Zach’s Electric Diablo

I know it sounds like an excuse, but the house remodel is taking all my time.  Check out these videos:

I promise… one of these days I’ll make time to work on the car.

Today I transported my car (via trailer) to my house.  Now it should be much easier for me to find time to work on it.

It’s been a busy month and I haven’t had a single moment to work on the car.  I’ve got a couple more weeks of craziness and things should slow down enough to give me my weekly work session again.  After being a consultant for past few years, I finally decided to get a “real” job.  I’m now building underwater robots and submarines.  It’s really exciting to start working in a field that is so different from anything I’ve done before.   I’m learning how to make technology work in very harsh environments.  Some of these skills will definitely help in making the car more robust.

Lately, every time I work on my car, I forget to bring my camera.  So, there are no recent pictures. Sorry…

Even though I can’t prove it with pictures, I’ve been making some major steps the past few weeks.  The big one is that the body is now mounted.   YEAH!!!  It took eight tubes of 3m 5200 adhesive and a week to cure, but it is permanently on there.  I’ll try to remember the camera this weekend.

I’m now onto the daunting task of the doors.  They truly define that “Lamborghini style” and they need to work smoothly.  So, I am taking some extra time to plan my attack.  The doors end up weighing around 250Lbs and are supported by a single hinge just a few inches wide.   So, everything has to be very rigid.

My friend Vincent is a true professional when it comes to composites. He has been very helpful with all my bodywork and fiberglass questions (e.g. What’s the best way to bond X to Y?). When I told him my plan about bonding my shell to the chassis with urethane caulking, he had lots of suggestions. The first one was to use 3M 5200. It’s typically used for marine applications, but it is incredibly strong and stays flexible.

His next suggestion was to “bog” the mating surface between the shell and the chassis (I learned that in the fiberglass realm, the term “bog” refers to a resin filler that fills gaps between materials). We started out by using double sided tape as a spacer. Then we layered pieces of packing tape over the double sided tape. The double sided tape creates a space for the caulking, the packing tape helps release the bog.

We also used some “magic” mold release liquid on the packing tape as an extra layer of insurance.

After that, we glued some regular fiberglass mesh to the chassis using 3m 77 spray adhesive. Then we mixed up the bog. The bog was a mixture of two part fairing compound (similar to Bondo, but much better) and short fiberglass strands. This made the bog quite stiff and less likely to drip all over the place. We spread the bog onto the fiberglass mesh, then placed the shell onto the chassis. We clamped it in place to get everything level.

After 24 hours, we popped off the body. The bog stuck to the shell very nicely and released from the chassis with almost no effort. This is the result:

Now I just need to clean up the edges of the bog and then prep both surfaces for the 5200. Next week we should have the shell mounted.

The list of “stuff to do” before I put the body on is growing short.  Here’s what I got done this week:

I built some new brackets for the headlights. It’s now easy to adjust the position and angle of the lights.:

I installed the battery hold-downs.

I applied some bright orange tape to the high voltage lines.

I used some fairing compound on the area where the headliner will eventually go.  I want this to be nice and smooth.

I built some brackets for the AC condenser.

Stuff left to do before the body goes on permanently:

• Weld up some body mount brackets to support things like the rear quarter panels and other pieces of fiberglass not in direct contact with the chassis.
• Add some steel around each of the door/trunk latches.
• Add a support for the rear hood.
• Mount the motor controller radiator.
• Add some steel around each of the hinge locations for the trunk lids.

I’ve been working on my car almost everyday for the last three weeks. It has been great, I’ve gotten a ton of stuff done.

My roll cage/body mount needed to be tweaked in order to get everything lined up. This meant cutting it off and re-welding it. Now the body sits on the chassis squarely and the wheel wells line up with the wheels. While I was at it, I finished up welding the windshield columns and added some gussets to beef up the roll cage.

Long ago I cut out a large section of the center console. The chassis came with a center console that was extra large to make room for a large fuel tank. Seeing that I didn’t need a fuel tank, I decided to retake the space by cutting it out. Now I’ve re-welded a smaller center console and filled in all the holes.

I added connectors on the battery cables and the cables to the motor. This adds a level of safety when working around the high voltage. It also makes it very easy to remove all the high power electronics, just take apart a few connectors and all the high voltage electronics can be removed.

I started wiring the battery box for BMS v2. One wire to each battery.

I started preparing the body for mounting. Step one is to scrub off all the resin wax. I flipped the body over and scrubbed the heck out of it. Next I’ll be painting the underside black and mounting all the grills. Then I can glue it to the chassis.

Here’s some other misc. stuff I did, but didn’t take pictures of:

- Cut out a safety cover for the batteries.

- Fabricated a safety cover for all the high voltage electronics. I used 1/8 polycarb bent in a sheetmetal break. Polycarb is great as is bends just like metal.

- Discovered that my air lift system kind of sucks. To install it, I would need to modify the chassis a bit. Plus in the best case it would raise the nose by 2″. I think I might ditch it and just put rollers under the front nose.

- Solved the problem with the vacuum brake booster. I figured out that one of the ports on the reservoir had a built in one-way valve, and I had the tubes on backwards.

- I modified the battery box to accommodate some better battery hold downs.

Now that the high voltage electrical is starting to look good, I figured it was time to start cleaning up the 12 volt side of things.  I made a fuse/relay board to mount everything to:

The weather has finally started to change and today was the first day I need to move my car while it was raining (there is a short drive from my storage container to the shop). I didn’t want my electronics to get wet so I used a little shrink wrap to make a windshield and trunk lid:

It may not look so in the picture, but my shrink wrap windshield is quite easy to see through.

All the high voltage electronics are now neatly mounted on the rear tray.  In the process of remounting everything, I removed a lot of excess wire  to clean everything up:

My goal is to make the tray removable to enable easy access to all the electronics.  To make this work, I need to “connectorize” the pack, the motor and all the low voltage control lines.  My plan is to get two beefy Anderson connectors (one for the battery pack and one for the motor) and some kind of multiconductor bayonet connector for all the low voltage lines…

Here’s a couple pictures I took a while back, but didn’t include in previous posts.

This is a shot of the roll cage/body mount:

As you can see, I still need to weld the last piece to attach the windshield pillars to the chassis.

Here’s a shot of my LED tail lights:

It’s been two weeks since I have posted an update so there is lots of progress to report.

1. The BMS version two is up and running with a single MAX6802 (I should be getting some more chips any day now). There is just one bug I need to figure out. The last battery in the chain is reading 0 volts. All the others read fine. This could be because it is supposed to be wired up to the next string which isn’t installed yet. However, I think there might be something else going on. We’ll see…

2. I welded up a new aluminum mounting bracket for all the high voltage electronics.

This tray will be the final mounting location for everything that uses full pack voltage; motor controller, charger, etc… It will be accessed from the rear hatch:

3. I remounted and started the process of re-wiring all of the high voltage electronics. I am mounting everything to a piece of polycarbonate which then bolts to the aluminum bracket I made.

4. I installed my new 500amp 50mV shunt. This should give me better readings than the previous 1200amp 50mV shunt.

5. I received and tested all the LED lighting for the car. These will replace the standard incandescent backup lights, turn signals, brake lights, and side markers.

6. I cut out the safety cover for the battery box.  It is 1/4″ polycarbonate.  Later I will figure out the best way to vent it.