Thursday, September 29, 2011


On Friday, after a long day of technical sessions, EVCCON attendees turned outside to nice weather and a bit of a play day. We had a weigh station where attendees could get the weight and distribution of their cars, a drag race, and an autocross.

To spice it up, EVTV had offered a purse of $2500 to the fastest full bodied four wheel car at the event.

At the dinner Saturday night, I presented Ron Adamowicz with a check for $2500. His Warp Factor II Camaro, featuring two Netgain Warp 11HV motors and two Zilla 2K controllers turned in a time of 11.50 seconds and a speed of 91.20 mph to win the event - on airport ramp concrete which was a bit "grabby". The Team Haiyin Camaro is sponsored by the Haiyin Battery Company. Ron has an agreement to distribute these very small 6.5 AH high power pouch cells and describes them as perfect for racing. Ron did describe these $29 cells in detail at session on Saturday morning. More info at his Battery Shop web site. Congratulations Ron.

David Hrivnak was awarded a trophy for fastest production car for his 2008 Tesla Roadster posting a time of 13.13 reaching a top speed of 88.25

The race of the day was never actually run as they didn't go head to head. But Sebastien Bourgoius 1978 Porsche 911 featured TWO Netgain Warp 9 motors and an EVnetics Soliton1 controller came in at 14.66 seconds and 89.15 mph while our own 1957 Porsche Speedster Redux with ONE Netgain Warp 9 and the SAME controller posted a 14.75 at 78.5 mph. Next year we will have to run these two cars head to head. In fairness, Sebastien's car left the aromatic smell of burning clutch wafting over the crowd the full length of the raceway, while Matt Hauber chirped merrily down the strip in our own REDUX. No sympathy. Bourgois was IN our shop when we burned a stock clutch out on Redux and replaced it with a Stage IV Kennedy competition clutch. Nonetheless, on building his 911 he avowed a stock clutch would be adequate. Build and learn. The disparity in top speeds between the two cars indicates that once under way, the 911 was indeed fast. But until he gets a clutch, we can probably take him in the 1/8th mile.

11.50 // 91.20
1981 Camaro Drag Car - Ron Adamowicz

13.13 // 88.25
2008 Tesla Roadster - David Hrivnak

14.66 // 89.15
1978 Porsche 911 - Sebastien Bourgeois

14.75 // 78.51
1957 Porsche 356 Speedster - EVTV / Matt Hauber

16.75 // 80.70
Seven Illuminati - Kevin Smith

17.14 // 76.14
Car #128 ???????????

17.21 // 69.79
Porsche 904 Carrera GTS Duane Ball

17.69 // 67.40
1973 Opel GT - Charlie Rickman

18.54 // 73.49
2007 Toyota Prius Limo - Steve Woodruff

18.90 // 66.41
2000 BMW Z3 - Tim Catellier

19.12 // 71.42
1955 Porsche Spyder 550- EVTV / Brian Noto

19.81 // 68.30
1974 Porsche 914 - Rich Rodriguez

19.84 // 65.16
1981 VW Pick-Up - Jim Hanna

20.22 // 63.06
1999 Saturn SL1 - Daniel Lynn

20.29 // 54.50
1993 Ford Ranger - John Yecker

20.35 // 61.97
2000 Ford Ranger - James Edmonson

21.26 // 47.63
1960 Austin Healey - Fred Behning

21.27 // 58.86
1987 Dodge Daytona - Jason Horak

22.57 // 61.92
1957 Beck Porsche 356A - Eric Kriss

22.86 // 57.92
2001 Subaru Forester - Michel / Denis Bondy

24.02 // 54.43
1993 Geo Metro - William Dennis

24.82 // 44.33
Car #185 ???????????

25.18 // 42.53
2005 Porsche Cayenne - Daniel Yohannes

The other head to head we will have to run again is Richard Rodriguez's Porsche 914 at 19.81 seconds and our own 1955 Porsche Spyder 550 at 19.12 seconds. These DID go head to head and it was an exciting heat.

But as long as I live, I believe the definitive image I shall carry to the grave of "drag racing" is Steve Woodruff in a 2007 Toyota Prius STRETCH Limo - obviously the definitive drag racing monster machine. We believe this to be an EVCCON exclusive. You'll rarely see such in an NHRA event.

The objective here was to take a break from two solid days of technical sessions, get out in the sunshine and play with the cars. We drove each other's cars in the drag race where you could line up for run after run without restriction. Looked at the cars between heats. Talked about the builds. And drank Stag beer out of a keg TRAILER with spigots down the side. We had announcers and screens showing times which made it much more interesting as a spectator event. And we really didn't have to deal with the OTHER detritus of being at a real track on race day with a lot of other events. It was perhaps not as official, but a lot more fun and ALL about electric cars. And the car owners now know exactly what their cars/limousines can do in a timed quarter mile.

Rumor has it that NHRA is going to add electric classes to the big time drag racing circuit, making the weeny NEDRA/ECEDRA events rather obsolete on contact. But we think we can continue our own unique "drag race" as a fun day in the sun at each EVCCON. We hope to add a dynamometer to next year's event so you can weigh your car, get a dyno printout, run the quarter, and do the autocross. We'll offer a purse again next year and hopefully lure some other electric cars to compete with the purpose builts like Ron's Warp Factor II to spice up the show. But it's all about fun and electric cars.

There's just nothing like tanking up on a bellyful of Stag beer, playing with some high voltage, and going for an afternoon drive...

Team Illuminati was actually a pretty serious contender in the Progressive Auto Insurance XPrize held last year. They lost their transmission at a crucial point in the competition and dropped out. They again demonstrated this technique at the EVCCON Autocross track. You can hear it let go in the last seconds of this video.

Wednesday, September 28, 2011


Christopher Fisher has created a private forum on LinkedIn for EVCCON attendees to stay in touch. I kind of like this service as everyone has a photograph next to their posts and I'll e able to connect the face and name. No little kid "handles" and stuff on LinkedIn. More of a professional service.



Jack Rickard and George Hamstra at EVCCON 2011.

Electric cars rolling out of 100,000 garages across the land. Lead, follow, or get the hell out of the way....

I LOVED this photo....

Thanks George...

EVTV Build Your Dream Contest Winner Announced at EVCCON 2011

The Electric Vehicle Conversion Convention is mostly over. Actually about 16 showed up at the house for Sunday dinner and we've had three or four linger till midweek - the convention that just won't end.

I'm drained and recovering. We have a TON of video and photos - actually it has me a bit overwhelmed. I don't know how to sort through it all and there's got to be 70 hours of video and so forth here. It would take months.

But we are going to do some announcements on the highlights.

First is the announcement of the winner of our EVTV Build Your Dream Contest. This thing has gone on for over a YEAR proving just how bad we are at holding a contest while making it up as we go along. Reminds me of the my old partner Phil Becker's favorite analogy. "We have the skills = we know how to make parachutes. We have the materials to make a parachute. We have the equipment to make a parachute. Now all we have to do is jump out of the plane, make a parachute, get it on, and pull the cord BEFORE we hit the ground."

I'm very pleased to announce that Brandon Hollinger of ampRevolt has won the EVTV Build Your Dream Contest with his proposal to convert a 1971 Austin FX4, aka a London Taxi.

Ultimately, the winner was selected by Internet ballot with our viewers making the selection. This was a great relief to me personally (I can't take the pressure). But I'm extraordinarily pleased with the result as you'll see.

The contest seesawed between Brandon and Mike Picard's 1952 Willy's Jeep for most of the summer. But AFTER we closed visibility on the horse race for the final two weeks, Hollinger put together a video appeal for votes he posted on YouTube. It's actually quite artful, and apparently made the difference in the contest as we had a sudden influx of about 500 votes in his camp.

The convention purported to start Wednesday evening, September 21 with an icebreaker welcoming reception. Two guys, Steve Conley and Mark Wiesberg, showed up Sunday, September 18th. Steve was driving a purple Prowler and went downtown looking for us. They were having a hot rod show downtown and assumed he was an entry. He was looking for parking and found $15 a bit steep but paid it. A few hours later he had won his class, barely aware by then that he had entered it.

By Monday afternoon we had 25 people in the shop poring over cars with various problems and having the time of their lives. And it grew in intensity from there.

By Saturday evening, EVERYONE was drained and exhausted. Brandon, due to obligations with his job as a musician in Pennsylvannia, was unable to join us until Saturday afternoon.

We had an excellent dinner Saturday evening at the historic Southeast University River Campus School of Visual and Performing arts. This is a renovated Seminary originally built in 1843 as the first institution of higher learning west of the Mississippi, albeit not very much west. Actually on the west bank. In the shadow of our gorgeous new suspension bridge, it is a scenic setting for the evening meal. Chartwells catered a just outstanding smoked prime rib and baked potato. Brain Noto had cunningly provisioned the August release of Silver Oak's 2007 Alexander Valley Cabernet Sauvignon which was superb. One of the contest finalists, Mark Emon, of St Michael's Winery had also generously brought a number of bottles of their white wine which was also received with broad approval all around.

We introduced each of the ten finalists with the exception of Ralph Tate, who had scored last and was unable to attend. And we introduced Mr. Hollinger as the prize winner. Sponsors Netgain Motors, EVNetics, and Recharge Car were all in attendance.

Mr. Hollinger spoke briefly on how he got involved in electric vehicles and where he saw it going over the next few years. His address was very self effacing and modest, but generally managed to bring the entire group of 160 at dinner to tears in rather obvious manner. Mike Picard, the runner up, seemed particularly tearful.

And why was I so pleased? I spent some time talking with Mr. Hollinger at Sunday dinner at my house and indeed he spent the evening there before his flight Monday morning. This is an enormously thoughtful and intelligent young man, very much on the left side liberal end of the spectrum politically, but with very reasoned process leading to some resentment at a number of the coercive things in our society but particularly the oil/OEM/government triumvirate that would seem to keep us serfing on the fiefdom of gasoline. He's really quite determined to do something about it with regards to championing the advantages of the electric car. And while a slender musician from Lancaster might seem unlikely, the Austin FX-4 will be his FOURTH conversion.

My own satisfaction is a bit more pragmatic. The guy is good with a video camera. That's how he won the contest. Obviously we want to follow up with updates on his build and that's a bit of travel for us unless he can be persuaded to document it by video for us. And he appears to be more than capable. Take a gander:

This was all done on the run. This guy has many talents and many blessings. We look forward to what effect the award of these components will have on the future of electric cars.

Our thanks to George Hamtsra of Netgain Motors , Sebastien Bourgois, of EVnetics, and Josh Stilwalt of RechargeCar - all displaying vendors at the EVCCON as well as in attendance at the dinner. Along with Masterflux, they of course sponsored the "Build Your Dream EV" contest.

I can't wait to see, and perhaps ride in this Austin FX-4.

Jack Rickard

Jack Rickard and Contest Winner Brandon Hollinger with the Pile Of Loot

Wednesday, September 21, 2011

EVTV on National Public Radio.

Jacob Mcclelland of local NPR affiliate KRCU has kind of broken into the national story team at National Public Radio with one of his first national stories - about EVTV. Aired this morning, September 21, 2011 on NPR's Morning Edition.

Our congratulations to Jacob on getting into national reporting and our appreciation for this very timely story for us.

Our web site would be overrun this morning, but we host on Amazon's AWS service and it is very nearly infinitely scalable. So not to worry. This should spread the word to many more potential viewers. We'll see.

Using a service called WEB STAT I can actually see individual connections to the web site and how many are "online" simultaneously. I'm sitting here watch 160 simultaneous video downloads from the Amazon Cloud - a surprising number from RUSSIA and the UKRAINE. Morning Edition must be very early there.

It is a machine of beauty. Amazon's Cloudnet is bestially arcane to deal with, but a thing of beauty in operation.

The Amazon CloudFront Edge Network
To deliver content to end users with lower latency, Amazon CloudFront uses a network of edge locations world-wide. Amazon CloudFront uses the following edge locations:

United States
Ashburn, VA
Dallas/Fort Worth,
Jacksonville, FL
Los Angeles, CA
Miami, FL Paris
New York, NY
Newark, NJ
Palo Alto, CA
Seattle, WA
St. Louis, MO


Hong Kong

Jack Rickard

Saturday, September 10, 2011

EVCCON 2011 - September 21-25, Cape Girardeau Missouri

A little update on the Electric Vehicle Conversion Convention. I got the program guide done and off to the printer. Hopefully it will be printed and back in time for the convention. But I thought some not coming might want to take a look and see what they'll be missing.



Monday, September 5, 2011

Be Careful What you Ask For

Six months ago we received a request for a quick list of parts to make a B&B Manufacturing Turnkey Minus 66 Cobra kit car into an electric drive vehicle. We responded that it wasn't quite that easy. The components required kind of had to be worked out based on what you wanted the car to do and it required a bit of thought. We were more correct in this than we realized. And therein lies a tale.

I have enjoyed and endured a variety of experiences in my brief life. Racing automobiles never was one of them. Vehicles of my youth revolved around farm and construction equipment and we worked on them of necessity. They were not a lot of fun frankly. So I never got into the passion for automobiles and specifically not the race scene.

The 66 Cobra was produced specifically for racing. And it is one of the more popular and enduring replicas, usually available in kit form. An entire culture has grown up around this mythic beast. But I was learning Z80 assembly language with Rodney Zaks at the time all that was going on.

But a clean sheet design using someone else's idea of what an electric car should do might be a challenge. Er, duh, yeah.

The topic has actually come up again with the same car. The answer is the same only more so.

This week we pretty much completed assembly of the battery pack for this vehicle. I think it illustrative of how one basic design decision/component choice drives three others, and those in turn three others until you are in a quagmire of components all deriving from the initial suppositions. Be careful what you ask for.

The basics go like this. There are three factors in an electric car conversion:

1. Range

2. Performance

3. Cost.

You can optimize for two. By way of example, the little spreadsheet I keep on component costs for the Cobra currently shows $42,519.40. No labor. A bit of outside fab. But by far and away just components. And it doesn't include the original cost of the "Turnkey - Minus" at all.

The original concept involved a car that would do a true 120 mile range, 120 miles an hour, and a 0-60 time in six to eight seconds.

To do 120 miles reliably, we have to have a 100% discharged range somewhere in the neighborhood of 140-150 miles. That takes a LOT of battery to do in a conversion - which adds WEIGHT. Weight is the enemy of performance. To launch a 3000 lb vehicle to 60 mph in six to eight seconds requires a lot of POWER. In this case, I calculate about 250 kw of power.

To do this, we chose to go with a Netgain Warp 11HV motor. Why? Series DC motors are just very good at producing torque, which is what we need to launch this beast. But they are power limited by the voltage you can run them at before brush arcing occurs. The 11HV features Interpoles - windings between the field windings that are aligned so as to neutralize the induced voltages in the windings NOT connected to the brushes so when they DO make brush contact they do not arc. This allows higher voltages, and thus higher power. THe normal Warp 11 is traditionally limited to 170volts. This HV version let's us go to a higher voltage, and so a smaller current for the same power.

But not much smaller. To get 250kw, at 231volts, we have to have over a thousand amps. Of course, when you take 1000 amps out of a 231 pack, it really is NOT 231 volts any more. It's more like 175 volts. And so we're back to needing more current.

We are going a bit out on a limb opting for the reallly still beta Netgain Controls Warp-Drive Industrial version. But it purports to do 260volts (actually higher) and 1400 amps (we hope). So even if our pack sags substantially, we can still be up around 250 kw total electrical power applied to the motor.

Of course, we don't want to burn up the motor. Our best effort at avoiding that is the addition of a cooling air blower. Not all blowers are created equal. But we can get 450 cubic feet per minute from a converted Garrett Turbocharger. Unfortunately, it is $350.

We also have to cool the controller - rather substantially. So big glycol cooling system.

But the biggest wrestling match is the battery cells. We have to have a lot of them in series to get to 231volts (69). That points toward a smaller cell. But what about current? We've done 1000 amps from these basic types of cells using 180Ah cells. Could they do 1400 amps? Perhaps. For a few minutes. But 180 AH cells are kind of bulky. And as it turns out, a lot of our spaces are pretty constrained in this car.

So we opted to strap two 90Ah cells together. That gives us a very different dimension and granularity of positioning to the cells. But it also means 138 cells total.

And that drives us to a LOT of battery boxes - seven that have to be fabricated and assembled. We go to Southeast Fabricating to do the basic foldup/weldup. But then we have to add angle aluminum, attachments, lids, paint, terminals, etc. It's a good bit of work with seven boxes. Two underneath only hold seven cells each. Another two hold eight cells. Etc. It turned into a wrestling match to fabricate, install, strap up, and wire all these cells more or less securely.

Unfortunately, a LOT of these cells then pose accessibility issues. We have a two tier box in back. You have to completely disassemble, in the right order, the rear top box to access any of the cells underneath. The two rib boxes underneath are a little easier. We made little doors on the outside of the car you can remove with five bolts to expose the terminals of the cells. But many in front are likewise rather a procedure to access.

So we bottom balanced those 138 cells rather carefully,, many in the lab before installation. We tried to pair higher capacity cells with lower capacity cells to diminish the variation in capacity across the pack.

And it wound up being a LARGE pack for a car this size. It weighs in at 973 lbs for the cells, not counting boxes and straps, and provides 41,607 wH of energy storage.

But that gets us several things. First, 300 wH per mile for a 3000 pound car is about the right 10:1 ratio we see in all our cars. If you've followed the Spyder/Speedster fiasco you will now be much smarter that range is not always range and indeed it is a very ethereal thing. But we've found the 10:1 rule pretty good in practice.

The 300 wH and the 41,607 wH work out to 140 miles at max 100% discharge. 120 miles would then be 36000 wH or 86% DOD. That's a little higher than we like but we're making tradeoffs here and doing our best. It will safely deliver 120 mile range in a pretty good variety of conditions. We're hoping he charges more often than that.

So you see the game we are playing.

Second, we get our higher voltage for the Netgain Warp 11HV. And finally we get our 1400 amps, at least for a few moments. We're hoping for a full 250 kw on the dynamometer.

Speedster Redux got us 147 kw in 2385 lbs for 62 watts per pound and does a zero to sixty in 6.5 seconds. At 3000 lbs, that will require 186 kw. But frankly we are hoping for some upside at 250kw, if we can pull it off. And there's a lot of slips between here and 1400 amps.

Of course, to handle that amperage we have to have a kind of massive high current relay. We took two fairly ordinary ones and coupled them together. In doing so, we hooked up quite a bit of copper plate to help dissipate the heat.

As to cable, the choice at these currents is between 2/0 and 4/0. The 4/0 would be better, but it is heavier. MOre to the point, it is harder to work with. With seven battery boxes, that's a challenge. And since we don't have any very long runs connecting all those boxes, we opted for the 2/0.

To keep the noise/EMI down, we have gone with Champlaign Cable Company shielded cable designed specifically for electric vehicles. Unfortunately, it's also designed to fetch $8.57 in ducats for each linear foot of the cable.

To fuse all that current, we use a Ferraz Shawmutt A30QS800-4. This part number indicates a 300vdc rating and a 800 ampere rating. It's not precisely a slow blow, but it will take 1400 amps for a few seconds.

As to a high current relay, we faced a bit of a problem. We used two of the Tyco Kilovac EV200 relays. The proper relay for this is probably their EV500 series, which will do 1600 amps for 10 seconds.

But the EV500, called "Bubba" is typically available for $1200 to $1400. Occasionally they come up on eBay at $350-$500 each. But the EV200, rated at 500 amps, are common as dirt at about $70 each. So we used two of those in parallel.

The current capability of the EV200 is kind of dependent on the size terminal lug connected to it. The terminal lug actually acts as a heat sink. So to do the advertised 500 amps, you need a pretty largish lug and cable. While we're ok there, more is better. So to parallel them, we actually used a pretty hefty piece of copper bar stock. This should help dissipate heat and allow our pair to do 1400 amps briefly. We'll see. At $140 instead of $1400, it's worth a try.

On the other end, we spent a couple of grand on lighter wheels and low rolling resistance tires, which did save us 10 lbs each on the front and 16 lbs each on the rear for 52 lbs. We also spent $1120 on an aluminum third member for the differential. Again, the weight savings was substantial

The result is our car is 32% battery by weight. But the components to do it would total over $42,000.

All of this from a couple of basic assumptions regarding what kind of car we'd wind up with. Had we said 11 seconds 0-60, and 80 safe miles with 100 miles to 100% DOD, we would have a much lower weight and cost and a much easier time fitting battery cells.

My experience with these cells comes out the same way every time. They want to make a car with 100 max 80 safe miles. Yes, you can get them to do more, as we have in Redux and now Cobra. But it grows exponentially more difficult and more expensive.

The question you have to ask, is what do your REALLY need and want in an electric vehicle. Everything in design is a tradeoff. There are no little easy answers. I can't give you a "kit list" until I've done the design and build, tested it, revised it probably several times, and so forth.

Will a go fast Cobra with a 120 mile range scratch the itch? Let's hope so. But be careful what you ask for.

Jack Rickard

Friday, September 2, 2011

Testing, two ... .three

The online milieu offers enormous opportunities for learning and information about topics of interest. In the early dreams of a global internet, this ability to pool the expertise of many individuals around very narrow topics of interest was one of the greatest boons foreseen. Unfortunately, in many ways it has turned into a cesspool.

There are a number of people out there successfully converting electric cars. I am disheartened to observe that the majority of them view anything they learn along the way to be a "proprietary secret" they can somehow leverage into untold riches from their little shop in what they see as a viciously competitive world.

Well, if you see it that way, it is that way - for you.

That mostlly leaves the online forums as a source of info about electric vehicles where roving bands of clueless people copy/paste what the last guy said into the next conversation - with a few typos and often some expert opinion on what it really means. This leads to comically large bodies of total disinformation misleading anyone who reads it into believing it is real. The pool of knowledge becomes a cesspool.

We attempt to counter that in two ways. First, we actually DO build electric cars, and we share all of it with our viewers. The good, and too often the embarrassing bad. To get the most from it, you have to watch over time unfortunately. The neat device and grand theory as to why that's just the tits in this week's episode may be followed in six months and a few thousand miles by an examination of the charred pieces and a rebuild using something else. Real world. I should apologize for it.?

The second prong of our attack on disinformation is to actually DO testing, not just talk about theories we've heard. And better yet, to demonstrate how to DEVISE tests you can do to learn first hand yourself. We encourage others to also perform our tests and report their results = either confirming or contradicting our findings.

Part of this goes again to the 12 blind men around an elephant. Corresponding about IDENTICAL cars, for example with Eric Kriss who basically built Speedster Duh, can be quite frustrating. Different results from two identical cars? Or maybe not so identical. And maybe not exactly the same test conditions... you see the problem.

Part of it is contrast and comparison. Most people don't HAVE two vehicles to compare. Indeed, often you have NO other frame of reference at all. You build your first electric car, and often take your first electric drive in it. Does it feel like it's supposed to? How IS it supposed to feel?

Our first car was the red speedster of course. It ran flawlessly. Oh, I guess I was a little disappointed in the performance. But it certainly kept up with traffic and was pleasant to drive.

Six WEEKS later, I was playing with the Kelly Controller software and noticed the minimum battery voltage setting. I see that voltage a lot so I must be at minimum voltage a lot. I wonder why?

I changed the setting to a lower value. Instead of 100v for my 108v pack, I lowered it to 90. Reset the car and hopped in for a drive. Backing out of the driveway in REVERSE I very nearly shot through the fence around the property in an almost uncontrolled acceleration. I immediately stopped the car and checked everything again. I reset the voltage to 100v and the car behaved quite normally. I changed it back to 90v and VERY carefully applied the accelerator. The car shot ahead like a rocket (comparatively speaking).

When the controller notes the battery voltage approaching the "minimum voltage" it cuts back current to the motor to prevent the pack from going below that voltage. Of course it does this several hundred times per second. As a result, when I applied throttle, it put out power to the motor until the voltage dropped to 100v. At that point it limited current to precisely the value necessary to hold 100v. If the voltage crept up, it increased current. If it began to sag below 100v, it would decrease current. And it did this so well, it felt quite smooth. The car operated flawlessly, at about 1/4 power.

The batteries DO sag in voltage when you put them under load. So by decreasing this "minimum voltage" all of a sudden I could get full power out of the device.

While this is almost comical, it illustrates the problem. No frame of reference. I might have gone two years before discovering this. Never really gotten excited about electric cars, which felt pretty tame up to that point. And so never shot our first episode - no EVTV. For want of a nail....

So I'm very sympathetic to the guy trying to build an electric car with no "go-by." No frame of reference or model to build too. It is ALL a discovery process.

We did this comparison between the Speedster and the Spyder largely as an exercise to demonstrate some of the components of range and specifically the impact of aerodynamics on range. Whey you get one range at 45 mph and a very different one at 75 mph.

But real world testing, as opposed to staged scripted test demonstrations, always have outliers and anomalies. In this case a huge one. A very marked difference between two cars with ostensibly identical drive trains.

The problem was that the aerodynamically slightly pudgy looking 356, which was also 200 lbs heavier, got DRAMATICALLY more range than the sleeker and lighter Spyder 550. And everything we tried made the disparity more pronounced.

We spent $3100 on running gear upgrades using really kind of extreme aluminum rotors and calipers, low rolling resistance tires, lightweight wheels, and indeed shaved some 60 lbs from the car, dropping the curb weight from 1905 to 1844 lbs.

Of cousre, we also learned that the Michelin Energy Saver A/S low rolling resistance tires on the Speedster weren't set to 42 lbs pressure as we thought, but a more squishy 33-34 lbs. When we aired the tires up, the Speedster got dramatically better, as good as 1.000 AH per mile at 40 mph steady speed. That's a 180 mile range.

Meanwhile, all that work on the Spyder produced improvements, but improvements so meager they are almost in the noise level of the test.

ENter by far our most popular test technique. The Soap Box Derby. We've received so many comments on this test that we are thinking of incorporating it into our race day at the Electric Vehicle Conversion Convention (EVCCON 2011) I'm searching for some kind of incline or ramp we can use. In addition to the electric AUTOCROSS RACE and the electric DRAG RACE we have scheduled for Friday afternoon, I would like to have a SOAP BOX DERBY where we can see who's car rolls the furthest at 2 mph.

The Speedster will pretty much roll down the street pretty nearly to the house in neutral. The Spyder almost goes into reverse and backs up the hill. It barely moves at all.

We received a lot of input from viewers on this. My favorites suggestion came from John Hardy of the UK. This involves some residual pressure valves in the brake lines. In cars where the master cylinder is below the calipers, the brake fluid of course has a tendency to drain back down into the master cylinder and you have to pump the brakes to get the fluid back up into the brake calipers. On drum brakes, the wheel cylinder holds much more fluid than disk brakes. And these cars were all originally equipped with drum brakes on the rear, disk brakes typically as an upgrade.

So to keep the fluid from flowing back, they use a little check valve that maintains just a bit of pressure on the line to keep the fluid from flowing down by gravity. On drum brakes, this residual pressure valve typically provides 10 ps, while for the lest voluminous disk brake calipers, a more modest 2 psi. John's suggestion was that they had upgraded the rear brakes to disk but kept the 10 psi residual pressure valve from the drum brakes. This causing the rear pads to drag.

I loved it. Our master cylinder IS below the calipers and we don't have to pump the brakes so we must have that.

We went through the car and can't find one of these residual pressure valves anywhere, front or back - or of any value. But it was a GREAT theory.

We had the car aligned this week. I haven't' retested yet but I would be astounded if that made that much difference. Perhaps. But we did reroll the Soap Box Derby and no joy.

Several viewers have commented on the negative camber on the Spyder. I think it is slightly more visible on the Spyder. But all these cars have negative camber - the book is 2 to 5 degrees. The Spyder is more on the 2 degree side actually.

About all that is left that is obvious is the difference in the Ring and Pinion gears - essentially the "differential" on this car. The Spyder has a 3.88:1 and the Speedster has a 3.44 to 1. Eric Kriss spoke to a racing transmission expert who claims that could indeed do it. So it's our main culprit at this point.

It is unlikely that I would swap out the transmission to find out. The car runs nicely and has a 100 mile range now. But we will certainly stick to the 3.44:1 for future builds.

You always get a result from testing. But in the real world, often it can be weeks or months before you really know what it all means. Aerodymics still has the predicted impact on range. But why these two cars are so very different is so far beyond me.

We have a new Canon AHX1 camera we're trying out. It has built in XLR microphone inputs but we apparently did not adjust our audio very well because it is truly awful in this episode. My apologies. Testing, testing.

Jack Rickard