Porsche 914 EV Conversion

AUGUST 30, 2007

These last few days have packed with non-EV stuff, but I did take the DC-DC controller into the lab to see what was going on. First of all, there are no kick-back diodes on the inductors inside the converter. This kinda scares me since pulling on an inductor with a FET and then letting it go tends to create really high voltages (> 600V etc.). I hacked together a 160V DC power source by simply tapping off the bulk capacitor inside one of our power supplies.

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DC Convert Supplies Volt 100

Plug In Partners

AUGUST 30, 2007

I f there is any doubt that GM is serious about PHEVs, here is one more story that indicates that they are indeed very serious. GM Could Reportedly Produce 60,000 Plug-in Hybrids in 2010 Source: GreenBiz.com by Jeff Green at Bloomberg OAKLAND, Calif., Aug. 23, 2007 -- General Motors Corp. could reportedly produce up to 60,000 Volt electric cars in 2010 , its first anticipated year on the market.

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Volt Prius Oakland Alternative Fuels 100

Plugs and Cars

AUGUST 19, 2007

The Ugly Coal sucks, there's really no two ways about it. Extracting it is ruinous of the landscape and burning it has disastrous environmental consequences. It should be perhaps our last fuel of choice regardless of how it's used. But not all use of coal is alike. The Good About half our electricity comes from coal, and that will change, at best, slowly as we move to renewables.

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Coal Costa Rica Gasoline-Electric Cars 100

Porsche 914 EV Conversion

AUGUST 26, 2007

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. It seems to measure pack voltage well; however, the voltage measurement on each battery seems to be slightly inaccurate. The Zivan charger is balancing the batteries well and each of them is within an 8.48V-8.50V range (20mv difference is pretty good!).

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DC Convert Volt Plug-in 100

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Porsche 914 EV Conversion

AUGUST 24, 2007

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. Since the DC-DC converter was blown and I didn't want to deal with it, I focussed on some other electrical problems I'd been having.

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Volt DC Light Electric 100

Porsche 914 EV Conversion

AUGUST 24, 2007

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. The company that makes the DC-DC converter is CC-Power in the UK, so I don't think sending it back to them would be timely either. Here's the DC-DC converter taken out of its black aluminum case.

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DC Convert Volt IDEA 100

Porsche 914 EV Conversion

AUGUST 23, 2007

While cruising over to my girlfriend's house this evening, the whole system just shut down on the road. That was a rather scary experience. The hazard signals started flickering and nothing would turn on. After pulling over and checking the voltage on everything, the pack was nicely up at 150V but the accessory battery was down to 10.5 volts. With the key on, the DC-DC converter light was on; however, when I checked the DC-DC fuse, it was blown.

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Batteries Battery DC Volt 100

Porsche 914 EV Conversion

AUGUST 24, 2007

Before the accessory battery discharge yesterday, I wrote down a list of things to keep in the EV in case there was a breakdown out on the road. I came up with the following items. Any comments for additions or modifications would be welcome. Emergency Equipment cable cutters small fire extinguisher (for electrical fires) Repair Tools Haynes manual for electrical diagrams digital multimeter wire crimper and extra pink,blue,yellow quick-connect crimps two battery wrenches wrapped in electrical ta

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DC Kits Convert Connect 100

Porsche 914 EV Conversion

AUGUST 24, 2007

Well, I ran out to Radio Shack this morning and got some more 5 amp fuses for the DC/DC converter. After plugging a fast-blow fuse in, powering up the car blows the fuse. I tried a slow-blow fuse and that went too. I then disconnected the 12V battery to see if that was causing a problem and it still blew a fuse. What's sort of interesting is that these glass fuses didn't just melt and break, they really vaporized and completely coated the inside of the fuse glass with metal bits.

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DC Convert Volt Plug-in 100

Porsche 914 EV Conversion

AUGUST 23, 2007

Despite the issues with the car, I've decided to start commuting 15 miles each way to work to see how the car does. By not revving the motor above 5000RPM, I can minimize the vibration problem. The batteries are starting to break in. I'm getting slightly more power on the freeway now and starting from a dead stop is acceptable. I've taken the 914 up to 70mph.

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Porsche 914 EV Conversion

AUGUST 17, 2007

In my frustration to take care of the vibrating of the motor/tranny, I unbolted the motor from the front engine mount and raised it up with a jack. The clearance above the motor is tight so you can't raise it too much. After revving up the motor, it still resonates at 5000 RPM which leads me to believe that there's an issue with the motor to transmission coupling.

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Motor Motors Motoring Engine 100

Porsche 914 EV Conversion

AUGUST 17, 2007

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. I did get up to 65 but kept my speed mostly at 50 to not pull too much current while breaking in the batteries. Here's the wait in line for the ticket office at Portland International Raceway.

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Portland Maintenance Honda Waste 100

Plugs and Cars

AUGUST 18, 2007

A few items before I head out to Black Rock City for two weeks. Out in the desert as part of Burning Man , our encampment, Snow Koan Solar, is setting up a solar photovoltaic EV Charging Station (at 7:30 and Desert) for electric scooters, golf carts, sofas and barstools. We'll also be taking Burning Man art projects off petroleum generators by switching them to solar electricity.

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Porsche 914 EV Conversion

AUGUST 17, 2007

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. I borrowed a precision dial gauge from a coworker and measured the wobble on the motor adapter.

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Plug In Partners

AUGUST 14, 2007

G enerally, when we talk about Plug Ins , we think about automobiles. And there has been some big news on that front in the last few weeks. Toyota has now moved to have a plug-in approved in Japan and will test them on California campuses. Meanwhile GM is actively moving forward on the Volt. But there are other embodiments of plug in technology. This one might become a real favorite.

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Plug-in Plug Petrol GM 100

Porsche 914 EV Conversion

AUGUST 12, 2007

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. This was originally just a human powered vehicle made in Belgium, but the owner added an electric motor to power the rear third wheel to get up the hills in Portland (of which there aren't many in Belgium).

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Portland Belgium Kits Neighborhood 100

Porsche 914 EV Conversion

AUGUST 9, 2007

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. Three extension battery monitors are in the other three bags. The serial cable in the lower left can hold 2MBytes of log data before dumping it down to a laptop.

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Batteries Battery Motor Motors 100

Porsche 914 EV Conversion

AUGUST 10, 2007

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. They basically said that they couldn't balance the flywheel because they couldn't attach their balancing machine to the small center hole. Many thanks to Alan at A&P Specialties (Audi and Porsche repair) for lending me a 1.7Liter 914 crankshaft so I could provide something for P.E.R. to balance.

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Portland Porsche Audi Motor 100

Porsche 914 EV Conversion

AUGUST 6, 2007

Things just keep getting better and better with this car. I did some experiments this morning with operating the transmission and found that my clutch wasn't fully disengaging. After adjusting the clutch to fully release this evening, the car shifts MUCH better and I don't grind gears anymore! What a relief! I also took this evening to finish up the wiring for the external charging outlet on the front fender of the car.

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Installation Portland Plug-in Charging 100

Porsche 914 EV Conversion

AUGUST 7, 2007

Over the past few days, I've gone through the four stages of acceptance regarding the rather noisy vibration that the car undergoes when I rev the motor above 3500 RPM. Denial: "My new electric car is wonderful and it doesn't really rattle above 3500 RPM." Anger: "Why the hell does my car vibrate and rattle about 3500 RPM???!! It's not supposed to do that!

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Porsche Installation Motor Motors 100

Plugs and Cars

AUGUST 6, 2007

Seventeen years ago GM could imagine, and then produce, an electric car. Check out this 13 minute GM video on the car that became the EV1. Commenting on its technological achievements, John Zwerner, GM Advanced Product Engineering, says "we wanted to drive a stake in the ground.as to what a contemporary produceable electric vehicle would look like and how it would perform if we were to build such a vehicle.

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Volt EV1 GM Personal 100

Porsche 914 EV Conversion

AUGUST 5, 2007

Since traffic is really light on Sunday morning, I drove to work (15 miles away) and back to see how the 914 would handle. Shifting was a real pain on city streets since the electric motor changes RPM very quickly during acceleration or regeneration. The RPM stays constant when I "coast" unlike a gasoline engine which tends to slowly drift back to "idle.

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Golf Cart Volt Mariner Porsche 100

Porsche 914 EV Conversion

AUGUST 3, 2007

My friend Pete dropped by for lunch today with his video camera and we captured a four-minute video of the electric car in action as well as a description of the various parts. This is rather unrefined, so enjoy.

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Parts Electric Cars Cars Electric 100

Porsche 914 EV Conversion

AUGUST 1, 2007

Well, today was a good day. I got word back from Azure Dynamics after they analyzed my acceleration logs and they pointed me to the EE2NoAccelBat variable. Mine was set to 136 volts. It turns out that if the voltage coming from my batteries fell into the 136 to 149 volt range (EE2NoAccelBat + EE2AccelRamp = 149), then the controller would linearly limit the power going into the motor down to zero when the voltage reached 136.

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Kits Volt Light Plug-in 100

Porsche 914 EV Conversion

AUGUST 8, 2007

In my eagerness to balance the flywheel, I unhooked all the mechanical and electrical cables from the motor/transmission assembly and lowered it onto a furniture dolly. Note that I still need to borrow the CV joint bolt remover from Craig at Camp914, so the assembly is just sitting on the floor right now. I'll try to describe the process in a little detail since Joe posted a comment a few hours ago asking for more pictures.

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