Put a Hellcat Blower on Any Third

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Ever since Dodge came out with the 707-hp Hellcat Hemi in 2015, hot-rodders have been trying to break the code on how to convert an ordinary naturally aspirated 3rd-generation Hemi to a supercharged Hellcat. It's not a question of whether it can be done. There's always going to be that person who just keeps swapping OE Hellcat parts onto a 5.7-liter or 6.4-liter Hemi until it finally works, throwing cost and trouble to the wind in an irrational bid to be the first. That's fine for Mister Money Buckets with more ego and cash than smarts, but what about the rest of us? We don't have the complete answer on that yet, but at the 2022 SEMA show, we did see important progress on that front from a company called CFR Performance.

At a price of $399, CFR Performance has begun offering part number HZ-7760-M, which is a pair of billet-aluminum spacer plates that are mounted between the Hemi's cylinder head intake ports and a donor Hellcat blower assembly (either the 2.3-liter Hellcat variety, the 2.7-liter Redeye/Demon variety, or the 3.0-liter Hellephant version). Now that the Hellcat's IHI-sourced, positive-displacement compressor is becoming more available in salvage yards, it has become a target of Mopar tinkerers everywhere. CFR's conversion spacers allow for the Hellcat's perimeter bolt pattern to work on the naturally aspirated Hemi's centrally positioned intake manifold bolt holes (2011-up VVT-equipped 5.7-liter and 6.4-liter Eagle and Apache only).

The CFR spacer kit is so new that it doesn't appear on the company's website, so you'll need to call them up and ask for it by name. In fact, there's no information to be found about it anywhere, so we researched the topic and discovered that Modern Muscle Xtreme (MMX) has been working on the Hellcat blower conversion problem for a couple of years now. In fact, MMX offers a similar spacer conversion kit, along with many of the other items needed for the conversion in a collective kit, and by our reckoning, this makes them the leading authority on the Hellcat-blower-swap conversion topic. (Check out a cool video on the subject produced by MMX's Byron Walker. )

We were drawn to CFR's booth at SEMA because they were displaying a gray 1975 Plymouth Duster with a 5.7-liter Hemi conversion that was equipped with a Hellcat blower assembly. The car was mobbed by Mopar fans and we struggled to get a closer look, but when we later checked the web for videos of the car cranking, running, driving, or racing, we couldn't find any. A call to CFR didn't add to our information, so we checked with MMX and found the company's Byron Walker full of important details on the Hellcat blower conversion. We also found a successful conversion of a 5.7-liter Challenger with a Demon blower (it's gone a best quarter-mile of 11.79 at 118 mph) that was performed at home by Mopar master tech Michael Bass who goes by YouTube handle TA Life Fallen Angel. You can see him drive it here, and watch him explain the mods you'll need for the job here.

Byron Walker of Modern Muscle Xtreme advises users to enter the Hellcat blower proposition with eyes wide open: "We're going to offer a few parts on the website but we're never going to offer a full kit per se, as that is very hard to do between 5.7s, 6.4s, and Chargers and Challengers. There are too many variations of everything for us to offer a complete kit and bolt it on to your car and go. This is going to require fabrication, it's going to require some knowledge, and a little bit of skill to make this work." So just how much work and money does it take? Walker points out that at this time it's still easier and cheaper to bolt on a new blower kit, such as the one from Procharger, but for those with the fabrication chops the cost for a Hellcat blower conversion is between $6K and $8K, depending on the cost of the donor unit.

As it turns out, the adapter plate kit to accommodate the blower's unique bolt pattern is just the first hurdle in the conversion. MMX's Walker states that the next major need is the blower/accessory drive itself (MMX offers a conversion kit, $349.42), which is shown above.

The third major roadblock—and it's a big one—is a controller for the supercharger's bypass valve. Today's efficient positive-displacement superchargers use an internal bypass valve to eliminate parasitic loss from cruise boost; these valves operate like a throttle body in reverse, only closing to trap boost inside the compressor housing when your right foot goes down. MMX's Smoothboost controller is shown above ($599.99).

Beyond those major barriers are a host of smaller obstacles that include providing an oil-fill provision, positive crankcase ventilation (PCV), relevant plumbing for vacuum operation of the master cylinder, heat exchangers, a coolant transfer pump (above), larger injectors, Hellcat supercharger coolant reservoir, a bigger fuel pump or pump booster, a coil-pack harness extension kit (for the reversed orientation of the coil packs), Hellcat valve covers (or a viable substitute), blower pulley kit, colder spark plugs, and a Hellcat MAP sensor. Completed conversions will also need advanced tuning capability to iron out the drivability and tune.

On episode 26 of Engine Masters, find out if you can stuff 25 psi of boost into a cast-piston, stock-crank short-block and have it live! Watch as David Freiburger, Steve Dulcich, and Steve Brule strap a ProCharger centrifugal supercharger to a bone-stock Chevy 350 bottom end and keep stepping up the boost to find the breaking point. Sign up for a free trial to MotorTrend+ today and start watching every episode of Engine Masters, plus much more!