Hi, Well, I've got the front suspension and axles out of my VW Pickup right now. The axles are being rebuilt, new stuts inserts, A2 Jetta springs, new rubber and most certainly new wheel bearings. While doing this I plan to build a lower control arm frame connector. That will run right under the tranny, and I'm wondering about my current choice.
Its a 120v system with a Prestolite MTC 4001 motor. This is a rather low rpm per volt, high torque per amp motor, the curves for it are closer to an ADC 9" motor than the ADC 8" motor is more often compared too. The controller is a 450 amp baby DCP (600 motor amps peak, and about 400 battery amps in practice). The motor comes out of current limit at about 3500rpm. The Pickup weighs about 3300lbs. My biggest concern is freeway efficiency and not overheating the motor, either transaxle I have will be about equal around town. First, the same motor and pack voltage is in my Buggy (Optimas are stiffer, current limit about 3600rpm). At 60mph the motor is turning 4200rpm in third (150 amps). There is not alot of throttle left, but with such a light vehicle I don't need much power to easily maintain speed up freeway grades. Now my Pickup gearing choices: 1. The tranny in there now runs 3700rpm at 60mph in 3rd. I have gotten the motor temp light on once (the motor temp switch seems to be conservitively low temp to avoid damage). But I had a bad alignment, wheel bearing, and still don't have a bed cover. I don't know how much this stuff will help, so there is some blind guesswork here. 2nd gear is 10mph per 1000 motor rpm, sometimes that gets me to use 1st. 4th gear is to tall to be of any use (2450rpm at 60mph). The tranny looks good inside the oil fill hole and all gears are quiet. 2. The tranny on the garage floor is the one that came out of the Pickup. It never moved the Pickup as an EV, but the motor was run attached to it originally. 3rd gear at 60mph would equal 4450rpm. At that rpm I figure at full throttle the Presto will only draw about 200 amps. That is very little throttle reserve for freeway grades. 4th gear may be an option that could be used briefly, 3150rpm at 60mph (this is stock VW Pickup 4 speed gearing). 2nd gear is about 9mph per 1000rpm, so I may be slightly less inclined to find 1st gear (espcially starting on a mild grade). 4th gear in the tranny is a little more noisy that it should be (couldn't hear that over the diesel, but could over the presto). I think the tranny was run very low of gear oil as the oil in it when I got it was clean and amber, but reaching inside the fill hole I could wipe out a black sludge film. I don't know how much harm it has really seen, it does shift just fine (I drove the Pickup about 200 miles as a diesel). OK, what would list members choose, and why? Thanx for the help, Neon
