Drumcharging, according to exclusive rights holder AlterEgo Hardware, is the future of supercharging for motorcycles. And if the Italian-based firm has its way, it’s the future of small cars, tractors and stationary engines, too. Because in these days of increasingly stifled emissions which in turn are strangling the capability of engine output, manufacturers are being forced to find more grunt more efficiently.
If the motorcycle industry looks to the car world, it seems forced induction is where it’s at. But superchargers and turbochargers are not only bulky items to squeeze into compact motorcycle-sized architecture, they also add significant and unwanted cost.
AlterEgo Hardware is all about smart, simple and low-cost engineering and it says its drumcharger may just be the answer. While the drumcharger only offers a fraction of the boost that a conventional supercharger or turbocharger would, it can be produced at a fraction of the price.
How does it work?
The drumcharger uses the engine’s exhaust gases to push fresh air into the intake. The unit consists of a plastic chamber that is separated into two compartments by a carbon fibre membrane and weighs just one kilogram. The hot chamber harnesses the exhaust pressure to push on the membrane as the gases exit the engine, which compresses the cold chamber, forcing the air inside into the airbox. The cleverness lies in the simple fact that it’s inherently synchronised with the engine and its actuation is purely mechanical, negating the need for electronic management.
How much does it help?
According to AlterEgo’s bench tests, the drumcharger increases torque by up to 15 per cent, improves engine efficiency by up to 20 per cent and fuel economy is improved by up to 30 per cent. The drumcharger was officially unveiled at EICMA in Milan and the firm is knocking on manufacturers’ roller doors as you read this, saying that it can improve the quality of combustion to the point of being a bolt-on retrofit solution to complying with Euro 4 and even Euro 5 emission regulations.
Which bikes can use it?
Because of its mechanical nature, the drumcharger is best suited to small capacity motorcycles (up to 400cc) and with no more than two cylinders. Right now, there’s the option between a single or a dual version and, depending on the motorcycle, the dual might be two drum chargers mounted side-by-side or ducted so that two hot chambers are pumping into a single cold chamber. It needs to be kept quite cool, too, so the drumcharger needs to be mounted at least 60cm from the head of the engine to create a so-called thermal barrier.
By Kellie Buckley
