It's happening again... It has been a little over a year since I sold my Pantera and I'm getting the itch. The itch to drive something really high performance. The itch to drive something that can scare you if you take it just little too far. The Pantera was a so much fun, but I've felt that electric can do even better. Thanks to Kurtis Klein, driving a Tesla P100D confirmed it! I've been around just long enough to know I need to pay attention when I get an itch. In fact, while planning for 2020, I realized that a part of me would literally die if I didn't attempt this project. The part of me that tackles big bold audacious ideas. I fear getting old and dull. So, with the blessing of my wife, Teresa, I'm gonna scratch this itch! The real question for me is how to do this project, not break my bank and to still get performance that will beat my 500 foot/points (ft/lbs), 525 HorsePower(HP) Pantera. That's one tough problem. Enough talking, let's survey the current solutions and areas that appear to be problems.
Lucky for us, the internet has so much information available that the bottleneck is how fast I can read articles or view YouTube. I've spent a fair amount of time reading the postings on Do It Yourself Electric Vehicle forums. There are two areas where a lot of problems occur:
Surveying the motor/controller landscape here shows there are several routes to choose from, but none of them very cheap or easy. First there are AC and DC motors. When pushing parts to their performance limit, all the components need to be matched in strength and it's highly desirable to me to have no wearable parts, so and AC motor is a must. Looking at manufactured solutions, there aren't too many to choose from at this point. Here in the U.S., I've seen Tesla motors, Chevy Bolt motors and Nissan Leaf motor. Both the Tesla and Bolt motors are relatively expensive at $5-10K as a package (both motor and controller). If you choose 'off the shelf' varieties, say from evwest.com , the AC (and some DC) motors are $3K for 'go-kart' type motors to $10K for the really high performance motors. That's *without* a controller/inverter to drive them! Yikes. DC motors and controllers are a little better in terms of price (and low RPM torque) but you loose regenerative braking and have brushes which wear, especially if subjected to high levels of stress. I'm not a fan of maintenance if I can avoid it.
The reader who's been paying close attention will realize I skipped the Nissan Leaf. At first glance the Leaf motors seem too weak at 80 Kilowatts( KW)/ 100 HP. However, they do have about 250 ft/lbs of torque and they are relatively CHEAP at $500-$800 each. In recent news, Tesla has been turning decent lap times on a three motor solution for the model S. If three motors are good, isn't four better? I can buy four Leaf motors for less than price of 1 Tesla motor. Not only that, but there appears to be an upgrade path for the Leaf motors, as one enterprising soul is claiming 300 HP from a Leaf motor after replacing the stock controller and inverter.
The video of him spinning the tires at will, even after moving 30 mph on front wheel drive gives every appearance of a reasonable amount of torque and horsepower. So it looks like I can get started rather cheap on the motor/controller end by going with some Leaf motors and later change the inverter section to get the HP I want if 100 HP increments prove to be insufficient. I'm sure there are cooling issues with running 300% more power than stock, but that's a problem for down the road. Choosing the Leaf motor dictates using a 375 volt battery pack or closer to 500 volts to get some more horse power! Yikes, that means I better get some class 0 electrical gloves for the garage, cause I really *hate* getting shocked, not to mention all those volts can abruptly shorten my lifespan to zero. Lets talk about batteries.
Batteries are both very expensive and time consuming to put together, and somewhat dangerous if not treated with respect. To put some perspective on it, a small 30 mile round trip, uses roughly the same energy as my house does for 24 hours. That implies that a fully charged Electric Vehicle has a lot of power, similar to a gasoline tank. Treat that power with respect. Surveying the battery landscape looks like there are several key areas where I have some flexibility for design solutions.
As anyone who has completely restored/converted a car (electric or otherwise) knows, there is *so* much to do and I could use some help. If this seems to be be of interest to you, leave me a comment on the blog. I'm in the Cedar Park/North Austin Texas area.
OK, enough talking. Let's go get some Leaf motors. Four Leaf motors reserved, road-trip with my son! Will let you know how it goes.