Lucas Bell 
For as long as we have had cars, there have been folks trying to make them faster. And while we have evolved past the early days of hot-rodding, many of the same principles apply to this day. This is especially true when it comes to adding horsepower, something that the aftermarket has gotten incredibly good over the years. That said, things are changing in the auto industry. Automakers have begun locking down the ECUs that control our vehicles in the name of cybersecurity, which has proved disastrous for our friends in the tuning industry. Both the C8 Corvette and the entire line of full-size GM SUVs are currently un-tunable, as is the new Ford Bronco. If you are willing to drive a vehicle that is a few years old however, there are still plenty of solutions for you. Take this GMC Yukon tuned by Katech for example, which makes more than double the rear-wheel horsepower that it left the factory with.
This particular GMC Yukon is a 2015+ generation model, and not one of GM’s current offerings. Because of this, there is none of GM’s Global B Architecture attached to the 6.2L L86 V8 engine found under the hood. In factory spec, the engine comes rated at 420 horsepower and 460 lb-ft of torque. When the tuning-madmen at Katech strapped the GM SUV to their dyno, they found that it produced 284 horsepower at the rear wheels. This clearly wasn’t enough for the owner of this truck, as they opted to install an Armageddon twin-turbo kit. Unlike Katech’s normal builds that utilize a supercharger, this kit comes with a pair of Garrett GT3076R turbos.
In order to support the forced induction, the Armageddon twin turbo kits has been supplemented with an LT4 fueling system, two Armageddon 45mm wastegates, a 52mm blow-off valve, and an aluminum high-flow intercooler. To let those gasses escape, this GMC Yukon also features a Kooks downpipe, charge pipe, and headers. Katech also took the liberty of building the engines internals to help bolster the reliability of the SUV. Running just 12 psi, this GMC Yukon laid down 625 horsepower to the rear wheels.
For those keeping score at home, this represents gains of over 340 horsepower at the rear wheels. There is a lot of torque too, with the SUV providing 660 lb-ft of twist at the wheels. Despite the fact that this GM SUV weighs in around three tons, that is some serious shove. Of course we wouldn’t expect anything less from our fellow Detroiters at Katech.
So while the tuning industry may be struggling to cope with the reality of new cars, they still are more than capable of building crazy machines. If you can’t quite get over the fact that General Motors doesn’t want you playing with their new cars, you can always get a used one. If you happen to call the folks at Katech, that aging 4×4 should have no issues dusting the latest offerings. And as we all know, that is what is really important when buying a family hauler. It is literally in the name.
