Michigan-based tuner Katech Performance is very well-known for its Chevy Corvette and Camaro engine upgrade programs, but owners of full-size General Motors SUVs like the Chevy Tahoe and GMC Yukon can get in on the fun too.
Katech Performance recently shared a video on its YouTube page of a customer’s fourth-generation GMC Yukon undergoing some performance validation testing prior to delivery. This particular customer spared no expense on their GMC Yukon, commissioning Katech to slap together a fully custom twin-turbo engine build based on the SUV’s factory 5.3L L83 V8. Some of the more notable engine upgrades include new pistons and rods, a custom Katech camshaft, CNC ported cylinder heads, a CNC ported throttle body, a Katech billet wet sump oil pump, LT4 injectors, an LT4 injection pump and twin Garret GT3076R turbochargers with Turbosmart 45-mm wastegates.
This custom twin-turbo L83 V8 was dyno tested at 626 horsepower and 660 pound-feet of torque on Katech’s own in-house dynamometer. For reference, a stock L83 V8 engine produces just 355 horsepower and 383 pound-feet of torque from the factory – and that’s crankshaft horsepower, not wheel horsepower like Katech is measuring here. That means the tuning shop managed to pump the L83’s numbers by more than 340 horsepower. It takes a lot of power to move a big, heavy, aerodynamically challenged SUV like the GMC Yukon with any gusto, but we think this custom L83 is up to the task.
Katech also offers less expensive upgrade packages for other GM SUVs and trucks like the Chevy Silverado, for example. The company’s supercharged Stage 1 kit, which targets a crankshaft output of around 650 horsepower, is perfect for buyers who want more performance out of their large GM truck or SUV, but don’t need a somewhat over-the-top build like this twin-turbo L83.
Check out the video embedded below to see this twin-turbo GMC Yukon in action on Katech’s dyno.