LEAF Dyno Run

[DaveEV]

Cd alone is not the whole picture. You need to look at both Cd and frontal area. Thus a car with a low Cd but high frontal area can have more drag that a car with a high Cd but low frontal area. You need to look at the product of both to get the true drag picture.

Yes, but the frontal area of a LEAF and Camry is probably very similar.

 

[sparky]

Overlay of my 0-60 CANbus data onto the dyno plot. I plotted horsepower (V*A/746WperHP) vs MPH.
Slope lines up pretty well. Peak was way off, as in my peak was ~120HP. Scales very close to peak dyno HP when multiplied by 0.9 which indicates ~90% efficiency between battery output and motor output... perhaps.

 

[LEAFguy]

Sparky - great info. Neat to see the correlation like that. In the earlier link to the SAE ev magazine, if explored you will find a graph of the LEAF drivetrain efficiency. It varies from 85% (worst case) at either end of its operating range to 95% in the sweet spot from 45 mph to 63 mph. With those efficiencies factored in, I bet your curve would look very much like the dyno plot.

 

[JohnOver]

Awesome stuff there.

Figuring the motor RPM should be very straight forward, and at 95-ish mph, you should have had 10,300 RPM, therefore 47.5 mph would be 5,150 RPM. Right there is your torque / hp equal mark, so 105 hp was about 105 ft/lbs of torque.

I get about 212 ft/lbs of torque at [edit: about 3200 RPM], assuming 105hp there. The motor is definitely AC, as there is an inverter for the battery (your valve cover under the hood).

You could reasonably guessimate the RPM at various points to determine torque using the classic formula, HP = (Torque x RPM) / 5252

http://en.wikipedia.org/wiki/Horsepower" onclick="window.open(this.href);return false;

I took the torque and RPM numbers from the article and plotted torque and horsepower. The HP curve looks a lot like the dyno run...

. I'm not sure how to send the excel file, but I'm happy to send it to anyone that 's interested.

 

[TonyWilliams]

I'm not sure how to send the excel file, but I'm happy to send it to anyone that 's interested.

Upload it to http://bayfiles.com" onclick="window.open(this.href);return false;, and then post the link here !

Easy and free.

 

[garygid]

Yes, Battery Pack output power is more than the Motor output, due to:
1. Climate Control power use
2. Car Electronics usage (charging the 12v battery)
3. Inverter loses
4. Motor losses
5. wiring losses.

I have seen 240A reported on the EV-CAN bus (apparently amps coming out of the Battery Pack).

We also have what seems to be Motor (or inverter) current (or power, unknown scaling).

It would be really helpful to find the Battery Pack (and other) temperatures.

 

[LEAFfan]

If you don't have a personal website to upload the images to, get an account at one of the popular hosting sites (Flickr, Photobucket, Imageshack, etc.) and upload them there.
TT

I use http://tinypic.com/" onclick="window.open(this.href);return false; because you don't have to sign up (get an account) to use it, but those others you do.

 

[JohnOver]

Upload it to http://www.bayfile.com" onclick="window.open(this.href);return false;, and then post the link here !

Easy and free.

That doesn't work for me. I get a URL not found error...

 

[JohnOver]

Upload it to http://www.bayfile.com" onclick="window.open(this.href);return false;, and then post the link here !

Easy and free.

That doesn't work for me. I get a URL not found error...

bayfileS.com...

Okay, here's the link to the spreadsheet: http://bayfiles.com/file/Ypl/R5Xlm6/Leaf_Torque_%26_HP.xlsx

 

[JohnOver]

Here's a picture of the chart that's in the Excel file above.

Thanks for the file sharing help everyone.

 

[nader]

So the question now, is how do we swap a more powerful motor in or get some ECU tuning done to custom tailor drivability?

 

[Herm]

So the question now, is how do we swap a more powerful motor in or get some ECU tuning done to custom tailor drivability?

ECU tuning to free up the temperature and power limits put on the various devices, we dont need no steenking limits!.. reminds me of the classic movie THX 1138, where they have the car/motorcycle chase scenes and the electric Lola T70 overheats and temporarily shuts down. Coolest car chase scenes ever, and in a movie from 1969. George Lucas has always been a motorhead.

http://www.youtube.com/watch?v=Ox8t6CEGoQ4" onclick="window.open(this.href);return false;

This clip shows the temperature gage, but without GCI and the original sound track:

http://www.youtube.com/watch?v=KgPoDgxCQz8&feature=related" onclick="window.open(this.href);return false;

 

[jumpjack]

I found this old but very interesting excel sheet for vehicle performance comparisons:
http://www.offroadvw.net/exceldyno" onclick="window.open(this.href);return false;

How could I fill it up with some EV data?

 

[miscrms]

Sorry to dredge up such an old thread, but here is the info I came up with from a variety of sources to compare several popular electric motors in the excel dyno linked in the post above. Leaf Dyno entry is the data from this thread.

The excel sheets gets a bit messed up occasionally when you use a 1 speed transmission, but other than that is fun to play with. I am transplanting a Leaf drive system into a very light (~1800-2000lbs estimated) very aerodynamic (first gen insight class) 1973 Saab Sonett III. At least on "paper" I was very pleased how well the Leaf system held up against these other options, including the high end dual AC-35 once gear ratio is corrected for same top speed. Acceleration numbers are a bit unrealistic as I had to set tire friction unreasonably high to eliminate wheel spin, but still should be fun

The primary calculations are with the Leaf motor, and the Ghost Car (and acceleration number in the far right scratch space) are for the dual AC-35.

Rob

 

[aqn]

I am transplanting a Leaf drive system into a very light (~1800-2000lbs estimated) very aerodynamic (first gen insight class) 1973 Saab Sonett III. [...]
Rob

Wow, beauty and brawn! How long do you think it will take?

 

[miscrms]

Click on the threads in my sig for updates, its coming along well. Hopefully have a phase 1 "driving test platform" in another month or two

Rob