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Prepping a Mustang 6R80 Automatic Transmission for 1,000 HP
Building a high-horsepower dragstrip Mustang used to mean sourcing a beefed-up, old-school two-or three-speed automatic transmission. While great for the quarter-mile duty, the older slush boxes don't have overdrive and aren't compatible with today's high-tech vehicles.
Fortunately, Ford's 2011-2017 Coyote-powered Mustangs came with a surprisingly stout transmission from the factory: the 6R80. Racers are finding that, with a few choice modifications, the automatic six-speed unit is a solid partner for serious drag race duty. This means a beefy, computer-controlled automatic transmission with highway-friendly overdrive is finally a reality!
As we prep our ProCharger-equipped 2011 Mustang for 8's in the quarter, we knew the 6R80 needed some attention to handle our expected 1,000-plus horsepower. To that end, we fortified our slushbox with a Power by the Hour (PBH) Performance Intermediate Shaft, Exedy Stage 2 clutches, and a Sonnax Zip Kit.
The PBH 6R80 Performance Intermediate Shaft was developed in partnership with Boninfante Friction, a supplier of drivetrain parts for Top Fuel dragsters—so if we break this thing, we're doing something wrong. Rated for over 1,000 rwhp, the shaft is machined from aerospace material and finished with Boninfante's "Nitrofinish" process to remove stress risers and improve product durability.
The strongest shafts won't mean anything if the transmission's clutches slip and burn up, so we chose Exedy's Stage 2 Clutch Pack kit for 6R80 transmissions. Exedy claims a 40% increase in clutch capacity over their Stage 1 kit. This increase in holding power and transmission durability is essential at the horsepower levels we're planning.
We're about as useless as an LS-swapped Fox-body when it comes to automatic transmissions, so we enlisted the expertise of Chino Hills Transmission to help us with the install. As you'll see in the photos and captions, we're glad we knew professionals handled this job!
Chino Hills Transmission
14182 Central Ave #L
Chino, CA 91710
Power by the Hour
Photos By Mike Morgan