Steve Turner
Former Editor, 5.0 Mustang & Super Fords
December 15, 2010
Photos By: Derek Perez

When we last left Lethal Performance's '11 Mustang GT project car, it was transformed from mild-mannered stocker into a bolt-on, nitrous-breathing contender. With just a few bolt-ons and a whiff of the horsepower gas, this car was a serious street machine.

Those modifications, however, were simply a test to see how the car responded. The goal all along was to add boost and hold on for dear life. To make that happen, Lethal returned the car largely to its stock configuration, save the one-piece DSS driveshaft and Magnaflow after-cat exhaust. With that done, it was time for us to head back down to Power By The Hour in Boynton Beach, Florida, to watch the car go under the knife and receive Ford Racing's new Whipple supercharger kit.

Lethal has long been a proponent of Whipple's twin-screw superchargers, and has used them on several prior project cars, including its recent 5.0&SF cover star, a '10 GT500 project car.

"Being that we've got an excellent relationship with Whipple as well as the fact that we ran their twin screws on our past project cars it was a no brainer who's kit we were going to run once they became available for the 5.0," said Jared Rosen of Lethal Performance. "Not only do their kits provide awesome power but we know that the support we'll receive with the kit is of the highest level as well."

Likewise, Ford Racing Performance Parts has long offered complete supercharger kits based on Whipple's superchargers. Naturally, FRPP's kit was the first variation of Whipple blowers available for the new Coyote 5.0. However, even for the factory's performance arm there were challenges to creating a kit for the all-new engine.

"Accessory drive was a challenge, as well as hood clearance. This is common for any positive displacement valley-mounted supercharger kit," Ford Racing's Jesse Kershaw explained. "Also adding the second ACT sensor. This is critical to offering a warranty on our 525hp kit. By adding a second air-charge-temperature sensor downstream, we are able to monitor what's going on with air charge as well as the incoming air through the mass air. With only one, which is typically installed in the intake, the PCM is only getting half of the information we need to fully calibrate the kit. Only the Ford Racing kit features the second ACT sensor."

Besides the factory levels of quality put into the mechanicals of this kit, it's the tuning that Ford Racing is most proud of. "Tuning is extremely critical with this engine. Higher compression ratio, more processor functionality, and twin independent variable cam timing all play a role in maximizing power but add to the difficulty of calibration," Jesse said. "The second ACT sensor requires all-new software in the processor not just a calibration. It's akin to a normal calibration being a Microsoft Word file, ours is like downloading a new version of Microsoft Word with new functionality that accepts our file. No one else can do this outside of Ford."

In practice, the kit's results are quite impressive. The driveability surpasses that of the stock car. The car's response is improved and the annoying skip-shift is a thing of the past. Moreover, the car picks up gobs of power and torque across the entire powerband, essentially transforming the already impressive Mustang GT into a stealthy street fighter capable of going toe-to-toe with even pulley-and-tune GT500s.

"The 5.0 from the factory is actually quite impressive to begin with. It's similar to how the GT500 feels but without the blower whine. Being able to run 12s and rev the car over 7,000 rpm just how it's delivered is great. Now imagine adding another 150-plus-rwhp to the car," Jared enthused. "It's a completely different beast and goes from a 12-second car to a 10-second car. What's amazing though is how well the car drives with the blower. It still cruises around just like stock until you mash the pedal to the floor. At that point the power instantly comes on and even though it's a major jump in power the transition is still surprisingly smooth."

With that kind of impressive performance on tap, you'd think Team Lethal would be happy to leave its in-house GT just as it sits. Not so for this bunch. These are the guys that fearlessly tore into brand-new GT500s. "As you know from our '10 GT500, the project goals seem to change a bit. It starts out as an idea for a street car that showcases the parts needed to make the car fast and appeals to the majority of the car owners but somehow molds itself into an all-out, race-car project," Jared confessed. "As much as my business partner Jonas doesn't want to hear it, I'm sure our 5.0 isn't going to be much different. The only thing I can see it this project happening in more of a step-by-step process rather than an overnight transformation. In the end we'll be happy with whichever way it goes-and then it's on to the next one."

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On The Dyno

StockWhippleDifference
RPMHPTQHPTQHPTQ
3,000167.18292.67216.18378.4449.0085.77
3,500214.15321.34269.12403.9554.9782.61
4,000257.14337.63322.80424.5465.6686.91
4,500298.69348.61371.71433.0373.0284.42
5,000326.23342.68415.50436.3289.2793.64
5,500350.10334.32459.20438.47109.10104.15
6,000353.92309.81490.39429.24136.47119.43
6,500363.74293.91514.53415.76150.79121.85
7,000n/an/a525.99394.62n/an/a

Things don't always go laboratory smooth for us. We were on the cutting edge of the FRPP/Whipple kit and ended up starting out with a preliminary ProCal tune with an aggressive knock sensor profile. With this first program and Magnaflow mufflers as the only other mod, the car made 505 at the tire. However, FRPP wanted us to try its final calibration for the story. Naturally, Lethal had already started modding the car, and had reinstalled its off-road X-shape crossover, so there is more than one change going from baseline to the final 525-rwhp number. Still it gives a good idea of the capabilities of this kit, which added triple-digit gains from 5,300 rpm on.