In 1996 Ford brought the modular engine family to the Mustang for the first time. In the 20 years since, the Mustang technology have come a long way. In 1996, the highest horsepower Mustang was the 305 horsepower SVT Cobra, with a naturally aspirated 4.6-liter DOHC engine. Modifying a Mustang has come just as far, if not farther since those days as well, and recently Brent White at Brenspeed pointed out just that.

Back in 1996, you could bolt a supercharger onto that new Cobra, and in most cases produce a little over 400 horsepower, with numbers probably in the mid to high 300s at the tires. With a pulley change, and a few more upgrades, you might have crept up on the 450-500 horsepower range, but that was pushing the limits of the stock internal components and what most street technology of the time was capable of.

Fast forward to today, guys like the Brenspeed crew can offer customers with new Mustangs a package like this Roush Phase 2 supercharger system. What’s so big about the Phase 2 upgrade? Above the Eaton TVS 2.3 based RoushCharger kit, the Phase 2 offers a smaller diameter supercharger pulley, a fuel pump voltage booster upgrade, a set of colder heat range spark plugs, and an updated Roush calibration for the computer. While that may not sound like much, the added boost and fuel from the Phase 2 upgrade can take any RousCharger equipped Mustang (or you can buy the Phase 2 system with supercharger) to over 700 horsepower. As advertised, Roush says this system makes 727 horsepower on an otherwise stock Mustang GT.

Stoked and curious to find out how much power this system really makes, White and the Brenspeed crew installed the Phase 2 upgrade on Brenspeed’s 2015 Mustang GT test mule. This car has participated in multiple events, and has served as the testing platform for nearly every S550 product that Brenspeed offers, including Roush supercharger kits.

When things settled down on the dyno, the numbers supported Roush’s advertised output, with 635 horsepower to the rear tires, which White says he estimates puts the power number at 747 horsepower at the crank. This car does have freer flowing exhaust, but no other modifications for this test to enhance horsepower.

The beauty of a modification like this is that the car retains full drivability. Cruising on the interstate, or through stop and go traffic, owners only “know” that there’s more power available, but the experience of driving the car remains the same. That is until you decide to stomp the loud pedal.

For those who have a car that’s already modified or want to go even further than this, the team at Brenspeed can help with that too. Nearly anything a customer can imagine, the Brenspeed crew can help them achieve. From parts sales, installs, and tuning, to full project planning and execution these guys do it all.

Twenty years ago, only the fastest cars made this kind of horsepower. These kinds of numbers required fully built engines, based on specialized blocks and parts, big lumpy cams, aftermarket cylinder heads with cavernous ports, street manners that pretty much sucked, and more maintenance than most of us wanted to admit or commit to. Today however, thanks to manufacturers like Roush and Mustang specialists like Brenspeed it would seem that the sky is the limit for your street going Mustang.