2021 Dodge Challenger RT 6.4L HEMI Conversion Build by MMX / ModernMuscleXtreme.com

Byron, Co-Owner of MMX Here. When I purchased my Challenger, I (and everyone else at the shop) knew it wouldn't stay stock for long. The warranty was voided within 24 hours by performing and in house PCM unlock, along with a custom MMX tune! I chose this platform (5.7 Base Car) for its high value. You get most all of the Scat Pack features, for a fraction of the scat cost. Within a few months, I became tired of the 5.7, and knew it was time to build a 6.4L engine to swap in. My goal for this car was to have a wicked fun daily driver, that was 10 second capable at the track.

This is the recipe I used to accomplish that goal: I started by sourcing a 6.4L SRT8 Block in good condition, and added our High Compression 2618 Drop in Piston and Rod kit. Final compression ratio came out to be a Pump 93 octane safe 11.7:1. We added our MMX HI-RAM 392 Camshaft, MMX CNC Ported Heads with PSI 1516 springs, and topped it off with an OEM 392 intake manifold with MMX Hellcat Throttle body adapter. Drivetrain modifications include a Pro Edge 4000 Stall torque converter, 17" Weld Ventura Wheels with 28x11.5 MT Bias Ply ET Street R tires, and an MMX Billet Diff Brace.

In November of 2024, I accomplished my goal and made a 10.98 Pass at 124MPH. It took only 7 passes down the track to hit my goal: 10 Second Naturally aspirated pass at FULL weight, on 93 octane. Like any good drag racer, enough is never enough. Stay tuned for Fall 2025 updates as I add a Holley Hi-Ram intake in the quest to go faster!

• BGE Block with MMX Drop-In 6.4 High Compression Piston/Rod Package (11.7:1 CR)
• MMX Hi-RAM Camshaft Kit
• MMX CNC Ported 6.4 Heads with PSI 1516 Springs, MMX Retainers
• Pro Edge 4000 Stall Converter
• MMX 6.4 Intake Manifold Swap Kit
• MMX Short Runner Valve Controller
• Stock Hellcat Throttle Body with MMX Adapter (92mm)
• MMX 15% Underdrive Balancer
• Stainless Works Headers
• MMX 3.09 LSD Upgrade
• MMX Billet Aluminum Differential Brace
• MMX PCM Unlock and Custom Tuning