# Which Motor?



## dougingraham (Jul 26, 2011)

Are you planning on having some sort of transmission? That would let you match either motor better and give you more torque down low.

If you reduce the AC-15 an additional 0.75 the torque curves are similar. But from the chart it looks like the AC-15 is a little more efficient since its peak HP is 44 vs the 37 of the AC-12. If you can't change the final drive ratio so that both are at 4000 RPM for 60mph then the AC-12 is down to 35 ft-lb at 60 and the AC-15 is down to 58 ft-lb. You are going to see the torque drop sharply with the AC-12 at about 40 mph. This may feel a bit strange when it happens. It will feel like you turned the throttle way back.

You might look at running the motors at a higher voltage. A higher voltage would widen the torque band on the AC-12.

Best Wishes with your build!


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## WorldPax (Feb 15, 2015)

Thank you. No transmission other than the sprockets since it's a motorcycle drive. I think you confirm what I expected. If you take the average torque from 0-4000 rpm on both they come out pretty even, but the AC-12 is falling on it's face by then. 

I may just find the extra $500 and call it done with the AC-20 @ 72V. Bigger torque and flat out to 4000. Sticker shock is getting me a bit, but I know I'll regret it if I don't over power it a bit with MORE POWAAAW!!! All relative of course.

I'm sure there's 50 guys on here who could get this done for cheap, but I'm not skilled enough for anything other than a straight forward kit.


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## rtz (Jul 3, 2013)

Jack is having a big HPEVS sale. I'm sure he could order it for you: http://store.evtv.me/products.php?cat=11


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