Originally posted by Josch:
I have a fairly decent grasp on the laws of physics, and all I can see from all these posts is that Rara has a pretty good grasp too.


Maybe so, but in this case, nobody has come up with a coherent way to back up this criticism of "you've disregarded flow".

Originally posted by Josch:
You maybe need to study this stuff better before you waste alot of money on your prototypes.

First of all, a starter motor doesn't come anywhere near even close to 10 hp.


The larger ones do.

Originally posted by Josch:
The only reason it can turn an engine over is because it is gear reducted (ie. big flywheel vs. tiny starter gear).


That's torque, not horsepower. Gearing doesn't change horsepower demand.

Originally posted by Josch:
If you were to gear it the other way to try and turn a compressor impeller the speed necessary to feed an engine running at 5000rpms with 4psi say, I don't even think the starter would barely turn over (the vacuum from the engine's intake across the impeller would probably help the starter turn a little). I don't even think you could get .001 psi at 5000rpm with a typical starter motor off a car.


The e-RAM product delivers about .5 PSI with a motor one tenth the size and current draw of a starter motor -- it's small enough to hide in your hand -- and that's with a poor kind of compressor. That would not be possible if this speculation of yours were valid. And also, it's in line with what the flow times backpressure calculation predicts.

Since I have measured this myself and know it's true, this speculative naysaying of yours goes right out the window. All you have to offer is guesses.

Originally posted by Josch:
Here, read this:
[....]
and
http://www.electricsupercharger.com (haha)


The ebay stuff is scams using tiny weak motors. The latter product was dynoed with an authentic 9 HP gain by Brad Noon, one of the most respected CEGers. That's the one I measured the boost on myself.

Originally posted by Josch:
Why not just use a pulley/belt and a shaft (ie. Vortec) to get the power directly and avoid all the heat losses from electron movement (not to mention the weight from motors and batteries),


Because belt-driven superchargers, both centrifugal and positive-displacement, put a demand on the driveshaft that is not moderated in proportion to the need for power, and that demand is greatest when you're working the engine the hardest. An electric blower, on the other hand, draws power from the driveshaft at a later time, when the engine is not under a high load.

Originally posted by Josch:
or use the 'free' exhaust gases (heat energy) that the motor just throws away anyways and convert that to usable energy (ie. conventional methods)??


Well ideally, that's what you'd do even with an electrical system. I think that hybrid-electric cars are going to be pretty much the norm by 2010 or so, and when they are, it will make a lot of sense for the makers to put the generator on an exhaust turbine instead of on the drive shaft. It could boost mileage significantly, and there will be plenty of pressure to boost mileage. I am not using exhaust power for the simple reason that I'm doing this cheap. If I was going all-out, of course I would use exhaust power.

Originally posted by Josch:
By the way, I had your same idea when I was like 18-19 years old and it DOES sure sound like a good idea on paper, but it just can't work with today's technology. Wouldn't you just rather work extra hard for a summer and then just buy the complete turbo kit?


Where's the fun in that? I'm not a racer, I don't spend my weekends at the track trying to shave tenths off my ET... if I'm going to invest in a big engine project, I'm going to do it because it's interesting and original. If I fail, I'm out a smallish amount of money and some absorbing hobby time, and if I succeed, I open a pathway that people didn't have available before. That means more to me than just having a faster car. If I just want a faster car I'll buy one.