I am proud to be the owner of, a red 1974 914 ex-2.0 liter now converted to high-performance electric drive. Built originally in Santa Cruz, CA as a sport commuter, this E-Fourteener performed so well on its mountain road route that it has been extensively raced and rallied. The car entered its first race in 1992, when Arizona Public Service Company (an electric utility) and the new Solar and Electric Racing Association first began EV racing by founding the APS Phoenix Electric races.
Excited by # 13's performance in the 1993 APS Phoenix Electric Stock I modified it and entered it in the 1994 Phoenix race as part of an all-women's' electric racing team (WE'RE-IT). The car has run every year since and is now nearly legendary in that race, usually placing in the top four each year. In 1996, it took 4th in the stock electric endurance race and 2nd in the stock sprint. It also had the fastest qualifying time in the stock class and the fastest lap.
So What IS an Electric 914 Anyway?
An E-Fourteener is a gas 914 that has been modified to run on electricity=2E It has been made into an electric vehicle or "EV". Instead of a fuel tank, the car runs on batteries and an electric motor replaces the gasoline engine. Instead of fuel injection/carburetion and a mechanical throttle linkage, the car has a solid-state electronic controller. The gas pedal becomes the "go pedal", operating a variable resistive device that is hooked to the controller.
How Does It Work? Power is stored in batteries inside the car. During driving, the car's electronic controller senses the signal from the variable resistor, (or "potbox") at the go-pedal. In response, the control module regulates current output from the batteries. The controller increases or decreases current output smoothly to eliminate jerkiness and provide the same driving characteristics as a gasoline car. The rest of the vehicle (brakes, 12V electrical system, shifting) is the same as the gas car.
In most (but not all!) electric conversions, the car keeps the clutch and transaxle, so that shifting operates normally. The electric motor is coupled to the transaxle by means of an adapter plate. These plates are commercially available for any vehicle, although they were first made for VW-based cars. The plate has several functions. 1. It mounts the electric motor on the transaxle end-bell. 2. It includes a coupling that mates the transaxle output shaft to the electric motor shaft 3. It includes bearings that ensure that the two shafts are aligned on-center. 4. Along with the transmission end-bell, it helps house the clutch and flywheel.
#13 (known by its APS Electrics Race car number since 1992)
1973 2.0 L 914 2.0 L, red w. black top, converted with Electro Automotive basic kit in 1991-92. Modified to run in Arizona Public Service Electrics Races, stock class, participant each year from 1992-1996. Present configuration Motor - Advanced DC 9-inch series-wound DC motor, rebuilt and Kevlar-strapped Adapter - mates motor to 5-speed transmission, houses clutch. Race Controller - Auburn Scientific Grizzly, 600 Amps at 192 V Street Controller - Curtis 1231C, 144 V, 500 A Battery type - Electrosource Horizon 12N95 sealed lead-acid 12 V batteries Top speed - 95 mph, maybe higher. 0-60 in 9-11 sec. Full rollcage Additional instruments - DC watthour meter, ammeter, voltmeter, Badicheq battery monitoring system capable of interface to IBM PC Charger - Mentzer "Cube" charger, 168V, 16 A. Rear suspension - Custom full adjustable nickel-plated coilover shocks by Leda of Great Britain Front suspension - Leda custom full adjustable nickel-plated front race struts combined with 23mm torsion bar. Custom fabricated anti-roll bar
A Personal Path I came to 914s via a rather different way than most people; I became interested in them as electrics. None of the 914s I have owned have been gas, except for a brief period before conversion.
As an electric vehicle activist and advocate, I have designed, built, driven and raced electric 914s. I built my first EV, a converted 1969 Baja Bug in 1992 after (and as a result of) the Persian Gulf War. From the Bug, it was an easy step to other VW-based cars. The 914 attracted me due to its handling, chassis strength, good aerodynamics(Cd of .38 and low frontal area) and battery-handling capacity.
Electric - the 914 for the '90s by Clare L. Bell
[Photo #1 - Caption: Electric 914 gives rides at the Automotive Press Association's Ride and Drive 1994, Sears Point Raceway, CA. Driver, Clare Bell]
Ever since it appeared in 1969-70, the Porsche 914 has been known not only for its excellent handling but also its adaptability. The standard flathead four 411 VW engine has been replaced in many 914s by various powerplants. Chevy V-8s, Mazda RX-7 rotaries and even the Porsche 908 racing engine have all been successfully transplanted into 914s for increases in power and performance.
Now comes the newest conversion of all -- electric. To the traditional demands of car performance are added new requirements for fuel economy, lower emissions, and independence from fossil fuels. Electric also brings the 914 into an area of rapidly-developing automotive technology that promises to yield even higher performance for those who seek new and different ways to "hotrod" the beloved Fourteener.
[Photo 2 - Caption: Classy ride. Don Gillis' 914 EV commuter is detailed to perfection. This is a lightweight conversion, running on 12 volt batteries. (1996 Electric Auto Association Rally, Sunnyvale, CA) Photo: Lee Hemstreet]
[Photo #4. Caption: Black 1973 914 EV converted and raced by Cal State University at Long Beach. Shown at the 1996 Phoenix APS Electrics, held at Firebird Raceway, Phoenix, AZ. Photo: Paul Compton ]
Some History I am certainly not the first to use an electric powerplant in a 914. When engineers and hobbyists began converting cars in the 1960's and 70's, using parts adapted from other industries (aircraft starter-generators as traction motors, for instance), their attention inevitably fell on the Porsche 914. The first modern one may have been done in Hawaii, in the late '70s. There is also some evidence of an electric 914 running around Campbell, CA in 1984.
[Photo #5. Caption: Number Thirteen runs for the Women's Electric Racing Team at 1995 Phoenix APS Electric Stock. Mary Ann Chapman, driver.]
Inspiration Since #13 was built, she has inspired other 914 Evs. There are at least 15 either on the road or being built. In her original configuration, "the Thirteener" served as a model for the VoltsPorsche conversion kit developed by a small Northern California company called Electro Automotive. This kit includes all the parts and instructions needed to convert a stock 914 from gas to electric.(Electro Automotive is located in Felton, CA, tel: (408)-429-1989). They have flyers on the VoltsPorsche kit.
[Photo - First VoltsPorsche, "Black Magic". This car was built in order to develop a commercial conversion kit for the 914. She also served as an "EV ambassador to the general public" by giving rides and appearing in shows. (EAA San Francisco Bay Area Electric Auto Rally, 1995)
I worked together with Electro Automotive to build the first VoltsPorsche=2E I provided the donor car, a space-black 1976 2.0L. I also paid for the kit design/fabrication and helped assemble the final car. The donor car was a space-black 1976 2.0L. The result was VoltsPorsche One, "Black Magic", which went on the road in early 1995. This car demonstrated that #13's performance was no fluke by duplicating the range and acceleration of the earlier car.
"Black Magic" has proved to be a reliable high-mileage EV. In the Santa Cruz mountains, the car has shown a working range of 40 miles, and recently completed a 46-mile test run. This included a 2300 ft climb from Santa Cruz up Empire Grade to Bonny Doon at speeds between 35-40 mph (this is the speed limit on these roads).
"Black Magic" now lives in San Bruno, CA, where she has to tackle the steep hills characteristic of the San Francisco area.
Photo #7. Caption: [Clare and #13 explain EVs to some interested young women]
Do batteries make the car heavier? In some cases, yes. It depends on the kind of batteries used and how many=2E The trend is toward lighter Evs. Curb weights for finished cars can vary from 2500 lb to 3200 lb. (see car specifications below for details)
[Photo #8. Jaws? No, Just Black Magic, showing how clean an electric conversion can be. Polypropylene battery boxes with hold-downs fit nicely into the 914's front trunk. Photo: Lee Hemstreet.]
Can the 914 handle extra battery weight?
Yes. The original 914 chassis is extremely strong. It was designed in a multi-cell structure to absorb and diffuse collision impacts. It also has two heavy box-beam channels running along the sides of the car, so that even with the roof off, a 914 has more chassis rigidity than a 911. People have walked away from 60 and 70 mph head-on collisions in 914s. In addition The car was designed to handle much more weight and power than Porsche ever gave it. Racers routinely drop big-block V-8s in Fourteeners and Porsche actually built two with a 908 racing engine. These cars are driven harder than any car on the road, since they handle so well, and they survive it. There are also chassis-strengthening kits, since some people do drive gas 914's so hard that the body can separate from the firewall at the rear shock-towers ("Flexy-Flyer syndrome).
[Photo#9. Caption: New advanced sealed 12V batteries, such as the Electrosource Horizon, can fit quite neatly into the 914's "letterbox". Battery jugglers:, left, Ruth MacDougal, right Clare Bell.]
[Photo #10. Caption: A closer look. The straps were added to facilitate loading.
Since 914s are used a lot in competition, there are all sorts of after-market brake and suspension mods available. Some 914 racers upgrade their brakes to 911 calipers and rotors, which are 11 inch drilled disks and give better stopping power. That requires going to 5-lug 911 wheel hubs. The car is definitely heavier and does take a little more time to stop. I allow for that in my driving. Eventually it becomes habit, part of the "feel" of driving the EV.
Technical specifications on the cars:
VoltsPorsche One - "Black Magic" space-black" 1975 914 2.0 L, first car converted in 1995 with Electro Automotive commercial "VoltsPorsche" kit. Motor: Advanced DC 9-inch series-wound DC motor Adapter - mates motor to 5 speed transmission and houses clutch Voltage - 120V DC Electronic controller - Curtis 1231C, rated for 144V and 500 Amps Battery type - US Battery 2300 Charger - K and W BC-20 with booster transformer Rear suspension - 180 LB Bilstein coilover shocks Front suspension - largest available torsion bar. Additional instruments - Battery pack voltmeter, ammeter, auxiliary battery voltmeter Top speed - 85 mph. Range - 70-80 miles on one charge.
Former configuration - same as "Black Magic", which was based on #13 before that car was modified for racing.
A Virtual Drive
Photo #11. Caption: [At the wheel of Challon-bodied 914 electric built by Bob Hadden of Voltage, Inc. EVS-12, 1994, Anaheim, CA]
Let's take our E-Fourteener out for a spin. The car starts with an ignition key, just like the original. However, when you turn the key, instead of hearing a starter whine and the engine fire up and start rumbling, you only hear a soft click and a green light comes on in the dash. Handbrake off. Is the car alive? Yes, it is. It is waiting silently for the pressure of a driver's foot to release a surge of power, instead of wasting energy in noisy idling.
Is the shift lever in neutral? In the stock 914, it had better be, or the clutch should be depressed so that you don't stall the engine. In the electric, it doesn't matter! In most EVs, the electric motor runs only on demand, doesn't idle and doesn't have to rev up to deliver its full power. Most EV motors actually have their strongest torque, or turning power at nearly zero RPM! This leads to some characteristics that make the car much easier to drive, especially for those who are just learning or who are unfamiliar with a stick shift.
Photo #12. Caption: Roof off, ready to go!]
One very nice feature is that you can't stall the electric motor. If the car is in neutral, or the clutch is in, the motor will just spin, (making a sexy sound like a jet engine heard at a distance). If the car is in gear and the clutch is out, it will just start forward.
This behavior means that you can drive the E-Fourteener in two different modes:. 1. Automatic or semi-automatic, suitable for new or inexperienced (non-manual shift) drivers. Leave the car in first or second gear, press down the pedal and go. The start may be slightly jerky, but it gets off the line. Absurdly easy.
2. Manual shift mode, for those who prefer to work the stick. By revving the E-motor and slipping the clutch, experienced drivers can pull all the same shifting stunts as they do with the original. And again, the motor can't stall. Still very easy.
OK, enough about shifting. Back to our drive. We'll start in second gear, clutch out.
Ease down on the pedal. The first thing you will hear is a slight "click-chunk", then a slight keening that fades away as the car begins to move. That "click-chunk" is the main contactor closing( a contactor is just a big high-current switch that operates off a low-voltage coil instead of a push-button). A signal from the pedal first closes the contactor so that current can flow out of the batteries, through the cables to the controller.
Press harder on the pedal. The controller reads that as a change in resistance and feeds more current and voltage to the motor. The car surges forward in a stealthy silence; the only sound is the crunch of gravel under the tires. The only indication of power being drawn are needles swinging on the dash instruments (current meter and voltmeter.) The amp-meter pegs at 200 briefly, then the needle-tip slides back down the scale to about 100 as the car glides along.
How much power are we pulling? Ok, the voltmeter is reading say, 120 and the amp-meter is at 100, which makes it easy. In electricity, power =3D volts x amps, so we're drawing 12000 volt-amps or watts. A kilowatt is 1000 watts, so the car is pulling 12.0 KW. That much? Well, it takes a lot of energy to move a car, even a little 914!
Motors used in Evs tend to run out of torque (turning power) at higher RPM (though they are most efficient at high RPM!. Like gas engines, they have an optimum power band, which is about 0-8,000 RPM. For more get-up-and go, it's time to shift up. Shift UP?
The fact that electric motors have their highest torque at low RPMs leads to a rather paradoxical fact for those who are used to driving gas cars. Instead of shifting down for more power, you shift up. (Lowering the motor speed, thus increasing the torque).
OK, stick her in third and stand on it. The amp-meter jumps to 300, then backs down as the motor revs up. A definite kick-in the pants feeling. The voltmeter does the opposite, though with a much smaller excursion. (We'll discuss that later). Now she's cruising.
Note that the handling and steering are pretty much the same as stock. The car still has its agility and cornering power. The sound of the wind and the tires on the road is like the breaking of ocean waves. If the car is a typical Fourteener, it will "talk" to you in little bumps, squeaks and twitters (especially if you haven't Armor-alled the vinyl on the targa bar where the roof sits).
Take it to fourth and she's really sailing. Hey, this is a ton of 914 fun, but with a different flavor.The motor is singing rather than roaring in your ears. Around the corner like she's on rails (a little strategically-placed battery weight helps).
Traffic ahead. Remember your trail-braking technique. The car slows quickly, without fuss, and without need to punch in the clutch (remember, you can't stall an electric). Then use the clutch for a quick downshift and she's off again.
All good things have to have an end. The E-Fourteener pulls back into the driveway at home base and rolls up beside a standard outdoor 110V electrical outlet (it may also use 220). A heavy-duty electrical cord plugs into a reciever on the car, then into the outlet. The charger starts to hum, ....no visits to the gas station either.
Fewer Headaches Many of the traditional 914 headaches go away with conversion to electric=2E The E-Fourteener doesn't need the fuel-injection control computer and relay system that often fails and keeps the original car from starting. It doesn't have the leaking fuel lines that have started engine fires in some 914s. The mispositioned starter battery, which drips on fuel lines and weakens the rubber, making them leak, goes away completely.
It doesn't need sparkplugs, tune-ups, valve adjustments, gaskets, mufflers, emission-control systems, engine rebuilds, exhaust repairs, valve adjustments, fuel pumps, fan belts, engine oil, etc.
And...IT DOESN'T HAVE TO BE SMOGGED!
Emission control requirements, although needful and necessary, are killing 914s. California cars, especially, have to meet such stringent requirements that many simply can't pass. 914s that have replaced the fuel-injection system with high-performance carburetors are no longer street-legal in many states. Many otherwise roadworthy Fourteeners have been condemned to the junkyard by smog control requirements.
All that is avoided in the E-version. Once the "E" motive power designation shows up and stays on the registration, the car never again needs to be taken to a smog check facility.
914 EV Autocross
Recipe for killer electric autocrosser
1971 914 (lightest 914 built) stripped to 1600 lbs 1227 long 8-inch ADC motor High-voltage high amp controller (Auburn, DAX, Otmar's, etc.) 192 V worth of Optima Yellowtops Good high-amp terminal connections 6- or 7-inch rims with Yokohamas Fiberglass or carbon-fiber hood and deck lid Skinned or fiberglass doors Remove dash (heavy) Short-shift kit Heavy duty racing clutch Drilled aluminum brake rotors 911 aluminum brake calipers Racing seat Bilstein adjustable-platform coilover shocks Largest available front torsion bar Keep car at original 50-50 weight distribution Maintain low polar moment of inertia by loading batteries toward the middle of the car as much as possible.
Mix well, charge up and stand back. Warning - it is hard to spin a 914, but if you do, you go round like a top, about 2 1/2 times.
Be ready to comfort grieving 911 drivers. Be ready to fend off people who want to buy your car on the spot (unless you want to sell it).
914s used to and still do, dominate autocross, especially in the tighter twistier tracks.
I have autocrossed my #13. SCCA has put the car in various classes, but they seemed to have settled on OSP (Open Street Prepared. When I've put an experienced 914 autocross driver in #13, she gets times that are equivalent to the gas-powered stock 914s. Mine isn't the ideal, but she's not bad. In autocross configuration, she has a 9-inch ADC, 144 V, skinned hood, deck and doors, 5 1/2-inch rims with Yokohamas,full rollcage (don't really need for autocross and it's heavy), stock brakes with Ferodo pads, stock tranny and clutch. With batteries out she's 1850 lbs. With batteries in, she's about 2500. With driver and gear, 2640.
Photo #13. Caption: Hanging out (literally) during preparations for Phoenix 1995. Left, Mike Slominski, of Mike's Auto Care in San Mateo, CA. Photo: Ruth MacDougal]
For more information: Electric Auto Association 1-800-537-2882 (I am the editor of their national newsletter, Current Events).
ElectroAutomotive (VoltsPorsche kit) (408)429-1989
EAA Chapter Websites:
Last modified 01/22/99