Porsche 914 EV Conversion

MARCH 21, 2008

I received a shipment of 3-watt LED lamps and a low-load flasher relay from superbrightleds.com yesterday. The bulb bases were the same, so replacing the bulbs was easy. I ordered the CF13GL-02 LED flasher relay, which is a plug-in replacement for the Porsche 914 relay and responds to the much lower current pulled by the LED lamps. After installing everything, I found out that the LED flasher was able to detect such a low bulb current, that it was stuck in the "on" mode (relay clicking) all the

Installation 100

Installation Light Porsche Plug-in 100

Porsche 914 EV Conversion

MARCH 6, 2008

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. This presents the dilemma of running down the 12V battery while the main pack is charging.

2000 100

2000 Miles Volt DC 100

Porsche 914 EV Conversion

MARCH 1, 2008

Many months ago, I installed a PakTrakr ( www.paktrakr.com ) to monitor the state of my batteries and it's been acting rather flakey. The PakTrakr consists of several serially connect "remotes" which drive a "display" unit in the driver compartment. The voltage displayed shows the pack voltage and is supposed to monitor the state of each battery and the State-Of-Charge (SOC) for the pack too.

Oregon 100

Oregon Connect Connected Kits 100

Porsche 914 EV Conversion

MARCH 1, 2008

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. It looks like each PakTrakr remote has three wires coming out of them: Black - zero volts from that module Red - 11-12 volts from that module Green - 3.3 volt signal that sends a pulse train every second (pulses to zero volts) The signal on the green wire had significant over and undershoot on it, so I thought of ways to t

Volt 100

Volt Green Clean Cleaning 100

Porsche 914 EV Conversion

FEBRUARY 23, 2008

I took the 914 back to A&P Specialties yesterday to upgrade the front brake calipers with ones from a BMW320i. The brake pedal definitely feels different. I can push it a lot farther towards the floor and the pads seem to bite quite a bit more. I hope this will help with any emergency braking I might have to do. Given the sluggish acceleration of the vehicle, I started looking into lighter batteries.

Lead Acid 100

Lead Acid Purchase Batteries Battery 100

Porsche 914 EV Conversion

FEBRUARY 24, 2008

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. I tried firing up the generator with a little gas and it didn't go into overload with the Zivan charger at the 60% (12 amp) setting.

Charging 100

Charging Honda Miles Purchase 100

Porsche 914 EV Conversion

FEBRUARY 12, 2008

I ran out to Barnes and Noble today and picked up the March issue of Sports Car Market magazine. My 914 was featured on page 38 along with John Benson's 914 DC conversion! I hope Electro Auto doesn't get even more swamped by the publicity. I'm glad these EVs are getting coverage so more people can see what's possible. For those of you who have converted your own 914 to electric, I encourage you to contribute to the Electric Conversion page of the 914 Wiki at RoadGlue.com: [link] I spent most of

DC 100

DC Conversion Oregon 2000 100

Porsche 914 EV Conversion

FEBRUARY 9, 2008

Many things have passed through my mind over the past year and a half while converting this vehicle. I'd like to capture some of the good and bad things to help keep other people from falling into the same holes as I did. Here goes (in no particular order): Things That Went Well During the Conversion The 914 AC kit from Electro Automotive is a good one.

Convert 100

Convert Kits Conversion DC 100

Porsche 914 EV Conversion

FEBRUARY 9, 2008

One of the annoying behaviors of the motor system in my AC 914 kit is that the default DMOC445 parameters causes the acceleration and braking to have oscillations. In physics speak, the application of the positive or negative torque happens so quickly that the system is underdamped. The step function of the torque perturbs the mass of the car and it oscillates for a bit before settling down, primarily in first gear where the motor has the most influence on the acceleration and deceleration of th

Neighborhood 100

Neighborhood Conversion Kits Convert 100

Porsche 914 EV Conversion

FEBRUARY 7, 2008

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. The wiring is a bit messy because I had to cut all the tie-wraps off from the original setup. I just wanted to try this out for awhile before taking the time to clean it up.

DC 100

DC Installation Parts Convert 100

Porsche 914 EV Conversion

FEBRUARY 8, 2008

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. I tried using an automatic battery filler from NAPA to fill the batteries, but the nozzle kept jamming and the weight of the water in the tank wore out my arm muscles.

Batteries 100

Batteries Battery Water Kits 100

Porsche 914 EV Conversion

FEBRUARY 6, 2008

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. I've been biting my nails over the past few weeks, living in fear that my 12V battery would suddenly run out on the freeway in the rain as I drove with my headlights on.

DC 100

DC Kits Convert Conversion 100

Porsche 914 EV Conversion

JANUARY 27, 2008

It's good to get the extra transmissions out of my garage. I guess it's poetic justice that the guy who bought my side shifter from the original car is going to give it to Jeff at Rothsport systems for a rebuild, the same guy who didn't work on it for 2 1/2 months when I gave it to him. The buyer of the tail shifter transmission is also in the process of doing an electric vehicle conversion, so he asked a bunch of questions about my project.

DC 100

DC Light Climate Recharge 100

Porsche 914 EV Conversion

JANUARY 25, 2008

I dropped off the 914 with Alan at A&P today to upgrade the brake cylinder and do a front end alignment. Brett, a local guy, is going to purchase my two leftover transmissions and Curt from Salem is visiting today to see the car (hopefully back from the shop). In the meantime, I took some approximate readings from my ammeter and voltmeter as I drove on flat roads this past week.

Miles 100

Miles Volt Purchase All-Electric 100

Porsche 914 EV Conversion

JANUARY 22, 2008

Today was the first day on the freeway with the new transmission. Other than watching my amperage, I didn't have any issues and the car drove just fine. Many thanks to all the people who have offered their support during this long wait to get a working transmission. I'm happy to see all the other 914 EVs out there. On Friday I'll be re-aligning the front end for better steering and replacing the brake cylinder.

Re-Charge 100

Re-Charge DC Purchase 2008 100

Porsche 914 EV Conversion

JANUARY 17, 2008

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. Here's Rick and Holly in the working vehicle. We drove the vehicle around the block and the transmission was very smooth.

Cars 100

Cars Vehicles 100

Porsche 914 EV Conversion

JANUARY 16, 2008

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. We were a bit nervous when we heard a minor squeal inside the transmission case. We then put the transmission into first gear, allowing the fresh transmission fluid to flow from the bottom shaft onto the gears on the top shaft.

Exhaust 100

Exhaust Light Motor Motors 100

Porsche 914 EV Conversion

JANUARY 15, 2008

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. The fiberglass straps are broken, the lid is totally cracked in pieces and most of the corners are dented in. Here's the transmission removed from the plastic tub in my front hallway with plastic peanuts everywhere.

Parts 100

Parts Clean Cleaning Motor 100

Porsche 914 EV Conversion

JANUARY 11, 2008

I just received an e-mail from Greg Robbins that he shipped a rebuilt transmission to me via UPS and it should arrive next Tuesday! The UPS tracking number concurs with this. This will be a good time to get back into the swing of things since my girlfriend Krista is starting classes next week and the holidays are winding down. Working in the garage is a bit slow since it's cold and rainy, but I should be able to get things put together.

Saturn 100

Saturn Gas-Electric Gasoline-Electric Wind 100

Porsche 914 EV Conversion

JANUARY 28, 2008

I lost much sleep last night obsessing about how I could fix the DC-DC converter and, as a result, I was very tired and had an irritable day. For those of you who have read my blog entries in the past, you know I've blown up the internal FETs of the DC-DC over five times and spent countless hours reverse-engineering the circuit with experts at work to see just what could possibly be wrong with the system.

Kits 100

Kits DC Google Convert 100