1983 Porsche 911 SC Targa

Tuesday, November 26, 2013

Registration and Taxes

I purchased the 911, in gas form, nearly two years ago.  The registration expires next month. Most gas vehicles where I live have to pass a vehicle emissions test as a condition for registration renewal.  By registering the car as an electric powered vehicle, I will be exempt from the emissions testing.  I’ve heard countless tales of bureaucratic confusion surrounding the process of registering a vehicle that has been converted to run on electricity.  I was expecting and prepared for an ordeal.  Fifteen minutes after stepping into the department of motor vehicles office, my car was registered with the state of Oregon as an electric powered vehicle.  The whole event took a little extra time because the clerk was so skeptical that the process could actually be so painless that she called her supervisor over to confirm that there was no inspection, documentation, extra fees, sworn and notarized affidavit, or clearance from a mental health professional required to complete the transaction.  There was just a simple change made to the database under fuel type: electric.

The supervisor commented that he was aware that a number of people have installed fork lift motors on small pick-up trucks, like the Chevy S-10 and the Ford Ranger, but never on a vehicle that was nice, like a Porsche.  The public perception of converted electric vehicles is still dominated by anemic lead acid powered examples.  Without knowing that lithium technology is now viable, the concept of an electric sports car conversion would be incongruent.  My goal that day was to walk out of the office with registration stickers, and everything was going smoothly, so I didn’t feel it was the proper time and place to explain that electric cars have changed and that my conversion could outperform the stock gas configuration.  The phrase, “Anything you say can be used against you…” was on my mind.
After confirming that I was now exempted from pollution testing, the clerk commented that I would also not be paying gas taxes, a tacit admonition that driving on public roads without paying the gas tax is dishonorable.  

 Oregon was the first state in the United States to enact a fuel tax, back in 1919, with the revenue to be used for building and maintaining the road system.  I believe a road is a public good, and I support funding well administered public goods.  I also support a tax based on fuel consumption, because it creates an incentive to consume less fuel and produce less pollution.  As the average fuel efficiency of road going vehicles has increased over the years, and people are buying less fuel, the fuel tax revenue has been declining. 

And so I wondered, just how much tax was I avoiding by driving an electric car.  In 2009, the state of Oregon collected $1,394,000,000 USD for maintaining and building roads and 13% of that total was derived from the fuel tax.  I’m still participating in the other 87% of the revenue generating categories, so I’m OK with not paying the gas tax and still using the public roads. 

Here is how the rest of the road funds in Oregon are sourced: 37% from the federal government, 25% from bonds, and 13% from vehicle and motor carrier (commercial) fees.  The remaining funds come from local sources, and an official sounding category – miscellaneous.

(Source: U.S. Department of Transportation- Federal Highway Administration: “Revenues Used by States on Highways”: 2009; http://www.fhwa.dot.gov/policyinformation/statistics/2009/sf3.cfm) 

Wednesday, August 28, 2013

Wheel Alignment and Weight Distribution

I can’t say enough good things about Rothsport Racing, an automotive shop in Tualatin, Oregon specializing in Porsche.  I took the car in to get an alignment after switching to stiffer torsion bars.  The shop was great. There were six car up on lifts, a machine shop, and several 911s, some set up for full racing. I was a little apprehensive bringing an electric Porsche to a Porsche racing shop, because I wasn’t sure how the car would be received. Jeff Gamroth, the proprietor, introduced himself, and after a quick show and tell, we took the car for a quick spin down the street. He liked the torque, but said the lack of engine noise was strange. We then pulled the car around into the shop bay, and five mechanics immediately flocked to the car. The silent entrance certainly got everyone’s attention. “Was that you guys? We heard a strange sound going down the street.” Everyone seemed OK with the electric modifications, or at least kept their horror in check. There were lots of questions about the batteries, range, safety advice to avoid electrocution while working on the car, and for the first time someone noticed my tachometer sensor mounted on the electric motor tail shaft. One of the guys joked, “At least you didn’t bolt on an LS2,” a jab at the practice of installing a Chevy Corvette V8 motor in a 911.

The alignment did wonders for the handling of the car. The steering is lighter and more precise. As a bonus, they also put the car on a scale. My conversion tips the scale at 3158 pounds (1432 kg), and is 408 pounds (185 kg) over stock. The front is heavier by 231 lbs and the back 177 lbs, shifting the front/back weight distribution from 38/62 to 40/60.

Friday, July 26, 2013

1000 Miles, 1000 Amps

I recently logged my first 1,000 EV miles. It was time to bump the Soliton 1 controller to the maximum setting of (cue the sinister movie sound clip) – 1,000 amps. There are a couple reasons to begin with a low current and ramp up to greater performance over time. While testing out the new EV system, a low current setting will minimize damage, if there is a problem. Another reason is I’m using a motor with brushes.

When a DC motor is new, the brushes do not make full contact with the commutator. Small imperfections in the contour radius at the brush and commutator interface increase the electrical impendence of the motor. If you try to pass a lot of current through new brushes, the motor is at risk of arcing and overheating. On the bench, I ran the motor for 30 hours at 12 volts. Then, when first installed into the car, the gradual increase in motor current allowed the brushes to properly seat as the high points on the brush get worn away.

With the 1000 amp limit, the difference in performance is significant and amazing. The extra 40 kilowatts of power (50 HP), relative to 600 amps, makes the car fly. The stock 3.0 liter internal combustion engine (ICE) output was rated 127 kW (170 HP). As an electric conversion, I recently logged a run on my commute to work with a current draw of 890 amps producing 120 kW of power (160 HP). 

The logged run did 0 to 60 MPH in 9 seconds. I started in 2nd gear and at 5.7 seconds I shifted to 3rd. The 0 to 40 time was 4 seconds. If I open up my motor RPM limit to 5,500 I can reach 60 MPH in second gear and avoid the 2 second penalty of shifting. 2 seconds is a long shift, but I’m still getting used to this gearbox and after 97,000 ICE miles, the synchro-mesh is not in best form . The car seems to be on par with the stock performance, especially given that with the electric motor, peak torque is available between 0 and 5,000 rpm. I need to find an open bit of road with no traffic and see what happens when I push the full 1,000 amps.

Monday, July 22, 2013

Celebrate Hillsboro and Another Video

I had the car on display at a local event called Celebrate Hillsboro – a city festival with music, kids activities, sports, bicycle rides, and a farmers’ market. My car was positioned in the intersection right in the middle of the event. The car generated a lot of positive attention.

A few people expressed disappointment in my choice of donor. Some were misinformed on the performance capability of electric drive and others were dismayed that I messed with a classic. But the response was overwhelmingly positive. I even met a few people that are currently converting their own vehicles. By far the most common questions I get are range, cost and battery life (100 miles, a lot, and 3000 cycles).

I’ve received a lot of requests for another video. I’m pleased that the controller in quiet mode no longer generates that obnoxious 8 kHz switching buzz.