Recently this email came in.
Great column in the October '08 issue. It's disturbing to see and hear some of the huxters playing on the fears of people who may not know any better, or not know where to turn to get a straight answer on the "technology" these guys promote. I definitely commend you on that.
My question is around your joking comment about installing the HAFC "...
after my Tornado and electric turbocharger come in the mail."
Wasn't it just last summer that I saw both SCC and your sister publication Super Street promote E-Ram's electric supercharger in you magazine's sections devoted to new products in the marketplace? Is there a decided difference between the E-Ram supercharger and all the electric turbos and blowers we see on eBay? I've always assumed that none of that stuff is for real.
Thanks for reading this, and thanks again for putting out a great magazine.
While I can't speak for the guys over at Super Street, SCC's new products section typically is picked from products that editors approve of, or what advertisers push. In the case of the E- Ram, if we did in case run that, it was advertiser pushed.
E-rams, electric turbo chargers or whatever you want to call them are bound by the same thermodynamic laws the HAFC is. Basically, you can't get more energy out of something than you put in, and that any energy exchange or conversion process has irreversible losses like heat.
So say it takes 5hp to drive your electric turbocharger/compressor. Thats 5hp thats taken from what your engine outputs, probably more since there are losses in the belts that drive the alternator, electrical wiring and the compressor electric motor itself. The reason that a exhaust driven turbocharger works is that its taking free energy that would otherwise be thrown away in the exhaust and turning the compressor.
The only time you can make more power than you take out from the engine is in the case of a supercharger. Although mechanical power is consumed from the engine and drive belts in compressing the air, the sum power output is still more than what the compressor is eating but because you're throwing in a lot more fuel now that there is boost. The net power gain from supercharging is from the chemical energy stored in the fuel.
Even if the E-ram is able to generate one or two psi of boost and you could benifit from the additional air in the intake, the fact that its electrically driven means that the system already incures a tremendous amount of thermodynamic loss through the electrical systems and the compressor itself. I have a hard time imagining that someone designed a compressor to operate at peak efficiency pumping the miniscule amount of air a electric motor of that size can.