Whats the general consensus on electric superchargers?,

from what I have seen, it does exactly the same as a proper turbo, apart from the fact that it's electrically driven, rather than being driven by exhaust gas,

Providing that the ECU can adjust the fuel enough to meet the increased airflow do you see similar results or is it just another con like the +1000BHP resitor chips:D

From what I understand they cant actually supply enough air to warrant it, and the electrical load from such a device would be astronomical anyhow.

You can achieve better results than old-skool turbo's because you can spin the supercharger at whatever speed you like providing there's enough air (rather than waiting for a specific volume of exhaust gases so you can have minimal lag. However, the energy to drive the supercharger has to come from somewhere so any gains will be offset by how much is required to spin it......

I think with the introduction of twin scroll and variable vane turbo's lag is much less of an issue now and the energy to drive them is still "free".....

Chris

These were a 1990 phenomenon that work pretty well. You need to run an uprated alternator to supply enough current to drive them. IIRC someone had one on a Honda VTEC unit fitted in an Elise somewhere locally.

They are generally less efficient than superchargers when on boost, but more efficient off boost as the load can be adjusted independently of crank speed.

Chris

have a look at this eBay.co.uk: Pit Bike Xsport Thumpstar 110cc - 125cc Turbo Kit (item 170118906816 end time 11-Jun-07 11:37:46 BST) a freind of mine put one on his pit bike and it did make quite a lot of diferance (lol boys and toys)

i read about a test in one of the tuning mags ,where they put one on a standard mr2,dyno standard then with the electric supercharger fitted,it actually produced less power with the thing on,they did say it may be a different story on a different application,but who knows.The difference was only about1.5bhp btw.

There are two types of electric supercharger. One type is the small low voltage axial fan type that will produce very little gain at low revs and lose power higher up. These are cheap and nasty gimmick products. The second type are generally high speed axial blowers driven by very powerful motors (up to 5Kw) that will produce proper results.

The main problem with electric supercharging is efficiency. With a belt driven charger, the losses are purely mechanical. With an electrically driven charger, you get mechanical losses between pulley and alternator, generation losses, transmission losses, electric motor losses, all added to the existing mechanical inefficiencies.

Smart turbo charging solutions have rendered the electric supercharger redundant in the automotive sector.

Overall, fitting forced induction to an N/A motor is easier when using s-chargers due to the lower likelyhood of trashing the internals and popping the head gasket.

But, as above, the energy required to drive the thing and produce a greater level of air than what is available at atmospheric pressures would be immense. Even belt driven ones drain a lot of HP from an engine before they become of benefit once boosting.

A turbo's energy source is not 100& free......the resistance to the exhaust gases produces a little more back pressure than normal meaning the engine has to work harder on the exhaust stroke but the losses are far less than on belt driven technologies. Either way, turbocharging places a greater strain on the internals due to the lag and sudden rise in power and induction pressure. It requires a much stronger engine and fiddling with the compression ratio when retrofitted to an N/A engine.

Con, unless you're getting an electric motor with a several Hp rating on it, and a belt-driven supercharger to go with it.

The

The tricky part is the control of the system. If linked to the ECU, to match demand and fuelling properly, then gains coiuld be good, without the lag of a turbo, and backed off when not required, to reduce the efficiency loss you get with a supercharger. I saw a concept (Honda IIRC), which used free power turbines (basically the exhaust half of a turbocharger) to claw back some of the power used by the electric blower. The overall plan was a sort of part time charger. As mentioned above, though, the power required is substantial.

Phil

Theres a video of someone dynoing a car with and without a leaf blower attached to the intake on you tube somewhere.

It proves the theory is sound, but unfortunatley it's hardly practical!

edit:

found it - Video - Leaf Blower Bolt on Dyno pull