Ultimate Mopar Swap
Installing a 700hp Hellcat crate engine in a ’17 Ram Rebel
Ever since Mopar released its Hellcat V-8 as a crate engine last year, Ram enthusiasts have considered the possibility of another supertruck that could revive the performance passions the iconic SRT-10 models produced from 2004 to 2006. If you remember, those regular-cab models came with a 500hp, 8.3L, all-aluminum
Viper V-10 engine and six-speed manual transmission. Ram also released a Quad Cab version with an automatic transmission. Both models were street brutes with more than 500 lb-ft of torque available through much of the power band. However, with a Hellcat under the hood, more than 500 lb-ft of torque would be available at the rear wheels—not just the flywheel!
Rated at 707 hp and 650 lb-ft peak torque, the 6.2L supercharged Hellcat engine has all the tools to create another uber-performance street truck, if you know how to drop one in a late-model platform. Dakota Customs, located near Rapid City, South Dakota, specializes in Hemi conversions and has swapped numerous Hellcat engines into Jeeps. But this was the shop’s first Ram project, which presented its own set of challenges.
“Getting the engine to run wasn’t a big problem, but there were specific calibrations that had to be addressed,” shop manager Dan McKeag says. “For example, the torque management program for the transmission shifts. There are cooling fan differences, ABS brake differences, and more.”
Physically, there were few issues when it came to replacing the stock 5.7L Hemi with the Hellcat. The team retained the stock eight-speed automatic transmission, flexplate, and torque converter. This swap was performed on a four-wheel-drive truck, although it would be just as uncomplicated with a rear-wheeldrive model. Grinding was needed to clear the alternator, and a little surgery was required on the firewall to make room for the intercooler fluid lines.
The key to mating the Hellcat with the Ram is the wiring harness. Dakota Customs used a Hellcat PCM and fused the stock wiring harness with a Hellcat automatic harness. The team basically laid out the two harnesses, noted the differences, and consulted wiring diagrams to make sure the correct pin connectors were utilized.
Once the Hellcat engine was swapped in place, the PCM could be unlocked and recalibrated with the necessary information that keeps both the truck and the engine happy. For example, the Hellcat requires a multi-phase fuel pump to keep up with the supercharger demands. Dakota Customs couldn’t use the stock Ram pump, so the crew swapped in an Aeromotive dual fuel pump and regulator. Also, the Ram comes with an engine-driven fan, but Dakota Customs wanted an electric fan to address cooling issues. The crew found one from an older Ram V-6 pickup and calibrated the PCM to operate it accordingly.
The swap almost doubled the horsepower and torque produced by the factory 5.7L Hemi. In addition to the performance upgrade, Dakota Customs added bold SRT Hellcat graphics and a more aggressive wheel-and-tire combo, with 35-inch Toyo tires wrapped around 22-inch SRT replica wheels. With these looks and power, there was only one more thing to do—think of a name. The Ram Cat? The Hell Ram? The Rebel Hell? The possibilities are endless.
A 707hp Hellcat V-8 engine stands ready to be swapped into a new Ram pickup.