s4oopie wrote
as with the electric super charger it needs an electric current to work and the amount of amps its gonna take to get any where near as much boost will as some one pointed out would be counter acted by the alternator creating drag lol
Not entirely true. Any form of forced induction takes energy from the motor to run it, superchargers by direct drive from the crankshaft, turbochargers from the exhaust (energy that is otherwise largely wasted, but a turbo will put backpressure on the exhaust) and the electric fan in the ebay advert takes 800 watts (65 amps or so) to generate its one or two PSI boost.
That's the real reason it can't be used full-time. Even the diesel Leons only have 90 amp alternators, and most others have 55, 60 or 70 amp generators. And they aren't intended to be run at high currents for long periods. If you ran the electric supercharger full-time, you'd flatten your battery.
Transmission of power by electricity is quite common - diesel-electric railway locomotives, ships and submarines for instance, installations where installed weight doesn't matter too much (low resistance to motion of the vehicle, and most of the time spent cruising at one speed). The weight penalty of an electric supercharger is high (bigger generator plus fan motor) - and this would eat into the power gain.
Even very efficient supercharger designs, twin-screw or centrifugal fan, consume 5-10% of the engine power in operation, but can boost the engine's output by up to 50%, in effect by increasing the compression ratio.
Lets say we want to boost an 80HP base design up to 120HP, and we have a good compressor, it's still going to need 4HP to drive it. Thats 3 kilowatts, or 250 amps at 12 volts.
Oh, and that efficient compressor will not be an axial fan, either.
as with the electric super charger it needs an electric current to work and the amount of amps its gonna take to get any where near as much boost will as some one pointed out would be counter acted by the alternator creating drag lol
Not entirely true. Any form of forced induction takes energy from the motor to run it, superchargers by direct drive from the crankshaft, turbochargers from the exhaust (energy that is otherwise largely wasted, but a turbo will put backpressure on the exhaust) and the electric fan in the ebay advert takes 800 watts (65 amps or so) to generate its one or two PSI boost.
That's the real reason it can't be used full-time. Even the diesel Leons only have 90 amp alternators, and most others have 55, 60 or 70 amp generators. And they aren't intended to be run at high currents for long periods. If you ran the electric supercharger full-time, you'd flatten your battery.
Transmission of power by electricity is quite common - diesel-electric railway locomotives, ships and submarines for instance, installations where installed weight doesn't matter too much (low resistance to motion of the vehicle, and most of the time spent cruising at one speed). The weight penalty of an electric supercharger is high (bigger generator plus fan motor) - and this would eat into the power gain.
Even very efficient supercharger designs, twin-screw or centrifugal fan, consume 5-10% of the engine power in operation, but can boost the engine's output by up to 50%, in effect by increasing the compression ratio.
Lets say we want to boost an 80HP base design up to 120HP, and we have a good compressor, it's still going to need 4HP to drive it. Thats 3 kilowatts, or 250 amps at 12 volts.
Oh, and that efficient compressor will not be an axial fan, either.
