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On 31 Aug 2004 at 23:42, John Jaranson wrote: > > I can't help wondering how much loss we should expect in the drive > > train. > The number I kept hearing at the car show was 20%. Rule of thumb was a > 20% loss from the flywheel to the road with a manual transmission. > Don't know about an automatic. I will ask a few of my powertrain > buddy's at Ford this question tomorrow. 20% seems consistent with > numbers I got for Sophy. You may be right, but that sure sounds high to me. I just keep thinking about all the energy that this would mean gets dissipated in the transmission (I realize that not ALL of the energy is wasted in the transmission, but I assume that that's were the majority would go) and how hot that would have to get. One HP is 600-700 watts. If you don't think that sounds like a lot, wrap your hand around a 50 W light bulb and then turn it on, and see how long you can leave it there. Of course the transmission has a lot more surface area, but we're talking about dissipating ~100 times as much power. And our hands are liquid-cooled. In normal crusing there would be much less power used, and much less loss, but how about those climbs up the mountains on the way to Parma? I wish we had thought to feel the transmissions then. Our output was maxed and our speed (cooling) was minimized. The trannys should have been REALLY hot. I'll ask my drivetrain friend here, too. -- Jim Adney jadney@vwtype3.org Madison, WI 53711-3054 USA ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ List info at http://www.vwtype3.org/list | mailto:gregm@vwtype3.org ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~ Shameless link for search engines: http://listarchive.type3.org ~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~