Supercharger...

[jonbuoy]

what part of not the best solution but can still work do you not understand?

Go for it - buy one of those fans connect it up with the blowing end ducted into a 250cc metal tank, drill and tap a hole into the tank connect up a pressure guage and let us know the pressure "boost" it gives. You could connect it up to an airmatress or a lilio - about 1PSI max pressure on those, see if you can fill it up if you burst it you might have made a supercharger. A lightly boosted engine is say 7-9 psi about the same pressure as a basket ball.

[imdying]

So you've gone from bullshit Chinese novelty crap to giant sized ducted fan units with an huge appetite for electrical power in an effort to justify what can only be described as an impractical and retarded suggestion. You're a fucked unit

Yes, you can make a supercharger from an electric motor and a compressor. No, none of your ideas are remotely practical.

Finally, given that even an idiot like yourself can admit than even a 2.5kW electric motor isn't going to do shit for a motorcycle engines performance, no matter whether it's driving a fan, compressor, propeller, or Tinkerbells wings... then how is it that you've let your mate get further than a drunken design on the back of a napkin with his super duper 1kW brushless motor on his 'taaaang? Because that's not being a mate... that's just being a cunt... unless you're going to film it for his 21st or something??

[bogan]

Go for it - buy one of those fans connect it up with the blowing end ducted into a 250cc metal tank, drill and tap a hole into the tank connect up a pressure guage and let us know the pressure "boost" it gives. You could connect it up to an airmatress or a lilio - about 1PSI max pressure on those, see if you can fill it up if you burst it you might have made a supercharger. A lightly boosted engine is say 7-9 psi about the same pressure as a basket ball.

a good suggestion with the lilo (don't think we got small enough pressure gauges unless I could be assed making a fluid gauge (which I cannot)), we even have a ducted fan lying round the office at uni, think its only good for thrust in the tens of grams range though, makes a hell of a noise and blows a fuckload of air though!
Think the electric supercharges are only ever gonna be providing fractions of a pound, as too much more and the ecu would need rechiping/remapping. But considering the work some people go to on their intake systems to maintain just neutral pressure after the filter even fractions of a psi may find some use.
Another point is different designs have different pressure limits, positive displacement pumps can hit the highest pressures, then centrfugal turbos etc, thrust prop and ducted fans next probly, then displacment fans used mainly for cooling. Different applications call for different tech.

So you've gone from bullshit Chinese novelty crap to giant sized ducted fan units with an huge appetite for electrical power in an effort to justify what can only be described as an impractical and retarded suggestion. You're a fucked unit

I've gone from a technical discusion to still having a technical discusion, you've gone from the same to mindless insults, who's really the 'fucked unit' here?

[jonbuoy]

When you see how much air an engine swallows at idle its easy to see why these small fans won´t work, this is easier to do on a car - with the engine running at idle try and put the palm of your hand over the air filter inlet and see how much your hand gets sucked onto it (do this at your own risk!) Imagine how much air its sucking at higher revs, the charger has got to keep up with this (and more) to give any "boost" at all.

[bogan]

When you see how much air an engine swallows at idle its easy to see why these small fans won´t work, this is easier to do on a car - with the engine running at idle try and put the palm of your hand over the air filter inlet and see how much your hand gets sucked onto it (do this at your own risk!) Imagine how much air its sucking at higher revs, the charger has got to keep up with this (and more) to give any "boost" at all.

done it on some paddock shitta as a kill switch, the vac is pretty big, but the flow isn't anything too spectacular. Don't have to imagine either, assuming a volumetric efficiency of 80% a 2L engine will draw (2/2*5000*0.8)=4000L or 4 cubic meters per minute at 5000rpm; which is approximately 140cfm. So for the 2.5kW fan I posted before (0.012m2 duct area) the air would need to flow at 5.5m/s or 20kmhr, doesn't sound very fast at all so there may be a hole in my calculations but I can't spot it.

[avgas]

It is impossible to take 1kW from a battery

Very true......which is why he got me to work on a little something for him Hope it didn't blow up on him....but I didn't make any promises.
However I could only guarantee that for a short time - so really his setup would be when you getting off idle. Not a full blow launch and hold. But as we have discussed earlier - volumes are difficult to maintain when the revs get up.
Have no idea where he got the motor from though. Or WTF his air-intake even looks like - so couldn't comment on that.

Slightly side-tracked - but would love to have something like this
http://www.supercars.net/cars/1034.html
Could be a fun little hybrid.

[avgas]

the charger has got to keep up with this (and more) to give any "boost" at all.

I don't imagine these devices are designed to do this. As stated earlier - they are too gutless to maintain whole engine airflow. But are fortunate enough to offer a positive pressure (admittedly small) to a neutral system.
Worth a $5 bolt on fun with something you don't love. But not the $180 being asked.

[pete376403]

If you're going to talk about superchargers... " At maximum pressure, it takes approximately 900 horsepower (670 kW) to drive the supercharger.... Absolute manifold pressure is usually 3.8-4.5 bar (56-66 PSI), but up to 5.0 bar (74 PSI) is possible. The manifold is fitted with a 200 psi burst plate"
and:
"The calculated Power output of these engines is most likely somewhere between 8500 and 10,000 horsepower (approximately 4500-6000 kilowatts)"

http://en.wikipedia.org/wiki/Top_Fuel#Superchargers

[bogan]

The manifold is fitted with a 200 psi burst plate"

lol, what they mean there is they leave one bit of it stock while strengthening the rest! those top fuel engines are fucking amazing though.

[jonbuoy]

http://www.gnttype.org/techarea/turbo/turboflow.html

There is a spreadsheet at the bottom for calculating turbo sizes.

[jonbuoy]

Have you rigged up the fan & discovered the difference between pressure and flow yet?

[bogan]

Have you rigged up the fan & discovered the difference between pressure and flow yet?

nah cbf, rather build motorcycle parts instead, though I do know to get flow you need a pressure differential, albeit a very small one; which was the point I was trying to make anyway.

[Paul in NZ]

I simply cant believe this ever turned into a serious conversation... gleep...

[SMOKEU]

I simply cant believe this ever turned into a serious conversation... gleep...

Anything is possible on KB.

[jonbuoy]

There is one out there that works - looks like a complete pain in the arse for short term gain considering the idea of a supercharger on a stock car is to increase overall drivability. More expensive, heavier and looks harder to install than a belt driven version with less performance so I´m not sure why anyone would want one.


http://www.turbomagazine.com/tech/04...ger/index.html