I'm not going to try and argue the point.,well, maybe a little. It's beyond my knowledge base and I'm not about to pretend otherwise. All I know is if you take a tablesaw and run green wood thru it the thing slows down and the motor gets hot. Shortening it's life and since I don't have an AMP meter on my tablesaw I don't know what the useage of electrical amps does, but if extra heat is generated, then I assume elctricity is being wasted. Leading me to believe that even if energy usage was the same, less heat generated would lead to longer life of components. On the flip side if you get the motor to run 3,000 rpm freely it would be better then spinning the motor at 5,000 rpm freely. Or would it??? I did see the XJ's Motor is rated for 5,000 rpm and he is looking at installing 4:56 gears! He also said he does not use 4&5 gears in the manual trans. It would beinteresting to see if he accomplishes anything by instaling 4:56 gears! Since he now runs in third at speed what difference would 4:56 gears really do? I would expect he will simply switch the gears commonly used in the transmission! The high pinion in the rear of an American body sounds interesting, But is it really needed? You could build any one of a number of high pinion axles for this purpose. Reverse cut gears could even put the motor facing rearward and then the battery packs could be placed in the rear floor area and under the hood till everything balanced out nuetral. I expect that a single geared electric car would not have the versatility of a multi geared transmission equipped vehicle. Which leads into the next thought. Larger motor, with a hunt or switch reducing voltage at a set point or speed to increase range? They routinely run the motros in on as little as 12volts by installing a bus across to posts on the motor. Could this same type thing be done with a controller or say steering wheel mounted switch or paddle? You would have to have a control to reverse the motor anyway. -- Mark Price Morgantown, WV 1969 AMC Rambler, 4.0L, EFI, T-5 -------------- Original message ---------------------- From: Frank Swygert <farna@xxxxxxx> > I think the guy meant energy usage efficiency, not motor efficiency. > Drawing less amps means the motor and controller doesn't get as hot, > and the batteries aren't depleted as quickly, so range is increased. > This implies overall efficiency of the SYSTEM (as installed) is > increased. > > I'm trying to figure out what's implied as happening, not taking him > literally. > > > On May 3, 2007 andrew hay wrote: > > > " From: Wrambler242@xxxxxxxxxxx > > " > > " I stumbled on the website that the guy has who built the 4X4 XJ EV. > Url is at work. Google should be able to find it, try EV Jeep or > somethignt o that effect. > > " Anyway, he says that electric DC motors get the best "economy" by > running at their rated rpm. > > > > i think he's talking through his hat. electric motor -efficiency- > is > > not dependent on speed. > > > > it may be true of -his- installation, but he's made choices limiting > > his flexibility. maybe even some choices he's not aware of, imho. > > > > " If you think about it lugging an electric causes a need to increase > the amperage to maintain rpm. > > > > you mean overloading it, demanding more hp? that takes more current > > at any speed. > > > > " So a 4 speed non OD trans would in fact be a fairly good tool to > allow one to be able to keep the motor at the "sweet" spot. > > > > electric motors [with electronic controllers] don't have a sweet > spot, > > unlike internal combustion engines. they usually have constant > torque > > [within thermal limits] up to a certain speed, then constant hp > above > > that. if he's not getting that, he's not getting everything he > could > > out of his motor. > > > ________________________________________________________________________ > > > Andrew Hay the genius nature > > internet rambler is to see what all have > seen > > adh@xxxxxxxxxxxxxxxxx and think what none > thought > > _______________________________________________ > > Amc-list mailing list > > Amc-list@xxxxxxxxxxxx > > http://www.amc-list.com/mailman/listinfo/amc-list > > > ============================================================= > Posted by wixList Archiver -- http://www.amxfiles.com/wixlist > > _______________________________________________ > Amc-list mailing list > Amc-list@xxxxxxxxxxxx > http://www.amc-list.com/mailman/listinfo/amc-list _______________________________________________ Amc-list mailing list Amc-list@xxxxxxxxxxxx http://www.amc-list.com/mailman/listinfo/amc-list