The world of diesel performance is constantly evolving, but few builds are as awe-inspiring as Mario Monette’s “The Beast.” This 1988 Peterbilt 379, powered by a heavily modified CAT C15 engine, holds the NHRDA Hot Rod Semi MPH World Record at 120.35 mph. This incredible feat is a testament to the power and potential of the C15 platform when pushed to its limits.
The Mind Behind the Monster: Mario Monette and MHPD
Mario Monette, a seasoned diesel mechanic with over 30 years of experience and two degrees in Mechanical Engineering, is the mastermind behind “The Beast.” His company, Mario High Performance Diesel (MHPD), is a global leader in custom tuning for semi-trucks and heavy-diesel engines. Monette’s expertise and passion are evident in every detail of this record-breaking build. He and his expert team are doing custom tuning internationally, pushing the limits of diesel engines.
From C15 to C15-ish: Re-engineering a Legend
“The Beast” is more than just a powerful engine; it’s a testament to engineering ingenuity. While based on a CAT C15, Monette has extensively modified the engine, increasing its displacement to 17.3L from the stock 15L. He meticulously machined and polished the rods, designed custom copper head gaskets, and sourced recycled parts to create a truly unique powerplant. The stock crankshaft remains, highlighting the robust design of the original C15.
Fueling the Beast: A System Built for Extreme Performance
To feed the massive C15 Horsepower demands, Monette implemented a custom fuel system capable of delivering 2,000 gallons per hour. Four double fuel pumps ensure a constant 18 psi to the gear pump, which in turn supplies the injectors with 250 psi. This high-flow system, utilizing a 1″ hose, consumes an astonishing four gallons of fuel per quarter-mile run.
Force-Feeding Air: A Compound Turbo System for Maximum Boost
A compound turbo setup, featuring a 118mm Precision turbo and a 143mm Precision atmospheric charger, provides the immense boost required for this C15 engine build. Two wastegates, controlled by CO2, regulate boost pressure, currently set at 180 lbs. to enhance engine longevity. This intricate system ensures the engine receives the massive volume of air necessary to generate its incredible power.
Injecting Power: Custom Injectors for Unrivaled Fuel Delivery
Massive 14mm plunger injectors, nearly double the size of the stock 8mm CAT injectors, deliver an astounding 725cc of fuel per injection cycle—almost six times the stock injectors’ capacity. These custom injectors play a crucial role in achieving the C15’s phenomenal horsepower output. To manage this power, a custom-built standalone ECM, developed in collaboration with Dutch engineers, replaced the stock Caterpillar ECM, allowing the engine to rev to an impressive 4,200 RPM.
Beyond Horsepower: Giving Back to the Community
While “The Beast” is undoubtedly a remarkable machine, Monette’s dedication to using his creation for good is equally inspiring. He regularly raffles rides in the truck, donating all proceeds to a children’s hospital in Alberta. His passion for motorsports and his commitment to helping others make him a true role model in the diesel community.
Conclusion: A Testament to C15 Power and Innovation
“The Beast” stands as a remarkable example of what can be achieved with a CAT C15 engine, ingenuity, and a passion for pushing boundaries. Mario Monette’s creation is not just a record-breaking machine; it’s an inspiration to aspiring builders and a symbol of the enduring power and potential of the diesel platform. It showcases the incredible potential within the C15 engine architecture and serves as a powerful example of how passion and engineering expertise can come together to create something truly extraordinary.
