Ben Nelson's Electro-Metro Build thread

[bennelson]

I did a quick test of how long it takes the Electro-Metro to go from zero to 30 mph in 2nd, 3rd, and 4th gears.

This was me taking off from a dead stop onto the main road in front of my house. It's actually just a tad uphill from the stop, the the first section of the main road is pretty level.

In second gear, it took 17 seconds to get to 30 mph. It had real good acceleration from 0 to 25 but was slow to get from 25 to 30. That's exactly where I normally would have shifted in a gas car.

In third gear, it took about 13 seconds to go from zero to 30. Easy to pull away from a dead stop, and the motor wasn't over-revving at 35.

Fourth gear was also about 13 seconds, but takeoff was real slow and pulled lots of amps, once it got going, it got going fast.

This car really likes third gear. I can put it in third. Pull away from a stop and have smooth speed up to a little past 35 mph. After that, I shift to fourth.

To upshift, I need to pull the stick to neutral, and then wait a few seconds, THEN put it in the next highest gear.

Downshifting is difficult without a clutch.

The camcorder rode shotgun with me, so expect a YouTube video soon.

EDIT: Here it is!

http://www.youtube.com/watch?v=qSbPN_HaFHI

I also just calculated last night's "fuel economy". It cam to just under 119 MPGe. Guess that's may penalty for running the batteries all the way down!!!


PS: Note the product placement T-shirt!

[MetroMPG]

I noticed the t-shirt. Way to represent.

0-30 in 13 seconds is totally respectable. I bet nobody would even honk at you.

Nobody's ever honked at me, but the ForkenSwift takes around 25 seconds to accomplish the same thing. (I also make a point of driving on "side roads" though. I have video, but I'm way behind on editing them into YouTube flicks.

Ivan says someone honked at him one time...

Nice work!

[Vince-HX]

thats seriously cool

Has anyone tried adapting a turned down flywheel to the electric motor so you could keep the stock clutch? Seems like it would make driving a EV that much better. Would it be more efficient to be able to use 1-5 gears?

Projects like this make me want one bad, lol

[bennelson]

1st and 5th are completely useless gears in this car.

1st gear spins up really fast and isn't needed, because you can pull away from a stop in either 2nd or third.

5th just doesn't have any power with the gear, weight, and voltage of this system.

An EV can be built with or without a clutch.
You even CAN build one with an automatic transmission if you really wanted.

Usually the flywheel would not be shaved down, but rather buy or build a custom version of what a shaved flywheel would be like.

Machining something like that is beyond my skills. Buying or having one made would have been a budget buster.

This car drives like a golf cart in 3rd gear. You can pull away from a stop and go up to a little over 35 mph without shifting, using a clutch, or have anything weird happen when you come to a stop.


Just to compare, here is a video response to my YouTube video from another EVer:

http://www.youtube.com/watch?v=nZCfyQz9ZWU

Looks like his shifts a lot nicer. He's also using Optima Yellow Tops, which I know you can pull a LOT of amps from!

[MetroMPG]

I must never ride in a car like that or I'll hate driving the ForkenSwift after!

I can't believe we drove it for as long as we did with the 225A controller in it. 35 seconds 0-30 mph...

[bennelson]

Not sure if I ever mentioned it or not, but I made a poor-mans' shock absorber for the motor end mount, and I installed the big ammeter and voltmeter in the dashboard where the radio was.

That looks much more "normal" without the giant meters duct-taped to the dashboard.

My "custom" motor end mount is just a turn-buckle with an eye-bolt on each end. I figured that way, I adjust the length or tension between the motor and the frame of the car.

The top eye-bolt is bent over far enough to angle into where the original engine mount was, and simple has the engine mount's bolt go through the eye of the eye bolt. This was a lot simpler than trying to manufacture or weld something between the engine mount and the motor.

The problem was that there was still a little space between the bolt and the eye-bolt's eye, so I still got the "ka-lunk" everytime I accelerated from a dead stop.

I finally resolved that by making a rubber spacer. I took some rubber hose, slit it, and put it around the diameter of the cross bolt, then put that whole thing through the eye-bolt. It fit almost perfectly! Now there's some rubber in there and no more "ka-lunk" sound!

I promise to post some photos of the the eye-bolt and mounted meters soon.


EDIT: This one isn't very good, but at least you can see where the meters are and about how they look.

[MetroMPG]

After watching your acceleration vids, I've changed my technique when I want to accelerate quickly. If I'm starting from a stop, I'll use 2nd or 3rd and upshift to 4th pretty early. I think I'm doing much better than 25s to 30 mph now. Hard to believe I'm still figuring the car out.

[bennelson]

I taught you something?

LOL!

[bennelson]

I just checked my Killawatt for how much energy was used to recharge from yesterdays driving.

It came to just under 280 watt-hours per mile as measured at the wall, which is about the equivelent to 130 MPG!

I showed the car last night to a guy I work with quite a bit.
I drove the car to a parking lot just off the freeway for him to pick me up and us ride together with his equipment out to a gig in Madison, WI.

I still had the hand-written flyer in the back window that I made for the Electric Utility open house. He saw it and asked "That's an electric car?!?!"

We had to get going right away, but he wanted to see it at the end of the day. I did mention that reverse is still a bit touchy, and there's a few other things I still have to do on it.

When we got back, I put my gear in the car and then threw it in reverse. The first thing he did when I quickly backed out was to burst out laughing. I don't think he was prepared for how quick the car can be, especially without going "vroom vroom" first.

I did a few circles in the parking lot, then said good night, and drove home.

Total round-trip: 9.9 miles.
Gasoline used: 0

[Daox]

Haha, very nice.

*grumbles about wanting a 130 mpg car* I want one!