# AC50 and medium sized cars

5585 Views 11 Replies 6 Participants Last post by  JRP3
The AC50 seems to have the highest profile of the AC Motors but I read varying anecdotal reports of its capability around hills. Chinese BLDC motors are looking very promising as an alternative.

On my commute I have a hill climb that has to happen. My car is a BMW 318ti. I am doing all my calculations at the GVMR 1555kg just in case.
The hill is a 4.6 degree angle (8 percent incline). I have calculated this to require 30-35Kw, and as it is 2km I will need to hold this for 90 seconds. If I do 1:1 through a transmission to the 4.44 diff then 3000 RPM will do 80km/h - sounds perfect. (Side question: I haven't decided whether to modify the auto transmission or put in a two speed transmission yet, but understand the former may add significant losses - any idea how bad?).

Either way, is this motor up to it? The chart says it can do over 40Kw at 3000 and at that point still has its 150 maximum torque.
http://hpevs.com/Site/images/jpeg/power-charts/pdf/ac50_102v_650a_metric.pdf

However people quote 50kw as its peak performance. So is this graph all peak readings? If so, how long is it reasonable to expect a motor to operate at peak for? And what if one added a water cooling plate to this motor (and to the controller), what impact would that have?

Richard
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Now, make that a 3400 lb vehicle and 2 km long 8% grade and I would expect around 800Wh/mile and around 50kW power at the same speed, and about a 2*1.06*50/21 = 5C temperature increase. Peak shaft power of the motor with the 650A controller should be around 60kW with a 115V nominal pack. Hopefully this is within +/-30% of actual performance you would get, but no guarantees.
I think this part was mint for me . I will be running a 5.50-1 to a 7.30-1 gears in the car . But if you really think I should use the DC motor in my car .....well I guess ....OK . "But" , 200Ft lbs is great at 1500 RPM on built 5.0 H.O . My street racing engine only had 175Ft lbs at 1500RPM . And if that AC-76 set-up can do 8000+ RPM , I'm in heaven !!
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