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Old 09-01-2012, 07:49 PM   #39 (permalink)
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Originally Posted by mechman600 View Post
I don't think an unloaded power steering pump takes nearly the power you think to run at a low speeds. For EV purposes, it would have to spin at the same speed as an ICE at idle. When unloaded (not turning on the steering wheel), the pump is simply moving fluid from the reservoir, through the pump, through the valving in the rack and back home to the reservoir. There is little to no restriction and very little energy required. I could see 5 hp at 6000 rpm (ICE speed) and fully loaded against a steering stop, but not unloaded at idle. Less than 1/2 HP, I would guess. Especially with an efficient treadmill motor doing the work. By comparison, your A/C pump will require 100X the energy to run.
I really don't need P/S so I am going to loop it for now and if I do need it I will get a MR2 pump.

We got the A/C compressor mounted with the motor and tomorrow I am going to wiring it up for a test run. I've done some research and 30-40 volts on the treadmill motor seems to be a magic number so that's where I will start.

I have a 2004 Civic that I was playing with today and turning the A/C on and off doesn't seem to use much power in driving or idling. However, the steering pump will cause the engine to rev up. So hopefully tomorrow I'll hook up my current shunt to the PM motor and test to see if it works.
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