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Details of Yamaha’s 3-cylinder turbocharged prototype


As we said recently, the world is moving towards superchargers. Strict environmental standards lead to the need to burn fuel as efficiently as possible, and the catalyst here is an expensive half-measure, essentially meaning that the manufacturer has failed to ensure the efficient operation of the engine. Therefore, equipping a high-performance engine with a forced supply of the required amount of air is a task that inevitably faces any manufacturer.

So Yamaha, faced with the need to comply with current (and most importantly, future) environmental standards, is developing a supercharging engine – at least, as follows from new patent applications, which reveal the details of the three-cylinder turbocharged prototype.

The prototype, which has undergone a series of tests this year, produces 180hp at 8500rpm and an impressive 176Nm of torque ranging from 3000rpm to 7000rpm, and its exhaust is 30% cleaner than a naturally aspirated engine of similar power. The bike itself is a naked MT-10 style bike.

Yes, it is possible to remove such a peak power from such an engine without a supercharger, but for this it must be very strongly unwound, and it will not be possible to obtain similar torque figures. High revs on a naturally aspirated engine, in turn, are extremely unfriendly and may become an obstacle to Euro 5 homologation, and with the upcoming Euro 6 it will be even more difficult to produce squealing high-revving engines. The whole problem is precisely in the purging: the engine does not have time to exhale a large volume of exhaust gases and inhale fresh air in a short time, so it is necessary to implement overlapping valve phases, in which the intake valves open even before the exhaust valves are closed. Obviously, part of the mixture is then released into the outlet.

There are several potential solutions: variable valve phases, direct injection, but superchargers (turbines or superchargers) are the best way to take maximum power without spinning the engine to the highest rpm. However, this solution is not without complications: compressing, the air heats up, therefore, in addition to the supercharger, an intercooler must be installed at the inlet, and there is not too much extra space on the motorcycle. Not surprisingly, some of Yamaha’s new patents are centered around solving this problem.

One variation found by Yamaha and disclosed in the patent application is the unusual arrangement of the radiator and fans. The radiator has been moved from its traditional location to the bottom of the engine, making it possible to replace it with a supercharger with an intercooler.

The Yamaha patent also describes an unusual curved radiator shape that allows the front wheel to turn freely without touching it, and to install cooling fans on the side edges. At the same time, the structure can fit quite tightly to the engine, have a large cooling area and not be too bulky.

The company also submitted a compact intake manifold in the application with one electronically controlled valve that regulates the supply of compressed air to the engine.

Exhaust of a turbocharged Yamaha motorcycle

Another Yamaha claim concerns the exhaust of a turbocharged motorcycle, which differs significantly from the usual one.

Installing the turbine directly in front of the cylinder bank means that the 3-1 outlet pipes will be very short, converging right after exiting the head to supply the exhaust to the turbine. After the energy of the expanding exhaust gases has been partially used to rotate the supercharger, they leave the turbine through a single pipe of noticeable width. The Yamaha patent explains that several catalytic converters are installed in this wide section of the exhaust duct, one immediately after the turbine, and another in the horizontal section of the exhaust below the engine. And finally, under the pendulum axis there is a muffler, the short exit section of which looks to the right. Surprisingly, the exhaust of the turbocharged engine from the Yamaha turned out to be even more compact than the aspirated one. – mainly due to the lack of the need to select the length to optimize the flow of exhaust gases.

Developments Yamaha

Apparently, Yamaha is rolling around its developments on an already created and assembled motorcycle with its own interesting style. But we still do not know whether he will get into the series, and if so, when. Previous patent applications from Yamaha included a slope tricycle with superbike capabilities, an all-wheel drive version of the YZF-R1, but despite impressive test results, none of these prototypes went into production.

The turbocharged motorcycle from Yamaha looks promising nonetheless, as rivals in the Japanese Big Four are also working on powerful supercharged motorcycles. We can only hope that the next eco-norms will not bury large gasoline engines, and the top models will not have to be made on an electric drive.

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