BMW S55B30 engine

Engineers from BMW M GmbH are world-renowned for their commitment to creating truly powerful engines with outstanding performance. Especially for the release of the M3 F80 sedan they have developed a powerful engine S55B30, the real performance of which turned out to be even better than expected. By the way, the same motor was installed on other models, more precisely on:

• a very ambitious M4 F82 coupe;
• the M4 F83 luxury convertible.

The integration was made possible thanks to the very strong performance of the S55B30 powertrain. Its predecessors – the sporty 6-cylinder S54 and 8-cylinder S65 – also performed well both in test runs and in service. However, it was this engine that allowed the engineers from Munich to fully realize their ambitious idea. As a result, the S55B30 produces 431 horsepower, which is an excellent result.

This engine is based on the experience of the N55 turbo-six, which also had outstanding performance. Engineers took about 75% of the old, less powerful model, and added advanced developments. What was the result?

The S55B30 engine turned out to be the smallest (2979 cc) used in the M3, excluding the engine models produced in the distant 90s. While it is worth to focus attention on one more curious feature, namely – forged crankshaft. Together with ultra-light pistons, it allows to achieve much better dynamics, and by this indicator significantly overtakes even 3-liter units.

What’s amazing is that with a 25% reduction in engine displacement and the absence of two additional cylinders, engineers from BMW M GmbH managed to achieve high performance, or more precisely, a 10 horsepower increase. The secret of success is quite simple and lies in the use of a patented induction process that allows for increased combustion efficiency.

S55B30 engine specifications

Advantages

The cylinder block has been significantly modified. For its production it was decided to use aluminum alloy AlSi 7Cu0.5Mg. In addition, the engineers also changed the cylinder head, which makes it different from the N55 model.

An important benefit that motorists need to be aware of is the reduction in fuel consumption by as much as 28% with a 37% increase in torque. Many rave reviews testify to this. It’s all about the application of technology:

• BMW Efficient Dynamics;
• M Twin Power.

The latest development deserves special attention. This technology is a combination of:

• two turbochargers;
• high-precision fuel injection systems;
• VALVETRONIC (third generation).

The variable valve timing system (VALVETRONIC) plays an important role. This ensures that the valve lift is precisely adjusted. As a result, the S55B30 engine produces power smoothly, reducing emissions and consuming considerably less fuel. Hence the savings.

Now back to the forged crankshaft. Made of 42CrMoS4 Mod alloy, it is perfectly adapted to the engine’s increased power as well as its high rpm.

Disadvantages

It goes without saying that such high performance does not go without a trace. The engine gets warm, and very warm, and under extreme loads on the track can lead to serious breakdowns. To avoid such incidents, engineers installed a special cooling system. Now the S55B30 has two radiators: a main radiator and an additional one.

Another important note: the engine is very demanding to the type of fuel. In order for it to please the owner of the “Emka” with excellent dynamics, it is necessary to pour only A98, and without compromise. Even professional chip-tuning can not correct the situation, because S55B30 responds to it with unstable piston stroke.

The use of fuel with a low octane rating causes detonation during combustion. As a consequence, this significantly reduces the operating life of the engine. Add to this the possibility of severe overheating and you have a high risk of breakdowns. The solution: monitor the quality of fuel and refuel only at proven gas stations where fuel is guaranteed not to be diluted.

There is another problem with the S55B30 swap, and that is loss of compression. Chronic overheating at high speeds entails the rupture of gaskets, and, even worse, violation of the integrity of the cylinder block. To prevent the occurrence of serious engine failures, you should regularly undergo a technical inspection (every 40-50 thousand kilometers of travel) and, if necessary, replace components.

How did it affect the speed

This is an important question for fans of BMW’s M-series cars. The S55B30 engine really helped to make the cars quicker, and the following data is enough to prove it:

• The previous generation motors reached maximum power at 8,300 rpm;
• S55B30 this figure is only 7,500 rpm.

If accurate data is required, it is worth comparing this engine with the famous 4.4 liter V8, which actively showed itself on the M6 and M5 models. The S55B30 engine develops 16 hp/liter more than its predecessor, which is an excellent indicator.

Are there modifications

The engine is often compared to the C55 model. It has been modified and finalized by engineers. A water injection system was installed, which solved 2 problems at once:

• The engine output has been significantly increased, which is perfectly reflected in the increase in dynamics;
• the service life has also increased, which indicates a decrease in wear of the main mechanical components.

Is it possible to “overclock” it?

This is an important question for adherents of chip tuning, who want, for example, to make n55b30 conversion s55b30. Munich division is known for deliberately underestimating the performance of new engines. Resorting to a home-made method, you can bypass the factory protection, adding another 10-15 “horses” to the power indicator, but here the question arises: is it worth it?

Considering how demanding and capricious the S55B30 swap is in operation and how much it needs maintenance, you shouldn’t take any chances with chip tuning. If you are a professional racer and you need to improve dynamics and increase speed, then take into account another factor. The S55B30 is very lightweight, with a weight of 205 kilograms, made possible by a lightweight body.

Another option is a swap. An example is the replacement of a turbine or other component. This opens up the possibility for additional modifications and, as a result, an increase in speed.

Conclusion

The arrival of the S55B30 engine is the best thing to happen to the M Series in recent times. This is true of the M3 F80 sedan, which has only benefited from the installation of the new three-liter engine. Reliability with competent care is the hallmark. The motor is suitable for all sorts of driving styles, and shows itself well both in city conditions and on race tracks, giving the driver incomparable pleasure from driving. This is what makes it so popular.

This engine is installed on the following models:

BMW M3 (F80)

BMW M4 (F82)

BMW M4 (F83)