Deciding on Parts

So work had me out of town and away from the shop for a week, so progress has slowed.  I did get some time while in California to do some research and order parts.  


Motor Adaptor:  The motor adaptor is specific to the transmission in the car, so the only choices are to find one that is available or have one customer made.  It so happens that the Audi TT shares a transmission with the new VW Beetle and there are many more of those being converted so an adaptor is available from Canadian Electric Vehicles.  The cost of the CEV unit is considerably less than having a unit custom made so the choice was easy.  They also have a good reputation for a well-built product.  On an adaptor from Canada is on it way to Iowa.

Motor:  The first choice is AC or DC.  AC gets you regenerative breaking but the cost are much higher for the same level of performance.  DC gives higher torque and performance but does require maintenance to the brushes over time.  Since the only readily available AC system, the AC-50 from HPEV, lacks the performance that I’m looking for I decided on to go DC.  For DC systems there are 2 paths that can be taken: 1) Start with a used forklift motor and rebuild and modify it for higher voltages.  2) Buy a new motor build for use in an EV.  I chose to go with a new Warp9 from NetGain motors.  The Warp9 can match the performance of the stock Audi 1.8l turbo motor and they have a reputation for a good solid product that they sand behind..  I thought about the Warp11 for even better performance, in the end the 9 should give me plenty of performance and will fit without modifying the frame of the car. 

Batteries:  First I will say, “Lead is dead”.  To make a viable electric car Lithium batteries are required.  There are several different types of Lithium batteries that each has a different set of benefits and limitations.  After looking at some of the batteries I decided on the new CALB CA180FI cells.  I will be running 50 of these 3.2 volt cells to give about 160 volt and 28.8KW.  That should give me 100 miles range with a reserve. 

I decided to save on shipping and take a road trip with my son Max down to visit Jack and Brian at EVTV.  They are now selling the Calb Gray cells.  They happened to be getting ready to film their show and asked me to join them.  There must be something wrong with there camera, it makes me look like I have not hair.

It was a lot of fun taking a drive in their red Speedster replica.  It was a short drive do to a thunderstorm rolling in, but in the 10 minutes there were 3 people who honked and gave a thumbs up to the car. They were not even aware that it was electric, the shape of the car just attract attention.  The power of the car was amazing and the only sound was a few rattles from various parts of the car.  I can't wait to get the TT on the road.


After loading the mini-van down with batteries we headed back to Iowa.  Having 600 lbs of batteries in the back of the van got me a little concerned.  The load leveling system helped but we could still tell we had extra weight on board.  I'm sure I will end up making changes to the TT springs to be able to support the extra weight.

After unloading the 50 batteries, I took a picture and put them away for safe keeping.  After seeing the video of what happens to a wrench being shorted across these sells, I don't want to dropped anything across them.

While I was gone I got the "triple square" tools required to pull the pressure plate and fly wheel.  Bad news, when I got the clutch out it showed signs of lots of heat and abuse.  It will have to be replaced, good news is that a performance clutch is about the same price as stock so I will be getting an upgrade.


I also pushed the car out side and went through a bottle of heavy duty de-greaser cleaning the engine compartment.  I hope to stay a little cleaner while working on the car going forward.  

Since I didn't have parts to start putting anything together, I decided to break into the wiring harness for the gas engine.  There was one wiring bundle that went from the ECU to most of the engine electronics and sensors.  After removing things like the injectors, coil packs and knock sensors there was not much left.  I decided to leave the throttle body electronics intact for now.  I have not decided if I want to try to keep the ECU happy so I can pick the throttle position sensor from the throttle body to keep the cruse control working.  Seems like a lot of extra work for something that  is not going to get used in a vehicular that has a 100 mile range.  But it stays for now.  


I have the other half of the ECU wiring harness out of the car but ran out of time to dig into it.  This half is what goes between the ECU and the dash.  Looking at the wiring diagrams in the Bentley manual for the TT, I see lots of individual signals but no CAN bus yet.  Gives me hope that I may be able to get rid of most of the faults on the dash.  But that is for later.  


Next week I hope to get the motor mounted to the transmission and the motor mount made.  Once the motor is in I will start on battery boxes.

Getting the Engine Out

First step in pulling the motor was removing the front of the car.  It is much easier than what I was thinking, it is really the first step whenever there is work needing to be done on the TT's engine.

 

Once the radiator and other front parts are removed there were a bunch of wires to disconnect and label.  Most will not be reused with the electric motor but I didn't want to start cutting as I was not sure what would be reused at this point.  The way all the wires snake around made it fairly easy to disconnect and peel back the wiring harness.  Takes a lot of time to disconnect everything that the computer monitors to keep this engine running.

With all the wires out of the way there was very little left to pull the motor.  I did some measuring and found that the center of the crank shaft is 10" below the front engine mount.  I plan to reuse the engine mount with some modification, so I will be able to use this measurement to make sure the new motor is correctly line up with the transmission.

It was tight and I had to pull the power steering pump, Air Conditioner Compressor and the front engine mount to be able to get enough room for the transmission shaft to be removed from the clutch.  Looking back it would have been easier to pull the motor and transmitting at the same time.  If I had to put this engine back in I don't think it would be posible to get it back in this way. 

The advantage of doing it this way was after getting the engine out of the way I was able to measure the available length I would have for a motor.  The space between the transmission and the opposite frame rail is 19 1/2 inches.  I started to worry because I was remembering that the Warp9 that I plan to use has a length of 20 inches.

I had to go back to the Warp9 drawing and found that the over all length is 20" but the case is 16".  The motor shaft is not an issues since the 10" below the motor mount puts it below the frame rail.  Doing research I found that the 1.8l turbo that TT uses is the same as the engine in "New" VW Beetle from the same time frame.  This means that there is are adaptor plates available to mate the Warp9 to the transmission and I will not have to have one custom made.  

After emailing Randy at Canadian Electric Vehicles I found their New Beetle adaptor is 1.5" thick which will allow the Warp9 motor into the TT without modifying the frame.  



The adaptor is designed to reuse the fly wheel, clutch and pressure plate.  This is where I ran into a problem, the bolts used to attach the pressure plate and fly wheel use a unique "triple square" drive.  I had to order the tools before I can move forward.  More to come when I get tools in..

Tear Down Begins

Started the tear down process this weekend with a trip in 100 degree heat to a local auto service station to have the refrigerant sucked out of the air conditioning system to stay legal when I get to pulling that part of the car apart. The service tech could not understand why someone would their working system disabled in this heat.

 I got the car home and up on jack stands to start pulling parts. My plan was to pull the fuel tank first but I found that the exhaust system was in the way so it had to go first. Nothing a little time with an impact gun and cut off grinder could not take care of. I thought I was going to be able to remove the gas tank in one piece but the size of the filler neck made that impossible without removing the entire rear suspension. So I made the cut and turned the tank into junk, not that the fuel tank for a Audi TT is in high demand. By the end of the weekend the pile of parts that will never go back on this TT is growing.

 The area vacated by the fuel tank an exhaust will be filled by part of the battery pack. However, looking at the uni body structure there will be less space for batteries where the rear seat was that I was hopping for.

With the gas tank and heat shields removed, the under side is looking clean.

If I have to I can always remove the spare time to make more room for batteries, but I will have to make sure I have AAA coverage or someone at home to bring me my spare.

Next step is getting to the engine and start thinking about ordering some parts.  I hope to make progress more this week.

Why?

Why build an electric car?  I want to build an electric car mainly to prove to myself that I can do it.  I’m not out to save the planet, although I don’t like the idea of spending $ on oil that get sent off to people to want to destroy our country.  I also want to show other people that an electric car can be practical as a daily driver in Cedar Rapids, IA.  For more information on Electric Vehicles I recommend Jack and Brian’s EVTV videos at: EVTV

Why not by a Chevy Volt, Nissan Leaf or Tesla?   First, the Volt is not an electric car.  You don’t have to put gas in an electric car but the Volt will not run without gas in the tank.  The Volt and Leaf are both a little to econ-o-box for my liking.  The original Tesla roadster is a little smaller than I would like and it is kind of high dollar for a hobby.  I really like the Tesla model S and I think it is going to be a great car and may even turn the public perception of how practical an electric car can be.  That said I’m looking for a hobby to give me something to tinker with.

Why convert a 2000 Audi TT?  I’m decided on the Audi TT because I like the car, I didn’t want to put a lot of money and effort into a car that I really didn’t like.  It is small, light and is reasonably efficient.   The back seat is useless with a normal size person in the front seat there is no room for feet on the floor and the slop of the roof does not provide head room for anyone over 5’4” tall.  So this space can be used for a battery pack.   I chose a non-quarto TT for simplicity, basically the FWD TT is the same drive train as the “new” VW Beetle so conversion parts such as adaptor should be easier to come by without custom machining. 

Why start a Blog about the project?  I have never done a Blog so kind of a learning experience and I wanted to let family and friends know what I was doing.  I also wanted to show the process in the event that anyone is thinking about converting and Audi TT, maybe they can learn from my mistakes and made a better one than I could.