In just a few months, the new BMW M3 Sedan and BMW M4 Coupe will come to market. The two brothers, along with the M4 Convertible, will mark a new era for the most popular M family ever built in Garching.
BMW has reverted to an inline six cylinder for the new M3 and M4. But unlike the S54 in the E46 M3, the new S55 is turbocharged. Based on the N55 six cylinder, the S55 utilizes VANOS and Valvetronic as well as gasoline direct injection in the cylinder heads. But unlike the N55′s twin-scroll single turbocharger, the S55 utilizes two turbochargers, one turbo per three cylinders. Given all of the heat the engine is capable of producing, BMW has taken great care in ensuring that it is properly controlled, especially knowing that the M3/M4s will see a lot of track time.
The S55 is set to deliver 431 HP and 406 lb-ft of torque. To ensure that nothing untoward happens on the bottom end the S55 employs a forged steel crankshaft. The torque developed by the S55 is fully available from 1,850 to 5,500 RPM which leads one to believe that the turbos selected for use on the S55 are slightly larger than the ones employed on the N54 motor of yore. Two tidbits worth considering are the huge increase in torque over the outgoing V8 and the approximately 25% increase in fuel economy of the S55 over the V8.
Tuned For The Race Track
The M3/M4 utilize BMW’s proven double pivot strut front suspension and multi-link rear suspension. The front and rear suspensions utilize M specific aluminum components which are light weight and biased towards stiffness. The front suspension has additional stiffening in the form a CFRP strut brace, aluminum stiffening plate, and additional connection points between the sub-frame and the chassis. The downside of the additional stiffening may be additional harshness but the responsiveness gained is beneficial. The suspension features the M Adaptive suspension settings of Comfort, Sport, and Sport +.
The M3/M4 exhibit a degree of technological capability/creativity that were unimaginable when the original M3 was conceived.
Let’s see it in action before the upcoming press drives: