We like this a lot.
The Ford Mustang GT is a great little pony car. It's not as insane as things like the GT500 and doesn't come with the plain four-pot you get in EcoBoost models either. It's just right. With a 5.0-liter Coyote V8 developing 460 horsepower and 420 lb-ft of torque, it's a car to be neither feared nor ignored, but what if you want more? Companies like Roush will be more than happy to oblige, but if you happen to win a race, the whine of the supercharger will give away that your car has been upgraded. Pop the hood and your treachery becomes all the more apparent. But what if we told you that you could have Bugatti levels of power with no hint of it besides the fact that you're inexplicably way ahead of the other guy?
In the video above, Palm Beach Dyno takes what appears to be a bone-stock Mustang GT to its shop, and although the exhaust tone gives some hint of the upgraded performance, popping the hood shows what appears to be a totally stock engine bay. The stock airbox is there too, so it looks very stealthy. So what upgrades does it have? Featuring a 'Level 4' Hellion Sleeper package, this car boasts a twin-turbo upgrade with a pair of Precision 6466 turbos. Wondering where they are? You have to get under the car to see them, making this one of the stealthiest twin-turbo conversions out there. The motor itself is stock too, although the transmission has been upgraded by Rarefab.
After strapping the car to the dyno, the team starts off on low boost at wastegate pressure (6-7 psi) with 93 octane fuel, resulting in 620 hp and 505 lb-ft of torque. With 8 psi, you get 686 hp and 552 lb-ft, before 9 psi resulted in 708 hp and 565 lb-ft. Not bad baseline figures at all. With an E85 blend, things get turned up a lot. With this fuel and 10 pounds of boost, you can hear how much more aggressive it is and the dyno sheet proves it, with a max reading of 795 hp and 635 torques. At 14 psi, the results are an astonishing 923 hp and 687 lb-ft before 15 psi sees a magical 952 hp and 707 lb-ft. Best of all, these kits start at under $7,000. Take that, Bugatti.