If you’ve kept a close eye on Blue Oval news as of recent, you’ve probably noticed a trend featuring Ford’s stalwart six-speed automatic transmission in the headlines. That’s because racers of all experience levels are pushing 6R80 transmissions beyond its limits. Thanks to a strong aftermarket, Ford’s electronically shifted automatic transmission has been heavily massaged into the high 7s — and it doesn’t look like that’s the end of the road yet.
There’s no denying the capabilities of the 6R80, which is why it was an easy choice for Robert Jones III to swap into his ride. Though he doesn’t consider himself a professional racer and he doesn’t plan on running 7s in the quarter-mile, swapping to an automatic transmission in his 2009 Shelby GT500 was a no-brainer.
I wanted something that I could get onto the interstate with and ride smooth. – Robert Jones III
When Robert set out to purchase his first Shelby ’Stang, he knew it had to be a solid foundation to start his project on. Robert initially had an e.t. goal in mind – running 7s in the eighth mile, and he knew a Shelby GT500 would get the job done.
He purchased the car from its former owner in the state of Kentucky. At that time, the ’Stang featured some minor bolt-ons, and Robert was especially ecstatic when the owner claimed the car was capable of meeting his aforementioned e.t. goal.
Banging Gears With Bolt-Ons
Like all other GT500s produced from 2007-2014, Robert’s newfound Shelby came from the factory equipped with a six-speed manual transmission. He had always known that an automatic transmission was the key to success for his goals, but decided to stay on track with the manual combo in the early stages of the car.
“I had a handful of close races when it was just a bolt-on car,” Robert told us. “I ended up swapping out the factory supercharger for a ported 2.3-liter TVS supercharger from a ’13-’14 GT500. We upgraded it with larger fuel injectors and a Boost-a-Pump, and it made 754 horsepower at the rear wheels.”
One night, sadly, fate would not be on Robert’s side. He entered a local grudge-racing series which ultimately cost him more than just money. That same night, told us the engine threw a connecting rod, costing him the stock-bottom-end.
“It was at that time I decided to build the engine from top to bottom.” he said with determination.
Out with the old…
Robert purchased a built engine from a local forum member. The far more capable bottom-end would hold just about anything he would throw at it. Based on a factory 5.4-liter iron block filled with Manley billet I-beam connecting rods, Mahle forged pistons, Clevite bearings, ARP fasteners, a 5.4-liter Cobra Jet forged crankshaft, and billet oil pump gears. The short-block is topped by freshened cylinder heads fitted with a matching set of customs Bullet camshafts spec’d by none other than Todd Warren himself.
When all was said and done, his GT500 put down more than 800 horsepower and 800 lb-ft of torque at the rear wheels.
“This same short-block made more than 1,100 horsepower at the tires before I purchased it. Of course that was with a larger blower, which is why I am only making around 800.” he said.
Tear down began and removing the old components were the first step. For Robert, the question remained – To keep the six-speed, or not?
Revamping the tough-as-iron 5.4 in his Shelby got the wheels turning for Robert and he decided to go for a pioneering automatic transmission swap.
“What also made me really want to do it is that I drag race a lot,” he explained. “I was trying to decide what transmission to use during the rebuild. I was considering picking up a 6R80, since I had never heard of another ’07-’09 GT500 with one. Everyone kept telling me it couldn’t be done, so I set out to do what they told me couldn’t be done. They would tell me that it’s too expensive, or that I couldn’t get the transmission’s computer to work with my gauges, or that I had to swap the console out – because it hadn’t been done, they were saying I couldn’t do it – period.”
Doubt instilled in Robert regarding his endeavors only fueled the fire even more. On a mission to “prove ’em wrong,” he contacted U.S. Shift and entertained his transmission swap concept. After the company gave him its blessing, he immediately got started.
His longtime friend and fellow Mustang enthusiast, Michael Franks, owner of BST Performance, headed up the install for his Shelby. Robert tells us that he wanted the installation done the right way, the first time, which is why he enlisted Michael to do the job, which is easier than you might suspect.
“We used everything we could from a ’11-’14 Mustang GT,” Michael said. “Robert went to his local Ford dealership and purchased a factory crossmember. He also purchased a Circle D torque converter and a Dynotech one-piece aluminum driveshaft, both of which were designed for a 2011-2014 Mustang.”
It may look like a giant wiring mess, but don’t let that deter you from doing the swap yourself. All 16 of those wires are nicely bundled into one harness for convenience.
Because the ’07-’09 Shelby GT500 is also based on the S197 chassis, Michael says everything fit like a glove as one would expect.
“We reused all of the bolts for the transmission cross member, but we had to use shorter bolts for the flex plate,” he detailed. “The reason is because the manual transmission flywheel uses longer bolts, and an automatic transmission flexplate uses shorter ones. What we love about this transmission is that all of the wiring for the electronic solenoids that the 6R80 uses is combined into one transmission harness.”
Part of Robert’s upgrades came in the form of an all-new VMP Performance 2.3-liter Gen2R TVS supercharger.
Michael says that the Quick Shift TCU controller from U.S. Shift allows for a plethora of options for the swap.
“Coyote cars use a different speedometer output. The Coyote cars are analog, and the GT500s have a digital signal,” he affirmed. “Once we got the transmission functional, we used the Quick Shift TCU to calibrate the speedometer. The speedometer works by using an all-positive signal, which means we had to use a capacitor in series with the signal wire. It will chop the negative signal, allowing for a completely positive signal from the TCU to the ECU.”
He also explained that the Quick Shift has the option to integrate select shifting as well, making a paddle-shift option plug-and-play. Robert plans to eventually perform a ’13-’14 Mustang GT shifter swap to enable his GT500 to utilize those options, but for now he’ll settle for some upgrades — like a billet intermediate shaft, high-stall torque converter, and a deep pan — ensure durable performance and reliability for eight hours of commuting with no issues or leaks.
“Everything worked out perfectly, just like we had planned,” he said with a sigh of relief. “The difference between me and a lot of people is that I drive my car about four hours one way every weekend. Most people who have cars like this get them just to play with. They don’t have to drive out of town like I do, and that was the difference – I wanted something that I could get onto the interstate with and ride smooth, and I didn’t have to worry about switching gears with a manual valvebody or anything.”
Robert’s goal is to find the limits on the 6R80 six-speed automatic transmission. Coupled with a plethora of BMR Suspension components, his car is expected to exceed the 9.5-second pass he made late last year thanks to the swap. For a 4,050-pound street car that makes 800 horsepower at the rear wheels on 93-octane, we’d say this is only the beginning for Robert and his Shelby.
To keep tabs on Robert’s endeavors and see if he achieves his goals, you can follow along on his Instagram account here .