Zach’s Electric Diablo

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.

After some jumper settings and a secret configuration menu, my Mac Mini and Lilliput screen come on when I start the car and automatically shutdown (cleanly) when I turn off the key. The main trick was to use a “smart” power supply. The one I used was a Carnetix CNX-P1900. It takes in 12v and a signal from the ignition switch. It outputs 18v for the Mini and has a controlled 12v output to power the screen. It has a special plug which attaches to the Mini’s motherboard and lets the power supply virtually press the power button on the Mini. It is fun to turn the key and hear the Mac bootup sound (even though it boots to windows XP).

My seat is now bolted to the floor and the racing harness is installed.

I also installed the Mac mini, 12v power supply and an LCD screen (the LCD mount is temporary until I mount the dash). This setup will be helpful during testing to display battery status and speed information.

Now that I am starting to accumulate the 12v devices, I thought it was about time to officially wire up the DC to DC converter. It takes the pack voltage and charges the 12v lead acid accessory battery.

My Dad came into town for a few days and Saturday morning was our time to work on the car. He helped me install the repaired axle and the new spacers I made. Everything fit perfectly. Then we took it down to Big-O to get it aligned. After about an hour of working on it, the guy got it “mostly” aligned. Apparently, my rear a-arms don’t have the proper geometry to get it 100% aligned properly. I’ll go into more details about this later.

When we got back to the shop we took it out for a spin. I don’t have a speedometer yet, but we must have got it up to 50-60mph in and around the parking lot. It felt REALLY good. It accelerated very quickly and handled quite nicely (though, I don’t have seatbelts and my batteries are not 100% strapped in so I didn’t push it too hard). I’ll get some video on Monday.

The mail man dropped off my BMS printed circuit boards yesterday.

I did a quick test fit to make sure they fit on my batteries:

I first built one, and tested it:

It worked perfectly. Here are the features it has:

1. Measures battery voltage
2. Measures temperature
3. Has a 3W 10 ohm resistor that can be programmed to shunt excess current during a charge cycle (balances the cells)
4. Talks over an opto-isolated serial bus.
5. Has a programmable RGB LED (used as a diagnostic tool and for adding some “coolness” to an otherwise boring battery pack)

Then I built 10. (This took about two hours)

Only 40 more to go…

Some friends came by the shop to check out the project. My friend Michael shot this video…

For some reason I have been waking up very early this week. Yesterday was 6am, today was 5am. The nice part about this is I can leave my house early enough to beat all the traffic and still have time to do a little work on my car before I need to start my “real” job.

Yesterday, I spent some time diagnosing brake noise. Today, I replaced the shifter from ASCC with one from http://www.brandwoodcarsllc.com. It works SO much better. I can actually shift into 5th gear!

On Sunday, I had a chance to work on mounting my seat shells (they will eventually be upholstered and become “real” seats).  I bought by seat rails from cip1.com

I bent up some brackets to set the seats at the correct angle (well at least what felt correct).

I also welded a cross-bar on to give it added strength.

Now I just need to mount them to the chassis…

I finished up all the hard brake lines last night. The braided lines will get installed when I install the calipers. However, I can’t install the calipers until I get new wheels (the little donut tires don’t provide enough clearance). I’ve been searching for a good deal on wheels, but haven’t found anything yet.

So, I am “shifting gears” and getting ready to dig into motor/transmission mounting. I ordered a clutch kit for my transmission and started doing research on adapter plates. I am really glad I have access to a good machine shop…