Electrical Supercharger

[Jeremy Edmondson]

Watson, Bill wrote:
> 
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> REPLY FROM: Watson, Bill
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> Seth Allen wrote;
> 
> .....if it take 5 hp to compress the air divided by the efficiency
> (60%) that means 6.3 hp, or 4750 watts, or about 400 amperes at 12
> volts, or about what it trakes to crank the car.  Maybe with two or
> three
> batteries and a more efficient centrifugal blower (80%ish)?  I may be
> off
> onthe hp requirement, but I bet that I am not off by an order of
> magnitude.  You would need a lot of fets in parallel to drive that
> motor,
> or run up the voltage and take a loss there.
> 
> Maybe my math is wrong, but there must be a reason whay it hasn't been
> done.
> 
> Seth
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> 
> Seth, I agree, (except 400 Amps is about TWICE what it takes to crank
> the
> car) but I think you ARE off by an order of magnitude.  D'Oh!  Its
> more like 30-70 HP of compressed air, depending on mass flow rate and
> boost.
> The power requirement is Huge!
> 
> I'll dig up the compressor HP on a Turbo for a Buick Grand National
> later
> today (35 lb/min at 15 psi), but I think it was in the vicinity of 50
> HP.
> 
> Bill

>From quick calulations for a 350ci, 5000rpm and 10psi boost the power requirement to 
run a blower assuming 80% efficency is 45hp.  Using a 12v motor 2600amps is needed.  
How big is you alternator?