Mustangs and modifications have always gone hand-in-hand, and over the years manufacturers have developed many different power-adders to bolt into and onto the latest Mustangs. Granatelli Motorsports proprietor JR Granatelli has years of experience boosting Mustangs well beyond their factory capabilities, and with his company’s S197 bolt-on turbocharger system he’s done just that. Granatelli has the background in boost thanks to his former ownership of Paxton Superchargers, and he put that skill to the test when he developed this kit for the three valve S197 Mustang. 

On an otherwise stock Mustang, the kit is good for 450 rear-wheel horsepower on 91 octane, and if you’re lucky enough to be able to inject the 93 octane juice, you can put just about 500 big ones up on the dyno screen, all at a safe and reliable 8 to 10 pounds of boost. The kit comes with a 76mm Turbonetics turbocharger, TiAL wastegate, Granatelli bypass valve, and a stainless-steel hotside withg a 2.5-inch standard downpipe with an optional three-incher available. The cold side features aluminized tubing, twin Spearco intercooler cores, and the kit comes with all necessary sleeves, clamps, and hardware for installation. This system is capable of putting up to 800 horses to the ground from your Mustang if the car has been modified to support the additional power.

Granatelli does recommend calling the company if you are planning on pushing more than 9psi of boost as they have other modifications that they recommend to help support the higher power levels. As you can see from the video, in this particular installation (on JR’s personal ’05 GT) stuck 617 horsepower to the rollers along with over 646 ft./lbs, of torque. Perhaps even more impressive are the flat, broad horsepower and torque curves, meaning that lag will be virtually nonexistent with this setup. The system looks good and performs – what more are you really looking for in a performance bolt-on?