This Triple-Turbo BMW 335d Runs 8s With Diesel Power

How Matt Santjer’s 335D Changed The Way We Look At Diesel Performance

Social Post Copy: Matt Santjer bought his 335d for the same reason most people do, because it made sense. Good mileage, comfortable ride, and something different from the usual diesel truck. What didn’t make sense, at least at the time, was how far it would go. Over the years, that daily driver turned into an absolute animal that now sits at the center of an entire performance platform.

Matt didn’t come from the Euro scene. His background was rooted in Power Stroke and Cummins platforms, where big displacement and low-rpm torque rule everything. About ten years ago, that focus shifted toward BMW diesels, specifically the M57 platform. On the surface, it’s a 3.0L inline-six with an aluminum block, common rail injection, and factory twin turbos. Underneath, it’s a completely different challenge: higher rpm, less rotating mass, tighter packaging, and far less margin for error when things go wrong. That difference is what kept him invested, because it forced a different way of thinking.

What started as a daily quickly became a test bed. Early on, one of the biggest breakthroughs came from developing a dual CP3 fuel system for the M57. That alone changed what people thought was possible with these cars. Paired with larger S&S injectors and a heavy shot of nitrous, the car pushed into the 675 wheel horsepower range on a stock bottom end with factory turbos. At the time, that wasn’t a common result for the platform, and it marked the point where the car moved beyond being just another modified diesel BMW.

From there, the focus shifted toward making that kind of power without relying on nitrous. That meant rethinking the combination entirely and putting more emphasis on airflow, fueling efficiency, and combustion control. Let’s be clear here: the process was anything but clean. Matt went through 15 to 20 engines early on, pushing the limits of factory rods and pistons and finding out exactly where those limits were. Bent rods, damaged pistons, and general wear weren’t setbacks as much as they were part of the learning curve. Instead of guessing, he leaned into data, using cylinder pressure monitoring and combustion analysis to better understand what the engine needed to survive at higher output levels.

All of that experience shows up in the current setup. The M57 now runs an OEM forged crank with SPD rods and pistons inside a sleeved block prepared by Kill Devil Diesel. The head remains largely factory, paired with SPD valve springs, and is topped with a billet valve cover. It’s not a complete departure from the original design, but rather a reinforced version of it, built around what years of testing proved necessary.

Air and fuel are where the combination really comes together. The car runs a triple turbo system developed in-house, supported by dual CP3 pumps and S&S injectors. Charge air moves through an SPD-built intercooler using a large Garrett core that Matt welded on his own, and of course, nitrous is still part of the setup through a Nitrous Express Maximizer system. It’s used strategically rather than as a requirement to make power, and it works well.

On fuel alone, the car has produced 787 wheel horsepower and 915 lb-ft of torque. With nitrous, it has reached 1,081 wheel horsepower and 1,352 lb-ft, and based on current track performance, the combination is now operating around the 1,200-horsepower level. Those numbers carry more weight when they’re tied to a full-weight sedan that still retains its original character.

Getting that power to the ground required a different approach than what most truck builds rely on. The factory transmission was replaced with a ZF 8HP70 sourced from a later 535d, controlled by a TurboLamik standalone system. Internally, it uses billet E and C drums, increased clutch capacity, Alto G3 clutches, and an SPD torque converter. A transbrake rounds out the setup, allowing the car to launch consistently without sacrificing durability.

The rear of the car still relies on the factory 2.81 differential, upgraded with a Wavetrac limited-slip unit, Driveshaft Shop axles, and a carbon-fiber one-piece driveshaft. Like the rest of the build, it’s a combination of OEM engineering and targeted upgrades rather than a complete redesign.

The suspension follows that same philosophy. KW V3 coilovers handle both street and track use, and the car still sees time on the road course at Virginia International Raceway. Outside of wheel and tire changes and minor brake adjustments to clear the drag setup, the configuration remains largely the same regardless of where the car is being used.

Inside, the car retains a full interior with Recaro front seats added for support. It hasn’t been stripped or turned into something purpose-built for a single type of racing. It still functions as a complete car, just one that happens to operate at a much higher level than it was originally intended to.

For years, Matt drove the car to Outlaw Diesel Super Series events, competed in the 6.70 index, and drove it home with tools in the trunk. That approach speaks to how the car was built, not just to perform but to function. Even as the power level has increased, that mindset hasn’t completely gone away.

The car has since moved into the 5.90 index class, a goal that took years to reach. It has made over 100 passes in the 5.9x range and recently secured a second-place finish at Rudy’s Truck Jam to open the 2026 season. The best eighth-mile pass to date stands at 5.75 seconds at 128 mph with a 1.39 sixty-foot time. In the quarter mile, even on a conservative pass, it has run 8.97 at 160 mph, with additional performance still available when the car is pushed harder.

Santjer Performance Development grew alongside this car. What began as solving problems for a single build turned into a business focused on engineering and manufacturing the components needed to support higher power levels in these platforms. The lessons learned from this car directly shaped the products now used by others pushing similar combinations.

The 335d continues to evolve, but the core idea remains the same. It’s a full-weight, street-driven diesel BMW that can compete at a high level without losing what makes it usable. It doesn’t fit neatly into the expectations most people have for diesel performance, and that’s part of what makes it relevant.

Diesel performance doesn’t start and stop with trucks, and this car is a clear example of how far it can go when someone is willing to approach it differently.