I like the idea of forced induction to increase the power of engines. Turbos and superchargers force air at high pressure into engines, as opposed to using the partial vacuum created by the falling pistons and atmospheric pressure to fill the cylinders. Add the proper amount of fuel, and a smaller engine can run like a much larger one, with the added bonus of being more efficient and lighter.

Turbos create boost by using exhaust gases to spin a fan-like impeller. This impeller in turn spins a second impeller that compresses the intake air. Turbos are able to make impressive levels of power, but suffer from lag, and heat/oiling issues arise as you're using HOT exhaust. The biggest issue, though, is that a turbo is a turbine, which is only efficient at ridiculous RPMs, and has a wind up/wind down phase, seen as lag at low rpm, then power grows exponentially to engine speed and you need to blow-off the excess pressure at high boost. Best left to high spinning engines, turbos make their best power higher in the rpm range.


Superchargers compress air by using a belt/pulley system attached to the spinning engine itself. They "steal" energy to drive themselves, but are tied to the engine, and linearly produce boost as the engine speeds up. This produces a good, low end torque bonus, but the peak power is often not as impressive, as these is a maximum speed to blowers, because the rotors need time to "bite and compress" the incoming air. As rotor speeds approach their ceiling, efficiency drops off as heat increases and laminar flow decomposes.

So, you can choose a ripper engine that makes crazy HP but has a vicious exponetial dyno chart(turbo), or a torquey, powerful engine that "signs off" at higher rpm's(supercharger).

Until now.

Atonov has developped a two-speed transmission for superchargers, allowing two peaks in hp by slowing the rotors at high engine speeds.

Not much info yet, here's the site that gives a little tease.

I'd like to see this finally evolve into a variable pulley system, much like a snowmobile uses, varying the input and output shaft rpms to keep the charger at it's most efficient rpm, but belt slippage would be the issue. Maybe a Subaru Justy style CVT, but packaging it could become an issue.

These are good times to be a HP junkie... the oil prices and the switch to four-stroke are forcing huge gains in HP/L of displacement. In the 90's 100hp/1000cc of displacement was a "powerful" motorcycle engine. Now, 1000cc bikes are putting out 180HP, with no signs of slowing. MotoGP bikes are making 220-260 HP with 998cc's.