Electric Supercharging

I read the column in MSL April 2018 issue regarding supercharging pros and cons.

It’s obviously a complex issue and outside of my expertise!

Nevertheless, looking at the current development of electric and hybrid vehicles I wonder if...

How about providing power to the supercharger using an electric motor?

Instead of the impeller relying on the engine speed, the rpm could be set at a fixed rate, which would provide constant pressure from the moment ignition is engaged.

Also, no drag on the engine and once running it can be powered by the alternator.

There are some very clever engineers in the motorcycle industry perhaps you could pass my email onto one of your contacts?

Steven Burton

cars, which have an electric system that is efficient at low engine rpm/low load range to start from zero, and it normally works in a short time.

Electric supercharger is efficient especially at the low end of the rpm range, where the electric charger system can compress air by 3-4kW power, but charger assist time is limited by limited battery size.

For motorcycles, Kawasaki has a very different purpose and approach with using super charger than cars. Therefore the Ninja H2 and H2 SX are using mechanical superchargers. This system can provide superior additional power especially at high engine rpm/high load range.

This makes it possible to run the system for a long time with using its high charged power, specially for sports riding.

The H2 and H2 SX’s mechanical supercharger compress the air and creates 4kW of po ower at below 8000rpm – this is not horsepower, this isi driving power for the sup percharger.

But at the max x load range, this system can offero 20-30kW power to compres ss the air and send a huge volum me of air to the engine to gen nerate superior power an nd an engine feeling that you cannotc get from a normally aspirateda motorcycle engin ne.

From the system weight i ht view point, if we put the 30kW powered electric motor and its power supply (battery) to make the same compression power with the H2’s supercharger, the system would be getting bigger and heavier, making it impractical for a motorcycle.

If the system keeps the charger on, then the battery would be draining, making it impossible to use it for a prolonged period.

OOr you would ld need d an additional big generator to charge the battery, but then the bike would be getting heavier again.

Because of these reasons, Kawasaki didn’t select the electric supercharger, but developed the H2’s mechanical supercharger in-house.