have We all gone mad? The combustion engine is not dead. To those who see with more optimism the road to electric mobility, or hydrogen, still recognize that heat engines will continue to accompany us, and to dominate the sales world for many years. What nobody can deny is that the future of the combustion engine has to be understood in key downsizing, in engines with little displacement, and turbo, get a high efficiency with a consumption content, which is ultimately the goal. How and to what extent they can be tightened for an engine to deliver lots of power with the minimum displacement? The new jewel of the BMW will be a diesel with six cylinders in line and nothing more and nothing less than four turbos. Like what you hear. Long time BMW has been working on a diesel engine is very powerful with these features. But as we will see below, not everything is a matter of power.
why four turbos? The ultimate goal of the turbo is not other that the use of the kinetic energy of the exhaust gases to compress the gases in the intake and greater efficiency. The problem in the choice of a turbo is that usually we have to choose between a turbo that requires a greater pressure of the exhaust gases to work, and get a higher return, or opt for a turbo, low inertia, with a turbine that turn with a pressure of the exhaust gas lower, but in exchange we may not be able to extract a yield as high of an engine.
There are mid-term elections, as the turbos variable geometry, but ultimately the solution that remains for us is to increase the number of turbos, of different nature, and in an arrangement in accordance with the architecture of the engine with which we are working. And that is the reason why BMW is interested in this diesel engine four turbos.
What do you look for BMW with a diesel of four turbos?
The ultimate goal is to achieve the performance of an engine of eight cylinders in a v with a block of six cylinders in line. According to Bimmerpost, BMW would have given more details of this engine at the Vienna Motor Symposium in these days, speaking of figures around the 400 HP between 4,000 and 4,400 rpm and a maximum torque of 760 Nm from 2,000 and 3,000 rpm. We would talk about a diesel that I could launch from standstill to a vehicle equipase – that precisely would not be the smallest – on a 0 to 100 km/h in less than 5 seconds. It is likely that this engine could even work with a higher torque, but at the end should conform to the technical requirements of automatic switching, source ZF, with which he would work.
But we insist. it is Not only about providing benefits, but above all to achieve an engine with the best touch possible, with a low delay, and with a delivery linear that you get your landlord does not miss the diesel engines of eight cylinders.
The solution chosen by Audi, which we already presented it with the Audi SQ7 TDI 435 HP, went through the use of two turbos and an electric compressor, while maintaining a diesel engine of eight cylinders. The electric compressor is primarily responsible for the supercharging of the engine before the pressure of the exhaust gases is sufficiently high so that the turbo starts to work.
BMW, in contrast, bet on two turbines of low inertia, small, and capable of spinning very fast at low pressures of the exhaust gases, as the engine has three turbos used up to now for the 50d three turbo. The novelty would be in that, instead of using a turbine of larger size to cover the top of the rev counter, BMW would have chosen a system of double-turbine, with which they would be able to extract an even higher throughput of the block-diesel six-cylinder and 3.0-litre, the already-obtained by the engine has three turbos that for years have used models such as the BMW X5 M50d.
Note: the pictures that illustrate this entry to correspond with the engine 3.0 diesel six-cylinder and three turbos from BMW.