Choice of motor

There is a jungle of electric motors out there DC, AC, Series DC, permanent magnet and so on. The choice of motor is critical so you should invest some time in it. The fiat 500 R has an 18hp 594 cm³ engine producing about 35 Nm at 3000 rpm, max hp at 4500 rpm.

The original I.C.E without the "shell"

Give the values above and the fact that I will be using the original gear box I started looking for a suitable motor.

A good place to start looking for a suitable motor is http://www.evalbum.com/. You can browse through cars and even find your car model already converted.  The reason for choosing Agni as the motor manufacturer is because of its low weight, high rpm and high efficiency. The only back draw would be that it’s not a brushless motor.

I’ve used motenergy’s (http://www.motenergy.com/) ME0201013001 in my boat and the ME0708 for my mower and they work fantastic. The reason for not using them on the fiat is the low rpm.

This are the specs of the Agni 95-R

· Hi Torque 8" Diameter motor

· Highest Power to Weight ratio

· Kevlar banded for higher RPM performance.

· Bi Directional rotation

· Adjustable Timing

· Easy brush maintenance

Model	rpm/V	max. V	A cont. @48V	cont. output power@48V	max rpm	cont. output power	max. power for 5sec
							kW
95-R	71	84	220	9.5 KW	6000	16 kW@78V	ca. 30 kW

Agni uses the following model to calculate the size of engine for a specific vehicle.

Take the weight of the vehicle, I use 600 Kg, and multiply it with the intended top speed, let’s go for 100 Km/h. This gives me a value of 60000. If the value is more than 30000 you will need a gearbox if it’s lower than 30000 you can go for direct drive.

I’ll use the gearbox on the fiat and the rule of thumb is:

When in top gear with a gearbox, the overall reduction ratio needed will be about 3.6:1 with typical size small car wheels (145/70x12, approx. 20 inches diameter including tires).  The fiat 126 gear box and the top gear ratio is 0,87:1 and the final drive ratio is 4,87:1.

Gear box with integrated final drive

Let's try some math!

The gear ratio on the 4th gear is 0,87:1. The Agni 95-R gives me 71 rpm per volt, I'm guessing this is during a no-load scenario. I will be using a 72 volt system which gives me 71*72=5112rpm 5112/0,87 equals 5875 rpm before the final drive ratio. Rear end gear ratio is 4,87:1 and tier diameter is about 20 inches. This boils down to a maximum theoretical speed of 72 Mph. 

The rpm/v will be lower when under load, approx 4800rpm, and the voltage will decrease during high ampere draw from the battery pack so I'm guessing I'll end up somewhere around 67 Mph.

Interior

What about the interior? The 500 has a simple but nice interior. The interior of the frame is painted with the same color as the exterior of the car, in my case dark blue. Door panels, seats and part of the roof are burgundy.

I wanted to do something about the front seats but I don’t want it to look like a cheap race car. I’ve looked at seats from the new 500 but they are very hard to get.

I would never ever put sparcos in my 500 that’s just rude. It needs a classic look period!

I wanted leather seats with a classic design and adjustable backrest for access to the rear seats. Ferrari would be nice but way out of my price range. Mazda Miata mx-5 has nice small seats but I had no luck getting those either.

What about Porsche? German seats in an Italian car? Someone is bound to be turning in his/her grave. Turns out Porsche seats, 911, are a perfect fit and I was lucky to get my hands on a nice pair in black leather with electric heating and power seat control.

Perfect match if you ask me!

Say what!?

The trees are dying, the water is polluted, the ice is melting, global warming accelerates and I have too much time on my hands not to act on it. I've always had a thing for mechanics and electronics and I love nature. During the last year I've converted my riding mower from I.C.E, Internal Combustion Engine, to electricity and my boat is now sporting a hybrid drive line designed and installed by me.

Everything started a few years ago after I sold an El Camino that I restored. I was so disappointed of the I.C.E's efficiency and wanted to do something that would have an impact on the foot print left by me in this world.

So let's cut to the chase! I'm converting a Fiat 500 R from 1973 from I.C.E to electricity. Why the 500? Well, first of all, it's the most beautiful car in the world. It's also a light car with very low drag coefficient drag coefficient.

Here's some data taken from wiki:

Manufacturer	Fiat
Production	1957-1975
Assembly	Turin, Italy
Predecessor	Fiat 500 "Topolino"
Successor	Fiat 126
Class	City car
Body style	2-door sedan 3-door estate
Layout	RR layout
Engine	479 cc I2 499 cc I2 594 cc I2
Transmission	4-speed manual
Wheelbase	1.84 m (72.4 in)
Length	2.97 m (116.9 in)
Width	1.32 m (52.0 in)
Height	1.32 m (52.0 in)
Curb weight	499 kg (1,100 lb)
Related	Autobianchi Bianchina
Designer	Dante Giacosa

We are talking about 500 kg's of steel driven by an air cooled I.C.E producing a maximum of 22 hp. It supposed to be a four seater, but I don’t know about that.

The picture shows the convertible but I have got my hands on the one with the sun roof. As you can see the car is a rear wheel with gearbox, engine, differentials and driveshaft all built into one unit mounted in the back of the car. The fuel tank is located in the trunk in front of the driver there is not really any space for luggage.

After a year of looking through car magazines and adds on the net i found a 1973 fiat 500 R in the outskirts of Stockholm. I went to see it and to my surprise the car was in great shape. The body had been restored, new floor pans, new doors, new hood and so on. The drive train was of unknown state but a working engine + gearbox was included in the buy.

So I ended up buying a grown man's LEGO. Thousand parts to play with. Perfect!

Love at first sight

Room for inspiration

Smelly!

The first thing that needed to be done was to remove the engine and to start to work underneath the car. Suspension arms, springs, breaks and shocks, everything had to be overhauled.

As you can see there was still some rust and dirt left underneath the car.



Fresh!



Turns out the engine had been overheated and it did not turn.



New adjustable shocks and some paint job. Looks as good as new.

I had a couple of hours left of my spare time so decided to restore the I.C.E just for fun. It's a shame it's such a polluter because it’s a nice little machine. The engine block fits inside a standard stove, but don’t tell Lisa about that.

Engine and gearbox ready to be fitted in the car

Lights installed. All light bulbs except head lights are LED's

Sun roof in place

Drivetrain in place

Work is easier when there is no rust

Test drive

So the drive train is in place and everything seems to be working, but wasn't this supposed to be a story about a conversion? That's right! The main reason for installing the original drivetrain was to get all the measurements correct.

The plan is to keep the gear box and the clutch but replace the I.C.E with an electric motor. I will keep the clutch and the flywheel.

The flywheel is situated 99mm from the gearbox. The adaptor plate between the electric motor and the gearbox needs to be designed so that this measurement is not altered.