Courtesy of Engine Builder.
We’ve seen a lot of crazy diesels over the years, and we won’t lie and say we haven’t described one or two as a “beast.” But regrettably, we may have been wrong in our analysis. This week’s spotlighted diesel is literally named “The Beast,” and that might even be an understatement.
The diesel performance world is vast and continuously growing, but souped-up semi-trucks are still one sector that is relatively small. You’ll find some crazy builds if you do some searching, but generally, the art of building a performance big rig for racing or pulling is difficult to get into. That’s why when you do find one, it’s pretty likely you’ll be taken aback.

“The Beast” is one such creation, which in 2018, propelled owner Mario Monette down the 1/4 mile to achieve the NHRDA Hot Rod Semi MPH World Record at 120.35mph. It might seem crazy to imagine a 15,000-lb. 1988 Peterbilt 379 reaching those speeds in only a 1/4 mile, but it makes more sense once you realize it’s being powered by a behemoth, 4,000-horsepower, turbocharged, CAT C15 engine under the hood.
It takes a professional to build something that impressive, and Monette was the man for the job. His career started in 1987 when he started working as a mechanic in Montreal. With two degrees in Mechanical Engineering and Program Engineering, 17 years as a diesel mechanic for Detroit Diesel, and tuning experience that stretches back to the late ’90s, Monette isn’t short of experience in any regard.

He moved to Alberta in 2010 and started his company two years later. Mario High Performance Diesel is one of the leading custom programmers in the world for semi-truck and heavy-diesel engine applications. Monette and his team of two other programmers collect data from vehicles internationally, using proprietary equipment, then build out custom tunes to make the said engines soar.
The Beast was born out of passion, and Monette built almost every aspect of the engine on his own. All the machining and engineering was done in-house with mostly used parts.