Michael Galimi
November 10, 2010
Photos By: Anthony Caggiano

The '11 Mustang GT with the 5.0L engine is everything we hoped it would be. It packs a 412hp 5.0, has a great sound, and is a great performer in factory trim. In the past six months, we've seen these cars eclipse the 10-second barrier with nothing more than bolt-ons ("10s Too Easy," Sept. '10), and one guy ran 9s with a serious nitrous combo and a C4 transmission.

Despite this, the 5.0L Ti-VCT engine is still young, and the aftermarket is ramping up quickly to supply parts for it. One company in the driver's seat is AmericanMuscle.com. The company is a serious player, known mainly as a mail-order warehouse, but the recent addition of Bama Custom Tuning to the family moves it into the tuning and building market as well.

Photo Gallery

View Photo Gallery

The company picked up a new 5.0L GT, not just for fun but as a means to learn and develop parts for the new-generation hot rod. The first wave of performance shows the potential of the 5.0L, but we noticed that most shops opted for the six-speed manual transmission. Would the automatic perform as admirably as its manual brethren?

AmericanMuscle was willing to find out with its purchase, a Grabber Blue '11 5.0L armed with the new 6R80 auto transmission. "We decided to get an automatic 5.0L because we had to learn more about the car for our customers," stated Chris Rose of AmericanMuscle. Along the way, the Bama Custom Tuning division worked with SCT to unlock the automatic shifting controls-more on that later. The goal was (and still is) to bolt-on the popular upgrades and chart the progress step-by-step so when a customer inquires about a particular component, the AmericanMuscle representatives will know exactly how the parts perform and fit.

Before any parts were changed or the computer was tuned, AmericanMuscle set out to get baselines on the in-house chassis dyno and on the drag strip at Maple Grove Raceway near Reading, Pennsylvania. In stock trim, the GT unleashed a 13.02 at 110 mph and 13.03 at 109 mph with Bama Custom Tuning's Mike Wilson at the helm. Back at AM headquarters, the car was hooked up to the Dynapack chassis dyno (a DynoJet will be installed by the time you read this issue). The in-house dyno is used to develop tuning files and randomly test parts and pieces from various manufacturers. The test mule produced 363 rwhp and 331 lb-ft; pretty much what is expected from an auto-backed 5.0L.

Photo Gallery

View Photo Gallery

The dyno results are interesting with a 6R80 automatic car, to say the least. The new transmission lacks a 1:1 gear ratio, which is the traditional gear to used for dyno testing. The closest gear ratio in the 6R80 is Fourth, with a 1.14:1 ratio, and that is what AmericanMuscle used for its baseline dyno testing. Some shops use Third gear due to the 1.52:1 ratio. The team did determine that the more accurate technique to dyno test with the 4.10s, however, is to run the car in Fifth gear as opposed to the Fourth gear dyno pulls with the stock 3.15s.

One note for on-track racing-there is no Overdrive On/Off button. The Tow/Haul button is useless on the track because the computer switches to a tune table that kills performance. The stock 3.15 gears work well as the transmission stays in Fourth through the traps. But once you go to something steeper, like 4.10:1 gears, then the transmission will shift into Fifth to make it through the quarter-mile, thus killing performance. That problem is easily fixed in the aftermarket tune, and Bama set this car to stay locked in Fourth gear at WOT.