4hp motors and controllers for a kart?
In the last months, we built an electric kart from salvaged 500W (3/4HP) electric scooter parts (http://electrickart.blogspot.com). With 17AH batteries we can easily run full speed for about an hour and a half which is awesome and gives us a good range (currently 27kph top speed, which gives 35-40km on a charge!). Now we'd like to build a second version, one that can win from the gas guzzling kid karts (4HP) at our local karting club. Our current electric kart is not much slower than the kid karts although we have about 5 times less power, so we're confident we could outrun them with just a bit more electric power on our wheels. We're now wondering how much power we should put in the machine.
I see that many people adopt Etek motors and use AllTrax controllers for their electric kart conversions. This results in a powerful kart at 10HP or 7.5kW, and the results look awesome, but maybe it's already too much for our experiment. I'm afraid that running the motor at a rated 200A will kill any battery in a matter of minutes. Indeed, 40AH batteries will run dead after 12 minutes at 200A. I don't see any mentioning of the battery times or ranges of these karts, so I' guess they will not be much good. (And maybe my computation is completely off)
We're not convinced that we need to bring that much horsepower into our kart, and are now looking for alternatives in the 4-5HP range that may possibly also be easier on our wallet (Etek+AllTrax combo costs about $1000, which is not cheap).
Looking at electric scooters, we love the use of 3000W (4HP) engines in models that can run at least 60kph on a range that is beyond 40km. As our experience with bringing in scooter parts onto the kart was very positive, we're looking for motors and controllers in the 3000W range that could be used on a kart, but the parts should not necessarily originate from scooters.
Do you guys have any shopping recommendations for such motors and their controllers? Has anyone built a 4HP electric kart? What type of motor should we adopt? What kind of voltage, 24, 36 or 48? How much AH should be in our batteries? Where do I go to buy motors and controllers in Europe (Belgium)?
Thanks in advance, Anthony