[YesAuto Engine Technology] The BMW M2 was officially released at the end of October last year. BMW's compact coupe attracted the attention of many BMW fans as soon as it was released. Compared with the BMW 2 Series M235i (F22), the BMW M2 (F87) has been retuned to 3.0T N55B30 engine (hereinafter referred to as “N55B30”). And driving pleasure is even more advantageous than M3/M4. At this year's Geneva Motor Show, BMW exhibited the N55B30 on the M2. Let's take a look at what features it has.

BMW M2 and BMW 2 Series M235i are models that focus on sports performance. The power output parameters of the N55B30 on them are much stronger than those of the same model used on the BMW 5 Series 535Li. The fuel injectors, valve lift control system, pistons and crankshaft bushes on the BMW M2 N55B30 are all directly used by BMW M4 S55B30 components to ensure the durability and stability of the engine at full load output.

Comparison of N55B30 engine parameters on three BMW models
Model BMW M2 BMW 2 Series M235i BMW 5 Series 535Li
Displacement 2979mL
Intake form Turbocharged
Bore 84mm
stroke 89.6mm
Maximum horsepower 370 horsepower/6500rpm 320 horsepower/5800-6000rpm 306 horsepower/5800-6000rpm
Maximum torque 465 N·m/1400-5560rpm 450 N·m/1300-4500rpm 400 N·m/1200-5000rpm

Why does the BMW M2 not use the S55B30 on the BMW M3/M4, nor the latest BMW B58B30? I think this has a certain relationship with model positioning and engine modification potential.

Comparison of engine parameters of N55B30/S55B30/B58B30
Model BMW M2 BMW M3 BMW 7 Series 740Li
engine model N55B30 S55B30 B58B30
Displacement 2979mL 2979mL 2998mL
Intake form Turbocharged
Bore 84mm 82mm
stroke 89.6mm 94.6mm
Maximum horsepower 370 horsepower/6500rpm 431 horsepower/5500-7300rpm 326 horsepower/5200-6500rpm
Maximum torque 465 N·m/1400-5560rpm 550 N·m/1850-5550rpm 450 N·m/1380rpm

The exhaust gas of cylinders 1-3 on the N54B30 drives one turbine, and the exhaust gas of cylinders 4-6 drives another turbine. After the N55B30 abandons the twin-turbo system, the exhaust gas of cylinders 1-3 is introduced into one of the turbine's scrolls, and the exhaust gas of cylinders 4-6 is introduced into the other scroll. By using twin-scroll turbines to improve the turbocharging efficiency of the engine at low speeds, the N55B30 on the BMW M2 can output a peak torque of 465 Nm at 1400rpm.

The intake valve lift adjustment system can replace the role of the throttle, adjust the engine's intake volume according to the engine load, thereby reducing fuel consumption and achieving the purpose of improving engine fuel economy. The car's official fuel consumption per 100 kilometers is 8.5L. For a coupe, its performance is quite satisfactory.

BMW began to use electronic water pumps on a large scale in the N52 series engines. Although the cost of the electronic water pump is relatively high, the many benefits it brings allow BMW to continue to use this configuration on the N54 and N55 engines after the N52. BMW’s latest 3.0T B58 inline 6-cylinder engine uses a mechanical water pump driven by a belt, with an electronically controlled coolant flow control valve to achieve engine thermal management; at the same time, a small electric turbocharger is equipped The water pump realizes the cooling of the turbine when the flame is off. Is this technological progress or technological retrogression? I think BMW has used new technology to reduce the cost of vehicle manufacturing without reducing the level of engine thermal management. This is the result of a balance between cost and benefit.

The electric control device can quickly and accurately control the opening of the exhaust bypass valve, and realize the rapid and precise adjustment of the boost pressure, making the turbocharging system more efficient and more responsive. We can see the same device on many newly introduced engines.

Edit summary:

The 3.0T N55B30 engine on the BMW M2 looks different from the 3.0T N55B30 engine on the BMW 2 Series M235i. However, the improvement of power parameters will inevitably require certain strengthening and lightening of the piston, crankshaft, connecting rod and other components inside the engine. The re-adjustment of the engine management system is also a key factor in squeezing the power output of the engine. In some details, the N55B30 engine on the BMW M2 has also been improved compared to the earlier N55B30 engine, such as the exhaust bypass valve with an electric control device. BMW M2 as a performance coupe, engine power performance is important, but fuel economy has not been neglected. The engine on it is equipped with engine intake and exhaust variable valve timing system, intake valve lift control system, electronic water pump and other technologies. To a certain extent, it has achieved a balance between power performance and fuel economy, and has not made fuel consumption a BMW. The burden of M2 owners. (Photo/Text/Car House Chang Qinglin Photo/Car House Xia Zhimeng)