Porsche 914 EV Conversion

Wiring and Rewiring - Getting Close!

Porsche 914 EV Conversion

Ugh, I'm dehydrated, exhausted and mad at this inanimate object. I must love doing this conversion. There's a fine line between a hobby and insanity) Tonight was spent attaching all the copper bars to the battery terminals.

2007 11

Saying Goodbye to my 2007 Dream Project

Porsche 914 EV Conversion

I contacted someone who expressed interest in purchasing the 914 a few months ago and that contact came through for me. Here's my parting shot with Dan, the new 914 EV owner. Dan has worked with a Bradley GT EV before, so he knows the ropes.

Trending Sources

Time to sell the 914

Porsche 914 EV Conversion

It's time to sell the electric 914. It's been a fun road, but I have three cars now (as a single guy) and only a 1-car garage in the middle of the city. The car has been good to me and made the electric Civic project go so much faster.

Bypassing theCharger

Porsche 914 EV Conversion

Since my battery voltage never gets above the cutoff point for the Zivan charger bulk phase, I made a special charging cord with a timer built into it. If I leave the Zivan in low-current mode, I only pull 12 amps, which is less than the 15 amp rating of the timer.

Fixing the Aux Battery Killer

Porsche 914 EV Conversion

I took the time today to research the 914 wiring diagrams and find the annoying connection that leaves my tail light on after I turn off the ignition switch. If you remove the front dashboard cover and look under the steering column, you should see two connectors. Remove the right one as shown above.

2000 miles and counting

Porsche 914 EV Conversion

I broke 2000 miles with the 914 EV this week. The car has been running smoothly with no complaints. One of the "features" of the 914 is that the turn signals come on (but don't flash) if you leave the turn lever in the "left" or "right" position, even when the ignition is turned off.

Fixing PakTrakr Signal Integrity

Porsche 914 EV Conversion

Well, I played around tonight and looked at some of the PakTrakr signals on the oscilloscope and found some noise on the data line going between the PakTrakr "remote" modules.

Charging Up on Roadtrips

Porsche 914 EV Conversion

I'm considering taking the car on some slightly longer journeys this summer and don't want to be caught out in the middle of nowhere with a dead battery, so I ran out and purchased a Honda generator that can charge the car for four hours to get a few more miles out of it, if necessary.

New Tranny Fluid, Battery Filler and EV Toolbox

Porsche 914 EV Conversion

I tied up a bunch of loose ends today on the 914EV. I replaced the transmission fluid with the synthetic Royal Purple fluid from ElectroAuto. The transmission seems to spin more quickly and run quieter, but that is a highly subjective assessment. I'll know more by the end of next week.

DC-DC Installed and New Brake Parts

Porsche 914 EV Conversion

In was eager to get the new DC-DC converter installed so I left work a bit early and got to work so I could still drive the car to breakfast with my girlfriend tomorrow morning. Here's the mostly final installation.

New DC-DC here and Tranny Fluid Too

Porsche 914 EV Conversion

I let out a major sigh of relief today when the new Iota DC-DC converter showed up today along with the synthetic transmission fluid that ElectroAuto said they would send me. I'll start the installation tomorrow after finishing my third week of commuting to work.

Up and Running Again!

Porsche 914 EV Conversion

My friend Rick and his girlfriend Holly were gracious enough to come over and help me finish putting the transmission back into the car. We worked from 7pm-10:30pm and finished the job. Here's Rick and I under the car re-attaching the CV joints and getting covered with grease.

Yay! Less Vibration!

Porsche 914 EV Conversion

Rather serendipitously, my friend Jonathan dropped by this evening and we joined the transmission to the electric motor and spun it up. I was quite relieved that spinning up the new transmission to 5400 RPM produced little, if no vibration.

New Tranny Here - Salvaging Cracked Parts

Porsche 914 EV Conversion

The newly rebuilt transmission from Greg Robbins showed up via UPS today at 95 pounds. Here is the plastic tub that it was shipped in. The tub doesn't look like UPS treated it very well. Another view of the tub.

Update to Azure Dynamics DMOC Information

Porsche 914 EV Conversion

I've been receiving several requests this past year for the FTP site that contains the information on the Azure Dynamic DMOC445 controller. I just received word from Azure Dynamics that they posted all this relevant information online here: [link] drive/TractionMotorswithDigitalMotorControllers.htm Have a great Holiday Season! Cheers, Tim

Hair Dryers Installed

Porsche 914 EV Conversion

I took a few hours today to get the small hairdryers installed. In order to have a convenient switch to activate the hairdryers, I hijacked the defroster knob switch. I was lucky enough to have this option on my car.

DC 2

Serial Port and Hood Pin

Porsche 914 EV Conversion

Today was a bit slow. I received some AMP pins in the mail that fit the special connectors on the DMOC445 controller. To make the serial port more robust, I crimped the pins onto the ends of the 16-gauge wires and inserted them into the 8-position connector that came with the DMOC.

Dedicated Charging Outlet and Hairdryer Coupling

Porsche 914 EV Conversion

After sleeping for 14 hours last night, I think I'm somewhat recovered from that nasty cold. I dropped by Parkrose hardware after work and picked up some stuff to install in the EV.

Initial Fuel Gauge Driver Schematic

Porsche 914 EV Conversion

Since I'm stuck indoors today to recover from a sore throat, I put together the following schematic to drive the fuel gauge based on the pack voltage. Click to enlarge the image) With the exception of the 4N25 opto-isolator, which I salvaged from a dead UPS, all parts are available at Radio Shack.

Finishing the Rain Gutter for the Engine Compartment

Porsche 914 EV Conversion

The major project of the day was finishing the rain gutter under the engine compartment lid. The original gutter was too deep and interfered with the rear battery box. As described in a previous post, I purchased a piece of ABS plastic from TAP plastics and bent the edges to make a rain catch.

Finishing the Serial Cable and Testing the Fuel Gauge

Porsche 914 EV Conversion

I had a bit more time today to work on some other small projects. Here's the 914 patiently waiting for its rebuilt transmission from Rennsport Systems. It'll be awhile since Rennsport won't start on the rebuild until November.

Getting the Tachometer and Lights Working

Porsche 914 EV Conversion

After receiving an updated.css file (ccShell config file) from Azure Dynamics for the DMOC445, I was able to access the EE1SpeedoDiv variable. After setting this to a non-zero value, I attached a scope to pin 25 of the main DMOC connector and (yay!)

Replacing the Pilot Bearing

Porsche 914 EV Conversion

I purchased a new pilot bearing for the flywheel to see if replacing it would help with the rattles. Flywheel - it's what's for dinner!

Trying a Different Transmission

Porsche 914 EV Conversion

Last week Craig at Camp914 offered to lend me another transmission to see if I had vibrational issues. I drove out to Camp914 this morning. I wish to express much gratitude to Craig for letting me borrow this spare tranny.

Hub is back but EE1SpeedoDiv is not there

Porsche 914 EV Conversion

Today had some ups and downs. I got the adapter hub from Electro Automotive back today. I installed it on the motor shaft and, to my delight, it had less than 1 mil of runout and wobble! That's how the hub is supposed to work.

Getting the Heater Relay and Sending Back the Hub

Porsche 914 EV Conversion

After putting the adapter hub from Electro Auto onto the motor shaft no less than twenty times, I'm pooped. I tried filing down several different faces of the hub to get the runout and wobble down and failed. It's going back to EA tomorrow morning for a new one.

DC 2

Keeping the Rain Out

Porsche 914 EV Conversion

Since I live in the Pacific Northwest, I get rather concerned that rain entering the engine compartment will cause problems with the electrical wiring. Many other 914 EV'ers have protected their wiring inside conduit boxes and other shields.

Those (Not So) Good Vibrations

Porsche 914 EV Conversion

Well, it's time to bite the bullet again and see what I can do about the car vibrations. My friend graciously helped me remove the motor/tranny from the car again this morning and assisted with crude vibration measurements.

DCDC Transistor Hack

Porsche 914 EV Conversion

After talking with various people and realizing that the over-current circuitry was making the FET gate pulses way too large, I decided to hack the DC-DC converter circuit. Here's the new circuit (click to enlarge).

DC 2

Debugging the DC-DC waveforms

Porsche 914 EV Conversion

I spent most of Friday trying to figure out just what was blowing the DC-DC converter. Here's my full testbench setup. On the upper left, I have a 156V DC power supply. On the lower-left sits a 12V battery to act as an accessory battery. The 30Mhz $400 oscilloscope sits ready.

I Blew it Again! Learning About Soft-Start.

Porsche 914 EV Conversion

After studying the oscilloscope waveforms, I believed that the current sense circuit was way too spikey. This is the "amp adjust" potentiometer output in the C400 schematic.

DC 2

Initial CCPower Schematic

Porsche 914 EV Conversion

In my efforts to debug the failures of the DC-DC converter, I tried to capture a schematic of the board. I didn't have time to create a component for the SG3525A controller, but all the pin numbers are listed.

DC 2

PakTrakr is Online! DC-DC blown again.

Porsche 914 EV Conversion

I spent most of yesterday and a few hours today wiring up the PakTrakr system. It's a bit of a pain to disconnect the most negative lead before attaching the display, but that's minor nuisance.

Getting the EV Back to the Shop and Fixing Electrical Stuff

Porsche 914 EV Conversion

Just before noon, I drove with the ICE vehicle over to the 914, charged the accessory battery with jumper cables for about 20 minutes, then quickly drove the 914 back home to the garage for repairs. Since the stranded EV was only 2 1/2 miles away, I walked back to the ICE car and drove it home too.

Fixing the DC-DC Converter

Porsche 914 EV Conversion

I cringe at the thought of having to send anything back to Electro Automotive for replacement or repair, so I took a chance and dissected the DC-DC converter to see if I could fix it.

Fixing the Flywheel - Still Vibrations!

Porsche 914 EV Conversion

This has been one heck of a week. I took the flywheel into an automotive machine shop to balance along with the attached clutch assembly. In the meantime, I tried to figure out if the real problem was the motor to flywheel adapter from Electro Automotive.

NEDRA Pictures

Porsche 914 EV Conversion

Going to NEDRA at Portland International Raceway was my first major excursion in the 914 since both the flywheel was balanced and the clutch was properly adjusted. The car handled very well and cruised on the freeway without much problem.

Taking a Day off to see the EV Show

Porsche 914 EV Conversion

I took the day off to walk around Portland to the farmers market and EV awareness day with Krista. There were probably twenty electric vehicles at EV awareness day. Here are just a few of the more notable ones. The electrically augmented bicycle.

Balancing the Flywheel/Clutch

Porsche 914 EV Conversion

Okay, since I take Fridays off, this gives me a chance to take the flywheel into a machine shop for balancing. I took the flywheel and clutch pressure plate to Portland Engine Rebuilders.

PakTrakr Arrives and Adapter Misaligned

Porsche 914 EV Conversion

Well, this day definitely had its ups and downs. The PakTrakr battery monitoring system I was expecting early next week actually showed up today. Here's the PakTrakr still in all its bags. The main display and one battery monitor unit is in the upper-left bag.