|Owner's Other EVs||2009 Epic Electric Lawn Mower|
2011 Nissan LEAF
|Location||Canton, Georgia US map|
|Vehicle||1974 Porsche 914 |
All electric Sports Car made with an Electro Automotive Kit. I found this truly zero rust Karmann body in Arizona. The chassis grew up in California. This is a home conversion using the well-engineered Electro Automotive AC VoltsPorsche kit. A successful EV and my daily driver. To see a video of the car go to WebPage
|Motor||Azure Dynamics/Solectria AC24 3-Phase AC|
A perfect combination. At about 6 continuous horsepower per thousand pounds of vehicle, its at the low end of roadable performance and at the high end of range for typical home conversions. Its a great little car!
|Drivetrain||Azure Dynamics AC24 motor bolted to factory 5 speed through a stock clutch and a very nice Electro Automotive adapter. Synthetic lube in the gearbox (a little slippery for the synchros but great for friction) and the regen tugging the motor speed down require shifting be done more carefully. I doubt that a clutchless design would work well in this car. The clutch only is necessary for shifting at speed. Most of my downshifts occur at stopsigns and are clutchless.|
|Controller||Azure Dynamics/Solectria DMOC 445|
three phase inverter with clever computer functions to care for almost everything! Parameters can be recalibrated and diagnostics can be captured with a laptop computer in the privacy of your own home.
|Batteries||18 US Battery 8VGCHC with small L posts, 183 amp-hr, need replac, 8.00 Volt, Lead-Acid, Flooded|
Nice quick release caps on most cells, as the flat copper interconnects allow. Now batteries are down to under 2.1 volts per cell so range is less, but it's slow around town. I'll leave the installation of the next traction pack to the new owner so that any battery warranty issues will be simplified. (An experienced builder might even switch this car over to lithium batteries; there's certainly enough room for a big set. Motor/controller can be programmed to higher voltage and the charger can be modified at the dealer.)
|System Voltage||144 Volts|
|Charger||Zivan NG3-120VAC input|
Has a temperature probe in the battery box to monitor charging. Takes a long time to charge, but I like to take a long time to sleep too. I think the batteries probably enjoy the leisurely charge. The beauty of the 120 VAC charger is that it can be charged from most any home. (240 VAC chargers are nearly twice as fast but have much more limited sources and can have plug compatibility problems.)
|Heater||Ceramic heater with three speed fan from CanEV. I think it would be warmer with a higher voltage traction pack, but it's primary function is defrost so it should do fine. I purchased a 914 speaker box made to look like the factory console (on eBay). The warm air goes up the right side heater duct and wyes into both sides of the factory heat distribution system.|
|DC/DC Converter||Zivan 96 to 168 volts, newly installed 10-3-2008|
I had a CC Power unit for a 144v pack. It got sick; EA said was from regen voltage spikes. EA sent me a new Zivan DC/DC. I limited the high voltage spikes by programming a lower regen voltage limit in the DMOC. The new Zivan performs well.
|Instrumentation||From the kit I installed State of Charge (just a voltmeter with zero to one hundred instead of voltage numbers) and +/- Ammeter on left windshield pillar. The pillar is a great place for these important gauges. The stock VDO tachometer reads motor speed from DMOC controller, pin 25. Having the tachometer is extremely helpful in driving and particularly shifting. The voltmeter billed as a state of charge meter leaves alot to be desired. I finally added voltage numbers to the alleged state of charge meter -- much better! A real SOC would be a better setup. My odometer is my best SOC meter now that I have experience with the EV, just like the trip odometer in my ICE is better than the fuel gauge. I also added a VDO low voltage voltmeter to monitor the 12 volt system and the DC/DC converter. Its mounted in the center console which also houses the electric heater.|
|Top Speed||70 MPH (112 KPH)|
100 mph is estimated by Electro Automotive. The car is geared for about 100 mph, but I haven't done more than legal expressway speeds. I'd have to program the power from 29kW to around 36kW to get more than 70, I suspect. Even then, freeway speeds are best kept to a modest level. I'm happy with freeway speed for an ocassional interstate trip at 60mph. I can see 80 mph on the down hills, readying for the next up hill, when driving aggressively. Freeway speeds eat about double the amps so halve the range. It's surely better than an NEV!
|Acceleration||Acceleration is reasonable for me. (It won't touch Otmar's; maybe like my old 1963 VW beetle.) Zero to 30 mph is a leisurely 12 seconds all in 2nd gear. (I use first gear just to leap into traffic at busy intersections, but I use second gear all around town -- drives like an automatic.) I consider this very usable performance. Zero to 60 takes longer because accleration drops off above 40mph. This probably irritates a few driver's of big SUVs who have no concerns about fuel efficiency. One can start more quickly using the clutch and a few extra revs, but why wear things out faster? I started with all three power levels set to 29kWatts. Now I'm experimenting with switchable power maximums. The switch is labeled "turbo". (The AC24 motor is rated to 43 kWatts at 156 volts, about 36 kW at my 144 volts.) The DC amperage pegs the 200 amp gauge at full throttle. (It is important to program the DMOC for your needs with a laptop and the ccShell program available from AzureDynamics. Be sure to buy the connecting cable.)|
|Range||125 Miles (201 Kilometers)|
estimated by Electro Automotive. I haven't measured it yet in the real world, but the EA estimate is only for favorable conditions, probably like 30mph on level road with no stopping. I suspect super range would be obtained with the original low power setting of about 11kWatts. I tried that and it was not as fun to drive. So far, 35 mile trip around town hardly makes any movement in the state-of-charge (read that numberless voltmeter) gauge. My monthly 52 mile jaunt on the interstate will drop the pack voltage to 140v. The DMOC is programmed to shut off acceleration at 126 volts to protect the pack. Really fast highway or very hilly driving probably has a 70 to 90 mile range, but why push it? I intend to keep my batteries happy for a long time.
|Watt Hours/Mile||Looks like a little less than 300Whr/mile @ 50mph. Hard to get a steady amp reading because I haven't found a flat road around here.|
|Seating Capacity||2 adults, one adult and one Dutch Shepherd, or one adult and groceries; its a small car but fits my 6' 1" just fine. Ingress/egress is hard because it's low to the ground. There is some trunk space around the DMOC inverter/controller in the rear compartment for extra dog food.|
|Curb Weight||3,000 Pounds (1,363 Kilograms)|
This is a guess. It started at 2129 pounds according to the factory. I have not weighed it. The additional weight is felt in driving on a bumpy road, but with Regen braking, the weight is hardly noticeable in stopping. It's a squeaky old convertible that still turns heads. Most people seem to think its a new car, not a 35 year old classic.
|Tires||Kumho Power Star 758 in size 165/80-15, new on 5-22-2009 These were the closest I could get to original size so speedo is more accurate. They give me an honest 42 mph in 2nd gear where I like to drive around town. Better at keeping up with traffic without a lot of shifting. I'm using 40 psi for rolling resistance; ride's not too harsh. The steering wheel is not perfectly centered because one tie rod is slightly bent. Been that way since I purchased the car. I suppose it ought to be changed, some day.|
|Conversion Time||Took about a year to get it driving (mainly waiting for parts); but except for the traction pack, it's pretty well debugged after a couple years of daily driving.|
|Conversion Cost||about $22K above the cost of the car and a lot of sweat equity, but worth it! |
The kit alone is now up to $14,635 with about a thousand in shipping. (Battery boxes and frames are nearly $2500 by themselves, but super nice.) Not to mention typical restoration: new wheel bearings, ball joints, bushings, interior carpets, door seals, a complete upholstery kit, new seat belt retractor reels (my puppy chewed on the originals), brake pads and rotors, etc. Then there's the 19 batteries. Eighteen 8 volters will have to be replaced soon for about $1800. Might be a time to convert to lithium batteries to reduce weight and therefore increase performance? Your call when you buy it.
|Additional Features||Range doesn't seem to be a problem because the A/C motor and computerized DMOC controller are not very hungry for amps. The 200 amp gauge is seldom at the end of its range (except during full acceleration, on the faster highways or on hilly roads), if I practice a light foot. Regenerative braking is the other real advantage of this A/C system. It not only puts a little back in the traction pack, but it also saves some brake wear. Its great to see the ammeter swing to charge.|
The factory rubber bushings in the front suspension started squeaking a lot. You can hear them in the video. Lubrication didn't seem to help for long. The hard plastic bushings suggested by Electro Automotive made loud clunking noises. I ordered a set of poly-bronze bushings from Elephant Racing that made the noise go away. The new bushings have grease fittings, just like in the old days. Now I'm prepared; I'll give them another squirt of moly grease at the first peep. The Elephant Racing bushings weren't cheap, but they solved my front suspenion noise problem!
Most of my trips are around 12 miles with occasional jaunts over 60 miles. If you need to drive over a hundred miles, either you live in the wrong town, work in the wrong town, or haven't tumbled to the idea of the conservation of energy. I suspect range has decreased after two years, but it does fine for my needs.
I got some new seat belt reels on eBay that latch into the factory inboard ends. Old belts are not a good deal.
This Porsche has a nice Sony radio/CD player with 4 speakers, but I rarely play it because dog and I enjoy DRIVING with the windows open. Driving an EV makes driving a fun skill again!
|Electro Automotive provides a very well designed package. The layout of the battery boxes puts the maximum allowable into the space available in the 914. The design of the battery boxes is both safe and secure. A nice addition might be a drain pipe; so if there is an acid spill, one could flush the boxes without removing the batteries. The wiring instructions are good, but not a substitute for knowing what you are doing. The adapter for the motor is a pretty piece of work. Only downside is that it would might take a year to get a complete kit. It makes a wonderful alternative to the ICE. |
I understand mechanics, electricity and automotive design. I'm glad that I chose the Electro Automotive kit. It's a little more expensive than trying to design it all yourself, but you get what you pay for. High demand at Electro Automotive has made their deliveries slow. I could take you a year or more to get a complete kit. I never received some of the small parts, but that isn't a problem. The design basics are great. Guess everybody wants one. I know why.
It's not just about saving money or oil; it's about saving our planet and setting the example for others to follow.
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