Porsche 914 EV Conversion

OCTOBER 10, 2007

I've got hairdryers and a fuel gauge to work on in the meantime, possibly even an MP3 player. Rennsport deals with racing Porsches, so I suspect I insulted their intelligence when I said the electric motor only puts out 72 ft/lbs of torque and rattled at a "low" RPM of 5400. They said they'd get to it at the start of November.

Porsche 100

Porsche Motor Motors Motoring 100

Porsche 914 EV Conversion

OCTOBER 12, 2007

I also started researching how to drive the fuel gauge with the voltage on the batteries. The fuel gauge reads the resistance of the fuel sensor which varies from zero ohms (full) to 75 ohms (empty). I'll patch this up with touch-up paint, but I'm still frustrated with my clumsiness. Cheers and good night.

Fuel 100

Fuel Kits Plug-in Clean 100

Porsche 914 EV Conversion

SEPTEMBER 9, 2007

The first is a simple op-amp circuit that drives the analog fuel gauge to show the pack voltage (maybe swings from 120V to 155V for a nominal 144V pack?). I've learned a tremendous amount about switching power supplies, shunts, protection circuits and over-current sensors.

DC 100

DC Convert Light Supplies 100

Porsche 914 EV Conversion

MARCH 11, 2007

I suspect I got stuck in the closed garage with all the fumes from the fuel system sitting out on the floor. My buddy Pete is providing some 2x4s later today to hold up the car so I can drop the engine this week. Yesterday was a bummer because I got really sick. Having transmission fluid dumped on my shoulder also stunk wretchedly.

Oil 100

Oil Engine Parts Design 100

Porsche 914 EV Conversion

MAY 5, 2007

In the process of cleaning out the fuel compartment, I removed the washer solution tank. This is picture inside the fuel compartment on the drivers' side. After vacuuming out the fuel tank compartment and cleaning everything else up, I had some more time. The 914 uses pressure from the spare tire (??!!)

Golf Cart 100

Golf Cart DC Kits Lead Acid 100

Porsche 914 EV Conversion

OCTOBER 8, 2007

Perhaps I'll work on the fuel gauge in the meantime. My plan is to drive the car for a week, show it off at the EV meeting on Thursday and take it in to Alan on Friday (if he has time) to upgrade the brake cylinder and align the front end. We can chat about the best direction for the transmission from there.

2000 100

2000 Water Parts Motor 100

Porsche 914 EV Conversion

OCTOBER 6, 2007

Since the RPM gauge and indicator lights are working, I'm thinking about driving the fuel gauge with an opto-isolated circuit from the 144V pack. The next step is to drive around a bit more and see what happens. Perhaps the transmission will fail, but who knows. I'll post that circuit if and when I get it working.

Connect 100

Connect Connected Light Fuel 100

Porsche 914 EV Conversion

JULY 5, 2007

Here are the same cables coming out into the fuel compartment through the large grommet behind the fuse box from the passenger compartment. Here is the left side of the passenger compartment under the fuse box with the cables routed down into the heater duct. I've already added the 3-hole cap-plug provided in the kit.

Kits 100

Kits Plug-in Plug DC 100

Porsche 914 EV Conversion

APRIL 21, 2007

Maybe I can get the "low-fuel" light to come on when the pack is near depletion. An interesting note is that the blue wire shown in the picture above actually drives the tachometer when given a bunch of 12V pulses. It would be great to make a pulse generator that gets this working to match the RPM of the electric motor!

Light 100

Light Kits Motor Motors 100

Porsche 914 EV Conversion

SEPTEMBER 13, 2007

With the charger plugin at both work and home, the PakTrakr fuel gauge doesn't seem to drop below the 80% mark, so I think the batteries will last a little while. The same thing helps when starting from stopped on a hill. The DC-DC converter is still working fine, so the car is actually quite convenient to drive.

Portland 100

Portland Plugin DC Gasoline-Electric 100

Porsche 914 EV Conversion

JULY 30, 2007

It's in the place of the most-positive battery terminal in the fuel compartment. Also, placing it in the fuel compartment makes it much closer to the dashboard, so there will be less signal loss over the shorter wires to the dash. They had a 150 amp shunt-based ammeter there for $90 (ouch). This is the 150 amp ammeter shunt.

Exhaust 100

Exhaust Kits Power Powered 100

Porsche 914 EV Conversion

MAY 4, 2007

Just tell me how much battery fuel I have left and when I need to replace a battery.") I also spent a few hours researching the CAN (controller-area-network) bus that's used for communications in some automotive applications these days.

Batteries 100

Batteries Battery Lead Acid Convert 100

Porsche 914 EV Conversion

JULY 18, 2007

Okay, we now have all the wires from the fuel compartment with connectors on them attached to the battery or components on the relay mounting board. If this has clearance issues, I might have to re-drill some of the previous holes to move the rack. This will be a royal pain after adding all the wires.

Kits 100

Kits DC Batteries Battery 100

Porsche 914 EV Conversion

JUNE 30, 2007

This is inside the driver-side fuel compartment looking forward. Fortunately, the plate is just aluminum and a few minutes with a drill to move the holes closer together allowed me to slide the plate on easily. The two one-inch holes will get grommets for the high-current battery cables connecting the front batteries with the middle pack.

Golf Cart 100

Golf Cart Batteries Battery Connect 100

Porsche 914 EV Conversion

JULY 2, 2007

This is the most-positive power post terminal inside the fuel compartment on the driver's side ready for cable attachment from the front batteries. I unplugged the connector, fitted it through the 2" hole and added the flexguard. Here's the wiring harness connector back through the 2" hole and plugged into the motor controller.

Kits 100

Kits Purchase Mariner Motor 100

Porsche 914 EV Conversion

JULY 23, 2007

The fuel compartment box. Tonight was an evening of heavy lifting. These high-capacity 8-volt golf-cart batteries are 70 pounds apiece. I'll definitely take some ibuprofen before tomorrow. Here are the batteries in the front box. And the rear box.

Connect 100

Connect Connected Golf Cart Kits 100

Porsche 914 EV Conversion

FEBRUARY 9, 2008

If you want a fuel efficient or no-gasoline vehicle, it'll probably be cheaper to buy one already made. This hobby will cost you far more than any amount of money you will save in gasoline when driving it around. The cost of the kit is roughly equivalent to eight years of gasoline.

Convert 100

Convert Kits Conversion DC 100

Porsche 914 EV Conversion

JULY 15, 2007

Here is the 9-in-1 wire for the AC kit pulled through the grommet between the passenger compartment and the fuel compartment. This is looking straight down into the fuel compartment on the drivers side. I finally got to work on the electric car again today. The next major task is wiring up the front compartment.

DC 100

DC Kits Connect Connected 100

Porsche 914 EV Conversion

MARCH 16, 2007

I ran out to Camp914 today to drop off the old suspension and fuel tank with Craig so he can sell the parts and possibly donate to the electric car project. On another front, I'm rapidly running out of space in my house and single-car garage for storing pieces that I've removed from the car. Helens tomorrow and have to finish packing.

Parts 100

Parts Kits Installation IDEA 100

Porsche 914 EV Conversion

JUNE 26, 2007

Inside the front battery box is the middle battery box (goes in the fuel compartment) and a bunch of other parts. Opening up the box reveals many packing peanuts and hidden packages in the bottom. With the first box out, here the front battery rack and box.

Kits 100

Kits DC Store Personal 100