Is Bill Hahn a true fan of turbocharging? In his words, "No engine is complete without a turbocharger (or two!)". Because turbochargers use a soft coupling between the engine and the turbocharger (exhaust gases), the power onset is always a linear increase of power that isn't sudden or abrupt, and doesn't tend to shock driveline components.
Durability and drivability, with phenomenal horsepower potential, are certainly the clear advantages of turbocharging. Again Hahn adds, "With turbos, we can take near stock engines and in some cases get two times the stock power out of them, while still achieving reasonable durability. How is this possible? A turbo is able to provide a denser air/fuel charge into the cylinder. With a turbo system, we don't cause a more violent explosion in the cylinder; rather, we create additional power via a longer power cycle due to this denser charge. A normally aspirated motor's combustion event ends with the piston still on its way down. With turbocharging, there is a longer combustion event that is continuing to push the piston down for a longer period of the power stroke and crankshaft rotation. As a result, there is more power without dramatically compromising the durability of the engine through violent pressure rises. In today's times, better engines, better engine management systems, and better turbos have combined to produce the golden age of turbocharging."
This twin-turbo system is undoubtedly outstanding design and craftsmanship coupled with world class daily drivability and extreme horsepower. This twin-turbo GTO delivers stock-like mileage and 550 hp at the flywheel. That type of capability was not available until the emergence of the LS1, and now the LS2s have appeared on the market.
Referencing the twin-turbo GTO's ability to create this exceptional performance package, Rick Bottom sums it up nicely, "The car has the stock cats with the Corsa noise cancellation technology. It's whisper quiet. When you stand on it, there's some sound, but it's really about power and refinement. If you're rolling along in Second, it breaks the tire loose. In Third gear the motor is really working strong ... each gear pulls harder and harder. The old GTO felt bad but it worked. The new GTO is really fast, but it doesn't feel as fast because it's more effortless. The new cars hook up and go. There is no comparison in the performance."
Hahn's turbo kit allows the LS1 to produce 476 rwhp. Editor Jensen spent some time behind the wheel of this beast on the backroads of Yorkville and found it to be a refined rocket with excellent spool-up and enough power and torque to deceptively move the big GTO. Not so much like a rip-snortin' F-body--more like an M5 BMW on steroids!