Hello John,
I just came back with a test drive with my new li-ion battery pack, pushing through 6 inches of snow up a 1/2 mile hill and had it in idle control (Label Idle) which is about 300 motor rpm to a get back down. The idle control is just another 5K pot I put in series with the accelerator 5k pot. Use a double pole 2 position rocker switch on the dash to switch the 2nd 5K pot in series with the accelerator 5k pot for idle. I found with the Café Electric motor controller that I am using, about 300 rpm will still allow the motor controller to come on. Switching the 2 position rocker switch to the NO IDLE position removes the 2nd 5K pot from this circuit which puts in the normal accelerator control. I normally start up the motor controller switch in the normal position or (NO IDLE) to start up the controller. Then I switch the rocker switch to the IDLE position. Just turning on the switch to idle, I can back out of the garage or a parking space without pressing the accelerator. I am using a GM-TH400 automatic transmission converted by TCI.com to a manual selection of gears. They install a manual valve body, block off the inlet port for a vacuum modulator which is not need and remove the governor control. A torque converter was use to match the sweet spot rpm which the motor hp and torque is at its maximum. I using a 11 inch WarP-11 which the sweet spot is about 1800 rpm. The motor ampere at this rpm is about 200 amps which happens to be the continuous rating of this motor. I used to have a 9 inch Warp-9 in the EV with a sweet spot rpm of about 3300 rpm. The WarP-9 at a 3300 rpm sweet spot was out of range to drive at 25, 35 and 45 mph which is all of my town driving. Above or below these speeds, I could not drive the EV at the best RPM/HP/TORQUE efficiently. Either the torque was too low causing the motor ampere to be too high at different rpms. It will depend on your driving needs of which motor to use. TCI.com sub jested a 12 inch diameter torque converter that has a full lock up rpm of 1700 rpm which is close enough to the 1800 rpm sweet spot. This torque convertor starts to lock up at 300 rpm with a transmission oil pressure starting out at 150 psi which raises up to 180 psi at 1700 rpm. I use a on dash oil pressure meter to record the transmission oil pressure. The low rpm starting lock rpm will depend on the overall gear ratio you have selected. A torque converter right at the starting lockup counts as gear ratio. Many torque converters will have a starting gear ratio of 1.7 to 1.8 ratio. For example my torque converter gear ratio at 300 rpm is 1.8:1. If I selected the first gear of my transmission which is 2.5:1 and the differential gear is 5.57:1 the overall gear ratio is 1.8 x 2.5 x 5.57 = 25.065 to one. In reverse gear its over 27 to one, this is why I can back out of a parking space at 300 rpm. The GM-TH400 is a heavy duty built transmission, which the transmission shops said they may only get one in for overhauling for every 1000 other transmission to be repair. Lets say you have a 3-speed transmission with a torque converter, it feels like a 6 speed transmission. I start out at 300 rpm with a overall ratio of about 25:1, as the rpm gets up to the lock up rpm at 1700 rpm, the 1.8:1 ratio goes away leaving 2.5:1 first gear x 5.57:1 differential = 13.9:1 over ratio. Its like a variable transmission between two fix gear ratios. When I shift to the next gear, the some of the torque converter ratio kicks in, thus another 3rd shift ratio and when the torque converter ratio goes to 0.0 ratio, becomes a 4th shift ratio and etc. My weight of my EV with 2500 lbs of lead batteries weigh in at 7030 lbs. Had to start up in 1st gear to keep the motor ampere at or below 200 amperes. The motor ampere was about 75 amps. Normally shifted into 2nd gear which was left there all the time. My weight is now 5400 lbs with 750 lbs of Li Ion graphite batteries which are 45 volts higher than the lead batteries. I now can drive up steep hills at 25 to 35 mph in the 2nd gear and was able to shift to the third gear, maintain the sweet spot rpm at 1800. Just installing the automatic transmission increase my range from 39.9 miles (50% SOC) to 56 miles with the lead batteries. This was also achieved by after accelerating up to speed, I turn off the idle switch which lets the motor drop in rpm using no motor ampere as the EV coast down. Coming to a stop (the idle switch is off), I will turn on the idle switch first before I press the accelerator. This reduces the motor/battery ampere surge which could goes as high as 500 motor ampere and 150 battery ampere. Roland ----- Original Message ----- From: John Lussmyer via EV<mailto:ev@lists.evdl.org> To: Electric Vehicle Discussion List<mailto:ev@lists.evdl.org> Sent: Wednesday, November 26, 2014 9:07 AM Subject: [EVDL] Converting with an Automatic Transmission So, just what needs to be done to convert a vehicle with an Automatic transmission? Do you HAVE to "idle" the motor? (can a zilla do that?) Or is there some other Not Impossibly Difficult way of dealing with it? (Thinking of converting another truck - but pretty much all have Automatic transmissions.) -- Worlds only All Electric F-250 truck! http://john.casadelgato.com/Electric-Vehicles/1995-Ford-F-250<http://john.casadelgato.com/Electric-Vehicles/1995-Ford-F-250> _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub<http://www.evdl.org/help/index.html#usub> http://lists.evdl.org/listinfo.cgi/ev-evdl.org<http://lists.evdl.org/listinfo.cgi/ev-evdl.org> For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA<http://groups.yahoo.com/group/NEDRA>) -------------- next part -------------- An HTML attachment was scrubbed... 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