# Best motor for 2900 pounds curb weight



## Nathan219 (May 18, 2010)

What is your fuel economy on average at your driving speed? This will let us know how much energy your vehicle requires to drive the way you want to drive it. It is then much simpler to suggest a motor. 
Sorry I couldn’t give you a simple answer. 

45% thermal efficiency according to Wikipedia for diesel engine 

38.6Kw per gallon of diesel fuel 

38.6*0.45=17.37kw of useable energy to move a vehicle 

17.37kw/(miles per gallon of your diesel vehicle) = Kw per mile to drive your vehicle

Also 
If you know the average speed you drive your vehicle this can tell you the size of the electric motor you need 

(Kw per mile)*(average speed in mph ) = Kw needed to go this speed 

I would give myself a big fudge factor here automotive manufactures do, they have rate their motors in peak hp. The more power you have above what is required will decrease the time required to reach your cursing speed and increase the fun quotient. 
Since electric motors are rated in working kw or horsepower the motor and controller you select should be at least this large
A typical electric motor controller exceeds 80% efficiency 

(Kw needed to drive vehicle / 0.80 electric motor efficiency)* range desired = battery pack size for range 

Just for fun look what adding AC does to your vehicle battery pack requirements

(Kw needed to drive vehicle / 0.80 electric motor efficiency)+ (0.0638 Kw for air-conditioning) * range desired = battery pack size for range with air conditioning


Good luck


----------



## mizlplix (May 1, 2011)

Koper, you are in about the same situation as I. My car is 2,500-2,800# when done. (Estimated) 

I want 70 MPH or so top speed and mostly 45 MPH driving. 

With an AC50....and it's RPM range, I only need 2 gears. Yes, I have a T-5 5 speed, but it is wasted on where I live. (Flat terrain, urban/suburban driving.)
18 miles to work. I have a powerglide.

I will eventually be running 4.10:1 rear gears, with a 30" tall tire. 

If I went DC, I would have retained the T-5 and a clutch. 

These "guesstimates" are based on 14 Months of every day driving a Jet Electra. 
It had a 20HP Dc/4speed drivetrane, and was a little anemic at times. I used all 4 gears and could have used a fifth on the expressway.


----------



## cruisin (Jun 3, 2009)

A AC-50 will do a nice job for you and give you that all important regeneration which is more effective with a 2900lb car than one like mine which is about 2200lbs. I had a Impulse 9 with a 1000amp controller before and changed to AC-50 (because I sell them I wanted to be more familar with their use) and am happy with the results. I believe the DC with a 1000amp controller gave me a little more torque in the low RPM range, but the AC does a better job in the upper RPM range. The controller gives you a VERY smothe motor control unlike the DC. The ability to program so many parameters is awesome. Its a winner. email me at [email protected] if you would like more details on the AC-50 or anything else I can help you with. Ex EV conversion instructor.


----------

