BMW's S58 engine, featured in the outgoing X3M, X4M, M2, M3, and M4, has become a canvas for enthusiasts and performance aficionados to push the limits of power. In this article, we explore the engine's innate capabilities and its transformation into a powerhouse capable of handling remarkable horsepower and torque figures.

Engine Breakdown:

The S58 engine is an Inline-6 configuration with twin single-scroll turbochargers, boasting a compression ratio of 9.3:1. Its bore and stroke measure 84mm x 90mm (3.31″ x 3.54″), housed in an aluminum, closed-deck engine block. The S58’s aluminum cylinder head features a 3D-printed core, while the rotating assembly comprises a forged crank, rods, and pistons. With a redline set at 7,200 RPMs, the S58 is already a formidable force on the road. With all of this information, you may ask, “How does this motor compare to the outgoing Gen 2 B58 platform?”, the simple answer in short, it doesn’t. The S58 is an all-around powerhouse out of the gate, and with a few simple mods can reach astounding horsepower levels. For instance, the cylinder head on the S58 is entirely different from that of the B58, featuring locations for not one but two high-pressure fuel pumps. Attached to the cylinder head on the exhaust side, BMW went with their tried and tested twin-turbocharged setup with electronic wastegates, improving spool time, lowering the torque curve, and increasing overall performance. The bottom end of both motors share many similarities including displacement, although the S58 has a larger bore and shorter stroke, allowing it to rev out higher than its non-M-motor counterpart.

Straight from the factory, the S58 engine packs a punch with a whopping 480 horsepower. However, the true excitement lies in the engine's ability to handle modifications that can propel it to unimaginable power figures. Unopened, the engine has been known to withstand approximately 900 wheel horsepower and 800 wheel torque, showcasing its already robust foundation laid out by BMW’s lead engineers.

Enthusiasts who are looking to unlock the true potential of the S58 engine turn to a variety of performance upgrades. Notable modifications include larger turbochargers, aftermarket forged pistons, upgraded connecting rods, high tensile strength head studs for increased clamping force, and switching to a fire ring-style head gasket reminiscent of old-school drag racing techniques. Adding in these more robust internals as well as supporting mods is a recipe for S58 success.

Drivetrain Enhancements:

To handle the increased power, a comprehensive approach includes drivetrain upgrades. This involves a built transmission, transfer case, and upgraded driveshafts for X-Drive applications, ensuring that every component can keep up.

Pioneers in Performance: 5150 Autosport

Among the big players in the industry, 5150 Autosport, based in Miami, Florida, stands out as a pioneer in pushing the boundaries of the S58 engine. With their full S58 catalog, enthusiasts have access to a range of performance-enhancing parts designed to extract the most power from their S58 engine. The catalog includes components such as custom-forged pistons, connecting rods, head studs, head gaskets, full engine-building kits, and a large selection of other engine-building components and upgrades available on Turner Motorsport.