Sunday, February 12, 2012

Fun, But Not a Race Car

The electric car is configured to limit the motor to 5,500 RPM. First gear breaks the tires free so fast that it's not really useful.

Starting in second gear is better, but the motor RPM limit means shifting is required just past 40 MPH. It's fun off the line, but the time required for a clutchless shift hurts the 0-60 time.

Starting in third gear works. That goes from 0-60 in 9.4 seconds.


  1. 9.4 seconds is very decent acceleration...but the zero to 40mph is crazy fast (nice!).

  2. So how does it compare to the "stock" Z3. This is pretty awesome!

  3. Bruce,
    This is really impressive! What are you using to measure your 0-60 time? I recently tried to measure the 0-60 time for my MR2 electric car using both an Android app called GTR (paid $3.99 for it) and an iphone app called pocket dyno. I got 10.5 seconds for the pocket dyno but wasn't able to reproduce with the GTR app. My build is a 144V Advance DC motor with a modified 1231C curtis controller capable of 750amp draws and 45 180ah LiFePO4 cells.

    1. Hi Ken, I just used an iPhone to record video of the speedometer. I'll check out GTR and Pocket Dyno.

  4. Ah, good idea! Sometimes low tech is better than high tech. I'll give it a shot sometime this weekend!

  5. Did you consider direct drive with the transmission removed? Is it a 5 or 6 speed? It always amazes me the Tesla goes without a transmission and it seems like a motor might fit where the transmission was in a BMW.

  6. The acceleration is much better with the transmission. In fact, 1st gear is useless because it starts so fast. 2nd gear is best for racing and 3rd is what I usually start with. But I've been considering removing the transmission because I'm not really racing, it would save 150 pounds, it would be even quieter and it would free up space for an iPad/iPhone to display battery details.