KJ Jones
October 23, 2012
Photos By: K.J. Jones

On The Dyno

Of course, baseline dyno testing is a required element for this type of project. Since Evolution's new Shelby had been treated to a small assortment of bolt-on pieces prior to this effort, we accounted for the upgrades(JLT CAI, 65mm throttle body, long-tube headers, ATI 15-percent overdrive damper, and calibration) and used the ‘Stang's 750hp/780–lb-ft output as the numbers to beat with the blower upgrade.

The KB showed immediate improvement. With a conservative calibration (only 17 degrees of timing for 93-octane pump gas), rear-wheel horsepower registered 710 at 5,500 rpm, generated by only 18 psi of boost. A full pull (to 6,700 rpm with 19 degrees timing and 19 psi of boost) immediately followed, and the GT500 easily surpassed its best power output (with pump fuel and bolt-ons).

According to Jon Lund, this level of power would be "about it" for earlier-generation Shelbys, as the fuel system would be maxed out, and attempting 21 degrees of timing simply wouldn't be wise with 93-octane gas. Air/fuel for the '13 actually showed as rich during the initial tests, but Jon was confident that power would be in the 800s with fuel trimmed down and additional timing. One caveat in making 770 rwhp horses on the OEM fuel injectors and pumps is the scary fact that the pumps are at 96 percent duty cycle.

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"We would probably peg the duty cycle at 7,000 rpm," says Jon. "Just because the fuel system uses dual 5.0 pumps does not mean that the capacity is doubled. So give or take a few horsepower, 790 is about the maximum output with the factory stuff, 21-degrees of timing, and pump gas, and that's unbelievable." The Shelby's twin-Coyote pumps can be run as return-style. Reconfiguring the system as such is a great idea when you want to make even more steam safely.

A pulley change, Shell's URT Advanced race fuel, and more timing earned 4 more pounds of boost and its resultant 950 hp. "Based on the size of the engine and the big-boost capability of the Kenne Bell, it's clear the supercharger wasn't working efficiently with the 4-inch pulley," says Jon. The 3.6's efficiency range is about 17,000 rpm, and with the 4-inch wheel, blower speed was roughly 12,000 rpm at best. The dyno chart clearly shows the difference between the two pulleys.

The calibration for big power really didn't change (21 degrees of timing). However, adding Kenne Bell's 20-Volt Boost-A-Pump provided a little more pump volume, which allowed Jon to increase pressure. "Without the Boost-A-Pump, safely reaching 900-and-anything horsepower would be impossible with the stock fuel system. The injectors are basically screaming for mercy at this point," says Jon. Bigger is better! While this attitude isn't always true when it comes to modifying Mustangs, we definitely endorse the notion if it applies to replacing a '13 Shelby GT500's stock blower with Kenne Bell's gargantuan (3.6-liter) wind machine. The big blower garnered huge results in our landmark test.

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On the Strip

As we mentioned earlier, Evolution Performance now has a bonafide "rep" for building up and transforming Ford's latest bad-boy Mustangs into phenomenal ground-pounding beasts. After making record steam on the chassis dyno, the next step in our '13 Shelby GT500 evaluation was all about cutting the Pony loose on the quarter-mile at Atco Raceway. In preparation for this segment, Chuck equipped the 'Stang with a custom 7-quart replacement water/ice reservoir for the intercooler, swapped the OEM front brakes with lightweight stoppers from Strange Engineering, and swapped the stock 8.8 rear with a built unit that contains 35-spline axles.

With a 9.95/142.3 e.t. and mph already in the bag via the factory supercharger, the Shelby responded to the increased power by picking up 0.3 in e.t. (9.65) and 7 additional mph (149). It's important to note that this track performance was achieved in oppressive summer heat with the 'Stang weighing in at 3,854 pounds. We dare to say the 8s are inevitable. Sure, installing an automatic transmission, yanking out the seats and such, or simply adding a dash of nitrous oxide probably will carry the Kenne-blown brute into that hallowed territory. But that's going too far against the grain for Evolution Performance…and for us. Adding a Kenne Bell 3.6 makes this great car incredible. Bolt one on your new Shelby, and you'll instantly be in a great position to tear up the street and the 'strip.

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