The Doner Car

I’ve got to admit we’ve pushed it to a new level. I’ve worked day and night to make this EV a reality. I would like to thank Mr. Mark Taylor and my electronics wizard Mr. JD for the time and effort they have put in, pure magic boys.

The weigh in.

The clients dropped off the Echo. They drove her down all the way from Qld. Quite a drive which I’ll tell you about later. It was a clean 2002 echo witch I checked out from stem to stern and found a present “boxy type” sub frame with tones of potential. Its so simple when you have a square sub frame. You can see where everything will go and as for room! There’s lots to be had in a vehicle such as this.

After a talk, coffee and showing them around I drove the clients to the airport in the Echo and wished them well. I’ve got to admit the Toyota Echo is lacking a little in power. Its nimble but has nothing in the acceleration department. You have to literary have your foot to the floor to get some decent response from it all the time and I’m going to fix that.

So to the weighbridge! With half a tank of gas she weighed in at 900kg precisely. With 560kg over the front axel and 340kg over the rear.  So most of the weight is in the front, which is normal for a FWD vehicle. When it comes to balance you have to know where your weights are because the manufacturer sets up the suspension to do the job assuming even weight distribution and when it comes to putting everything together I suggest keeping it relative.

The evil

Lets tear her up.
 Mr. Taylor came to the party with a bunch of tools and a mission “remove the ice and all its evil” and he did just that. This man can tare out an engine and anything to do with it in a matter of hours, nothing gets in his way. Mark had the engine hanging from a hoist, the exhaust removed, radiator drained and leaning up against its engine, and a bunch of nuts and bolts in an ice-cream container in time for morning tea.

no more evil

The coupling

I’ve got a motor and a transmission for the machinist and she’s got to go together so lets talk about the differences. The original ice is a 4-cylinder fuel injected DOHC engine capable of 63kW at 6000rpm and 122Nm of torque at 4400rpm. We’re replacing it with an 8 inch Advanced DC motor capable of 62kW at 120V and well over 150Nm of torque with a Curtis controller. The question is can the transmission take it?

Rear battery box

Battery Installation

The rear sub frame is all straight lines so it’s a pleasure to cut out the tire well. This was done with in minutes with an angle grinder using the appropriate disk. In its place we installed a 1.2mm thick stainless steel battery box containing 22 of the 38 Thundersky lithium ion batteries as well as the zivan charging systems and relays for the charging sequence. It’s a tidy package that’s compact and protected via a reinforced steel bar welded in place behind the bumper and lined with melamine. The compartment is complemented by the same 1.2mm thick stainless lid incorporating an easy access inspection hatch. It’s also ventilated not only while running but while charging too. The zivan really kicks out some heat when it’s at full bore. Why are we ventilated while running when we have a bank of lions? Qld is a sub tropical environment and I want to make sure the compartment is cooled at all times.

mount up

Here where the fun starts, I decided to do the entire front section in stainless steel. But before that we have to mount the new motor. The easy way to build an electric vehicle is to use what you have so we did. The motor is mounted using the original engine mounts with one minor modification. The front or drivers side mount is complemented via a 3mm plate that incorporates the aircon pump welded to a 50×50x5mm angle directly bolted to the original mount. This is about as strong as it gets so the motor will probably give out long before the mount does (did I mention electric motors don’t need servicing for about 8 years?).

The compact

So with the motor in place we need to trim back that pesky wiring harness. People, be careful when doing this and take your time. When dealing with a wiring harness you have to respect the maker and only cut one wire at a time while checking constantly. Ask yourself every time you cut a wire “does the instrument cluster still light up? Does it still do what it did when it had and ice? Did I buy that service manual with the wiring diagram?” Take care and you’ll get it right.

My bigest fan

This vehicle is keeping its aircon system so we need to make a few mods to the existing setup. Firstly we need the motor/aircon condenser cooling fan however it’s mounted directly to the radiator, which is mounted to the frame of the vehicle. I make up a few mounts and installed it as close to the condenser as possible directly on the subframe. We had to rewire the aircon system so that not only did the aircon pump clutch engage the fan came on as well when you pressed the original AC button.

What a lovely box

Mounting the forward battery box brought forth an interesting problem. In order to keep the batteries in one place and have enough room for adequate clearance so the bonnet shuts we lowered the motor and transmission by about 20mm or about ¾ of an inch. This gave us a really clean install as we could simply weld the rear battery box support to the subframe. We bolted the forward support in place as it makes for an easy removal.

So with the framework and battery box in place we turn to the installation of the various components. We need to mount these to something so I lined the gap that was left with a stainless deck. It’s a simple process of getting some cardboard and cutting it to size. Once your happy with the fit cut out the stainless to match and there you have it. I made the deck in sections as it can now be removed independently if the need arises.

Drivers side setup

Where does everything go?
So now our deck is in place we have to figure out where to mount everything. The vac pump is going as close to the booster as possible. Next to that we have the water pump, pot box and of course the controller. After the controller we have the contactor, next to that the shunt and the dc-to-dc converter. Finally we need to leave space for the new compact 12v battery. This leaves us with very little room to move however every part has adequate space around it for inspection. The controllers setting ports are accessible and we can adjust everything. The breaker is going to be mounted on the battery box so its 1, clear of everything elce 2, highly accessible and 3, right under the high voltage sticker.

Passenger side

Many hours of work later we have the client back for a test drive. I made a few connections and took them around the block. For a first drive she responded nicely and surprisingly most EV’s I’ve seen or brought into existence do exactly that. It had more power than the original and it responded nicely. It was smooth and not heavy on the steering. When she cornered she felt nimble and well balanced. So its time to call the engineer for a primary inspection.

Before he came however I had a chance to turn the Curtis up full. The standard factory settings for a Curtis are as follows. The power output is full while the acceleration curve is set to about ¾. This means that when you put your foot flat to the floor it takes time to ramp the motor up to full power. This makes for a smoother acceleration however I feel it’s a little sluggish. At full tilt however everything feels a little sharper. Don’t get me wrong, I like to have the full power of the motor at my control but (and this is the wonderful thing about the ev) learner drivers and people who are not as confident with driving as others can tune the vehicle down to suit their style. This is a simple adjustment and can be done in minutes.

All wired up

The engineer came over and took her for a spin. He took her around the block and tried all the gears commenting on how light it was. Then he tried first from a standing start. The wheels spun as the car lurched forward at a great rate of knots. He backed off immediately as the transmission in these things probably isn’t built to take much more than the original motor. In layman’s terms its like dropping the clutch at the ice’s peek power output. He liked what he saw and gave us a big tick! So at this point we have to do the hard yards and wire everything up to work, as it should when it should.

So while that happens I want to talk further about the components that went into this vehicle. I tried a few experiments and new technologies that worked out nicely. The vacuum pump is from MES-DEA in Sweden. Unlike most of the other vac pumps I’ve seen it’s meant to be in a vehicle attached to the booster. It has an onboard vac switch that shuts it off when the appropriate amount of vacuum is achieved. Its got its own one way valve and because of the fact that in Australia its law that if the engine fails in a vehicle you still need to get two full pumps out of the booster before it fails we don’t need a reservoir.

Heater experiment

One of my little experiments included the use of a micro boiler and water pump to circulate hot water through the existing heater core of the vehicle. Not only is it seamless and fully integrated it draws the same amount of amps as an electric heater core while producing many times more heat. The heater I used was a zero start engine warmer. It takes around the same time as an internal combustion engine to heat up but its pure magic. Basically it works and works well and this is how Convert Ur Car is going to do it from now on.

The final little piece of equipment is a prototype instrument cluster interface. In a nutshell JD built a computer that takes all the information from the various sensors we placed around the vehicle and plugs it into the cluster. The fuel gauge and tacho read as normal for the moment however we are working to install other features and safeties for our future vehicles such as motor rpm and temperature limiting.

The finished product

As you can see we’ve put in even more additional bells and whistles. The forward battery box is covered in Perspex with twin ventilation fans and blue flashing LED’s on the BMS that go out as each battery is balanced while charging. The fuse box is mounted above the dc-to-dc converter. The water reservoir is mounted nicely above the engine mount. Indecently you can pick these up at super cheap auto. The controller is mounted on a heat sink right in the front so it gets maximum ventilation. The old battery fuse box has been integrated and some of its old function has been retained. The dc to dc converted is connected in place of the alternator.

Inside

As you can see we ran out of room in the fuse box and had to plant a relay outside. Another interesting feature is the fact that I installed a relay that prevents the negative cable from the charger from being active unless the vehicle is actually charging. This doesn’t mean that it’s always active while the vehicle is plugged in either. This system only engages when the BMS engages the charger. So when the BMS system shuts down the charger the line goes open circuit and therefore safe.

Rear battery compartment

Well that’s about it for the build side. The engineer passed her with out a hassle, we shipped it up the QLD and I deserve a break. Complications? Yeah there were a few, nothings perfect and things don’t always work first time. The tacho sender for example was loose and I had to pull half the vehicle apart to tighten it up. When I did I broke it and had to order a new one that took a week to get to us. The batteries took eternity to get to us as well as the bms system and its controller.(we have found a new supplier, so this is one issue out of the way). This and a few other niggling things that took a little thought and patience to make happen.

I bet your all asking how much does it weigh now she’s an EV? The echo now weighs in at 1040kg with 620kg and 420kg over the front the rear axles respectively. She gained 140kg in total with 60kg and 80kg once again front and rear making her a 4 seater. We think this is in keeping with the original design. The only other thing we could have done to keep the front rear ratios more even would have been shifting two batteries to the front. However the weighbridge we has a resolution of 20kg so it may be the case of a single battery moving forward to tip the scale.