance resulted in 510 hp and 521 lb-ft of torque at just under 8 psi. Adding an intercooler and increasing the boost pressure to 11.3 psi resulted in a jump to 608 hp and 641 lb-ft of torque. At this point, the stock combination would benefit greatly from a cam swap.18 Stock LM7 5.3L-NA vs HP Performance Single Turbo (8 & 11.3 psi) The stock 5.3L was r 19 Modern Mouse-NA vs Twin CX Racing Turbos (12.8 psi) Though we ran Modern Mouse at lower boost levels, the final test resulted in peak power numbers of 963 hp and 868 lb-ft of torque at just under 13 (12.8) psi. That represented a gain of 448 hp and 361 lb-ft of torque over the normally aspirated combination. SOURCES Comp Cams/Fast 3406 Democrat Road Memphis TN 38118 800-999-0853 www.compcams.com Probe Racing 2555 West 237th Street Torrance CA 90505 310-784-2977 www.probeindustries.com Holley/Hooker 1801 Russellville Road Bowling Green KY 42101 270-782-2900 www.holley.com Procomp Electronics 605 S. Milliken Avenue Unit A Ontario CA 91761 909-605-1123 www.procompelectronics.com L&R Automotive 13731 Bora Drive Sante Fe Springs CA 90670 562-802-0443 www.lnrengine.com CX Racing 626-575-3288 www.cxracing.com « | 1 | 2 | View Full Article By Richard Holdener Enjoyed this Post? Subscribe to our RSS Feed, or use your favorite social media to recommend us to friends and colleagues!