Archive for May, 2008

Free gas

Monday, May 26th, 2008

I’m estimating a full charge costs $2.50 for 45 miles of driving, which works out to about $1.80/gallon. But it gets better.

In planning for my second trip to Northridge, I found a website called evchargenews.com. A tremendous resource, it has a database of all the EV charging stations set up under the California Air Resources Board’s Zero Emission mandate. It’s conveniently designed using Google Maps so that not only can you get reports from others about the station, but also print an aerial photo. Though they have been idle for ten years for want of EVs to plug into them, it turns out most of the 30 or so stations in the San Fernando Valley still work. I checked to see if there was one near CSUN where I could charge while I’m riding with my bike club on Saturdays, and sure enough there’s one on campus with 110V AC.

So early Saturday morning I drove down with bike in back , plugged in, and took my bike on a 5-hour ride.

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When I got back I had a full charge courtesy of the city of L.A.

Idiosyncrasies of lead-acid

Sunday, May 18th, 2008

You may have noticed how if you leave a flashlight on until the bulb is dim, then turn it off and set it aside for an hour, then turn it on again, it regains some of its brightness.

This property seems to be typical of all lead-acid chemistries. I drove the car to Northridge (16 mi) this morning and back, and after 32 miles of highway driving it was done – pedal to the metal just to keep up with traffic. I had breakfast and went back to the car an hour later, and it had “grown amps”, from 102V to 118V. I knew the voltage would not last long, however, so I took it out around town and got another 8 miles out of it before it was back down to 98V. Kaput.

So 40 miles is pretty much the usable range, and 65 mph the top speed. Both are a bit less than I expected but acceptable. The part that does take some getting used to is this: with internal combustion you can expect the same performance on a full tank or 1/8 tank, but not so with batteries. Performance gradually decreases from the first time you step on the pedal until the batteries are drained. It is not a linear decrease (barely noticeable for the first 20 miles) but something to be aware of.

No more lowrider

Monday, May 12th, 2008

As I’ve mentioned before, it’s difficult to find performance parts for a discontinued 10-year-old subcompact. So I’ve been making do with what I can cobble together.

Below are original struts/springs on left, new on right:

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Compressing the springs to fit them into the struts is the challenging part. They need to be squeezed with 400-500 pounds of pressure using a special tool, so it’s one aspect of car maintenance that many amateur mechanics leave to pros – it can actually be dangerous. But because the pros I talked to were either inept or disinterested it became my job. Below is the front left strut in the vice with the springs compressed. Not all that dangerous if one maintains a “healthy respect for the restrained energy” (one blogger’s words).

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The front left strut installed (note pitting in brake disk due to rust from being outside):

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After installing the front springs the car rode a full two inches higher than I had calculated for. I checked the stiffness by standing on a spring while Nick measured with a ruler how much it compressed, and the 150 lbs/in rating was accurate. So I’m not sure where the calculation fell through, but serendipitously with all four springs on they “settled in”, and the car appears to be riding just about an inch higher than stock. It’s good enough and makes for good speed bump clearance. Took it out on the freeway yesterday and got it up to 65 mph with room to spare. The KYB gas struts/shocks have a nice feel and do a good job of damping the stiffer springs, although in a perfect world would be slightly stiffer to match. The speed and pickup of the car continue to impress; the range is a mild disappointment — I can’t really count on more than 30-35 miles. I’m hoping that as the batteries are broken in the range will improve.

Suspension

Wednesday, May 7th, 2008

Two springs and four struts arrived today. The springs are rated at 150 lb/in which is roughly 50% stiffer than the stock springs for the car, and hopefully will be enough to raise it back close to the original ride or at least keep it from bottoming out.

I would be lost without a find I made, a website where another Aspire enthusiast describes a suspension overhaul on his car using parts which were designed for the ‘93 Ford Festiva. Using his instructions I installed the left front/strut (KYB GR-2) and spring (Gravity) and though the dimensions are not exact it seems like a good fit. Hopefully I can get the left rear shock and spring installed tomorrow, then lower it back onto the wheels and see how it sits.

On the road!

Monday, May 5th, 2008

Ok so I’m a crappy blogger.

It takes a special mindset to blog. You have to be extremely committed to routine, and that type of commitment is diametrically opposed to the variety required to finish a project as off the cuff as this one. So I haven’t posted for almost four months, but the good news is that thanks to good weather in my outdoor workshop we’ve spent the time most productively, and not only is the car close to being “done”, but it’s already racked up 100 road miles and actually drives pretty well.

Since my last post in January:

Installed fan in rear battery box (120VAC). It comes on when charger is plugged in. Below, circle is marked to cut hole for fan.

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Wiring. Went through wiring the Aspire electrical manual and chased down every circuit under the hood that might need to be connected to something and did it. Then chased down the wires that were useless (oxygen sensor?), cut them off, and threw them away. Also installed vacuum switch and vacuum pump for power brakes. When the vacuum gets too low, the switch turns on the pump and it reduces the pressure by 20 psi before it shuts off. Below the pump is just above the controller and the switch is mounted to the shock tower above that. Vacuum tubing is not yet in place.

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The battery box was installed in the rear of the car, and the polyethylene sides, which had bowed during the welding process, were glued to the frame.

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In late March and early April I entered full burn mode and only occasionally took photos. The goal was to be done for Nick’s school’s Earth Day celebration on 4/22, at which I was invited by his science teacher to display the car. Sucker that I am, I let the battery salesman talk me into the next size up (”EVERYONE uses the T-875s”) which will provide more power but also add 50 lbs of weight…cutting it pretty close to the GVWR, or Gross Vehicle Weight Rating. Also during this time the wiring was completed, the 2/0 power cable was cut and crimped, and the charger and instrumentation were installed.

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I was amazed at how smoothly everything fell into place during this time. Then the rest of the car had to be put back together: putting the wheels on, the seats in, the hood on. We took it out for its first trial run on Sunday 4/20.

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Rear battery box, with batteries installed and wired

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With 882 extra pounds it’s sitting low, so we take pains to avoid streets with speed bumps, but it has good pickup and is actually fun to drive. On 4/21 I got it up to 45 mph with plenty to spare. For Earth Day Nick put together a display board with FAQs about electric cars, and I made up some cards to identify parts under the hood.

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The next step is to get new struts and springs to lift the car back up close to its original clearance. I have KYB struts and Eibach springs on order. We’ve done the math with regard to clearance, stiffness, etc but because the weight is only a rough estimate we won’t know if these parts are right until they are installed. Because the Aspire is about the last car you’d want to “soup up” there are very few aftermarket choices for suspension, so I’ve had to order parts which are not the exact dimensions I need. Fingers are crossed.