[Pirape]

I cannot find this information anywhere...

my mitsubishi lancer ICE develops @ peak 120HP...around 5000 RPM

lets say I wanted to keep the same performance with an electric motor

should I go with a 120HP motor with 89 000Watts peak power?

In my head this does not make sence because I am never never driving my car in the 5000 rpm... Im guessing my car has 30-40hp at 2000 rpm where the sweet spot for fuel economy is....

Can anyone clarify this for me?

Thanks

 

[rwaudio]

Here's a dyno run of a slightly higher hp lancer, it doesn't go down to 2000 rpm but it gives you an idea of the hp curve atleast.

http://www.dragtimes.com/2006-Mitsubishi-Lancer-Dyno-Results-Graphs-12846.html

 

[Woodsmith]

Interesting thing on the dyno result is that at 50mph it requires 11.7hp to overcome rolling resistance.

 

[Pirape]

Interesting thing on the dyno result is that at 50mph it requires 11.7hp to overcome rolling resistance.

that is what I mean... Do I absolutely need a peak 120hp motor? when 50mph = 11.7hp?

to travel at 50mph I would need a nominal 8728Watts of power to push around the vehicle...

Im sooo confused

 

[Woodsmith]

that is what I mean... Do I absolutely need a peak 120hp motor? when 50mph = 11.7hp?

to travel at 50mph I would need a nominal 8728Watts of power to push around the vehicle...

Im sooo confused

No you don't need 120bhp.

At 50mph you would have 11.7hp in rolling resistance plus a bit in aero drag, you could say the same again, depending on how 'slippery' the car is.

You may only need a motor with 15kW nominal 1 hour rating and it will probably give you a bit more for overtaking that lorry on an up hill run for a few seconds, depending on your batteries and controller.

 

[rwaudio]

Maintaining speed and getting up to speed are two very different things. Your motor/controller/batteries should be capable of atleast the "maintain speed" power level on a continuous basis, and a peak power level of your desired acceleration rate plus a little extra so you aren't pushing it to the max every time you accelerate.

There is a great excel sheet, I'm sure I found it in the wiki that lets you put in weight/drag acceleration rate, it gives you power required, power to maintain speed etc. I'm sure it's not perfect but it looks like it would give a good ballpark number as far as power and all that goes.

It's called evdrivepower.xls
Hope that helps

 

[Woodsmith]

It's called evdrivepower.xls
Hope that helps

Here's a link.

It is very similar to my own simpler spread sheet but I don't have acceleration or gradient and I only calculate for each speed I enter.

 

[DavidDymaxion]

Here's a real life metric:

40 to 50 hp for 2000 lbs vehicle: Old VW bug and VW diesel. Barely adequate for highway work, really better for city speeds, you'll definitely hold up traffic on hills.

100 hp for 2500 lbs: Modern economy car, adequate and safe.

300 hp for 3000 lbs: Sports car territory.

My electric currently has about 50 hp. It's adequate for city speeds for level ground, it'll even do low highway speeds, but I consider it inadequate for hills in traffic or freeway traffic.

 

[tomofreno]

Here's a link.

Looks very much like the first part of a spreadsheet I developed in 2008, which can be downloaded here:
http://electricnevada.org/#calc