Coulter's Smithing Home


It's the car, stupid!!!

This project is more or less the opposite of the T-Bucket, despite a certain similarity in appearance. What we're going for here is to demonstrate that millions of dollars of research are not required to have a practical commuter car that gets hundreds of miles per gallon. There seems to be this vague but widely held idea that if the government just spends some more money on it, preferably money taken from the oil companies (which of course comes out of your pocket anyway, seems the sheeple never learn), that some day soon there will be this little black box you can clip to the radio antenna on your toyota and it will then burn freely available hydrogen, or something like that.

This is not going to happen for lots of sound scientific reasons. The biggest single one, rarely mentioned, is that fuel cells need platinum to dissassociate the H2, and using a monomolecular layer, as current technology allows, all the platinum on the planet would only make a few thousands of cars. Doh! Don't think that plan is gonna work for the Chinese and Indians anytime soon, or even our far smaller population in the US.

Our design philosophy is in bold above. We don't need new tech here, just a new outlook. If the car is easy to push, currently available technology will push it with minimal fuel and very little pollution. Yes, a tiny, light vehicle is not as intrinsically safe as an SUV for example, though this thing seems nearly impossible to roll over. That same SUV is a big loser in a crash with a tractor trailer or loaded pickup truck just the same as this would be toast in a collision with a normal car. We'll just have to drive it carefully. It's a lot nicer at any rate than a motorcycle as far as safety (and comfort) goes, and that is a chrome-moly roll cage and frame, like a NASCAR vehicle. Your car doesn't have a frame, but mine does. We'd thought about making this a hybrid from the start, but due to the engine/weight ratio, we'd not gain very much that way. The engine is always working at near full power, where it is most efficient, so added weight for batteries and a motor–generator would only lose efficiency. On the other hand, something this size would be a good candidate for a pure electric, which we could charge from our PV panels here. We'll see where this winds up! Comments appreciated!

Cart as bought Here we see the thing as delivered from Northern Hydraulics. You can see plenty of extra gingerbread on the front, which we will be removing, as well as the package tray on the back that doesn't show in this picture. We also checked those bucket seats, and they weigh on the order of several times what a normal car seat does, as well as being too high and too far forward for adult humans. So, the first step is to strip off all the extra weight and other dumb things in preparation for putting a body on her (this seems to be a girl car, rather than a boy or an it), and a real seating arrangement. I can barely tolerate the seatbelt harnesses, and will leave them for now, even though they have a nasty projection right behind your neck for a bolt that'd kill you in a crash.

Specs from the service manual:

Weight: 341 lbs dry
Power: 9 Hp from a 150cc 9.2::1 compression bike type engine
Fuel tank: 1.54 gal
Wheelbase: 57 in long, about 47 in wide (front and rear are different)
Brakes: All wheel hydraulic disks
Steering: rack and pinion
This is not the kind of go–kart Doug grew up with, to say the least. Those were pretty miserable, especially in brakes (keds!) and handling. This is pretty nice as is.

Doug used to be a serious motor head, so we can bet that 9 hp figure won't be true for very long. Neither will the weight. After stripping off the junk and putting back what we want, we should be about even there, but might gain or lose a bit. The stuff we're taking off is heavy after all, and the things we're adding are not so heavy, except the windshield. At its current 38 lbs/hp, it is surprisingly peppy up to about 30 mph, when the CV transmission runs out of ratio. We seem to be getting about 50 mph top speed on the flat with current gearing, but that is one thing that will be changed. The current limit on speed isn't power, it's engine revs. No need for this to be able to climb 45 degree slopes, as it currently will. Gas milage is in the "great" category, but until we do some measured runs, can't be stated here yet. Got to replace that picture of an odometer on the dash with the real thing to measure it easily. One can drivethe thing all day long without running it out of gas, though.

Excess weight removed There was a surprising amount of excess junk associated with this kart design. We found the gingerbread on the front especially annoying, as it seems designed to push the steering column through the driver in the event of a crash. We'd rather have at least a little crumple zone instead, which we now have, though the floor steel is still somewhat too thick for that. The package tray was a lot of extra weight, and placed high, raising the center of gravity. As it was also the gas tank mount, new small brackets were fabricated to replace that function and powdercoated. There seems to be an amazing amount of steel in those bucket seats. Normal auto seats are a thin skin of foam over some thin springs. Not these, which take more than one hand to lift. At any rate, due to fit issues, they place the rider too high and too far forward for comfort if the rider is a normal sized adult. So, out they go, and we will replace them with a more comfortable bench seat made of foam and fabric, which won't have to be rock hard, like the buckets are. Not shown in this picture is one of the rear springs, which was removed to get the spring rate correct for the reduced weight. We will be looking for new coil-over shocks for the back end to make a more permanent correction to this problem. The way it was, the rear suspension was at its upper limit even with Doug jumping up and down on the driver area. Rides better now, to say the least.
Getting started on the body Here's the cart in the shop. The polycarbonate windshield is so clear it is hard to see in this picture. The motor in the lower right is what we would use to make it all electric, if we go there. The tires on the floor might get modified to match the wierd bolt circle the cart uses, which is of course different on the front and the back. We'll save the old tires for off–roading, but are seriously in need of wheels and tires that say "DOT approved" on them. The windshield is pretty heavy, being 1/4" thick polycarbonate. For the first attempt 1/8" plexiglass was tried, but I wound up wearing that and the bird I hit at top speed, so we went to better stuff. We are using mostly 22 ga steel for body parts that aren't plastic or wood. No additional strength appears to be needed, just a way to keep the wind, weather and high velocity bugs out. This drives very "tight", no flex or twist is noticeable. The center of gravity is just at the back of the seating area, in the middle. If jacked up there, all 4 wheels come off the ground at once; sort of handy to be able to twirl the thing around while working on it.

We are finding that this goes faster at lower throttle as we are adding things to it. The best guess is that it is becoming a bit more aerodynamic. It will never be as good as the current crop of teardrop shaped autos, as Doug and the rest of the crew aren't into serious compound curves in sheet metal, but it is so small things work out anyway. We are looking into reducing the ground clearance somewhat to see what effect that has. Right now it is more than needed for a road car (over 5"), and may have air rotors or other turbulence going on down there that slow us down. Current day autos and especially racers have an air dam there to keep pressure from building up under the car for this reason.

The price is right! Doug could not resist putting this picture up here, with helper Anna Corder doing her best Bob Barker pose as a goof. Anna did the seating, and did a darn fine job. A 6 foot normal human now fits without any cramping, and it's comfortable with extra lumbar support. She likes driving this thing too, but is really looking forward to it having a heating system, as it is beginning to get chilly here in the mountains. We think we can take off the engine cooling air for that function. Doug got some super bright led arrays from DigiKey for turn signals, backup lights and so on. These are Lamina Light Engines, and they are so bright as to be scary -- looking into one for a fraction of a second produces serious afterimages. We won't have trouble with tailgaters once one of these 350 lumen lights is turned on. Expensive ($24 ea or so right now), but worth it. We'll probably have to use a variable dimmer to make them truly correct for the job. That way we can just turn them up to blinding when there's a problem being noticed.

You can see the paper template we are using to see what metal would look like put into the same place, as we want to keep the cute factor alive here. We've painted some of the metal, some with car paint, some with powder coating. The piece of wood at the back will have to be replaced with clear or tinted plastic to allow backing up in close quarters; you live and learn. Soon it will be hard to just stick your head out the side to see, and that's one of the cut and try things we are finding out here. Though not shown in this picture, Doug has added a tailpipe south of the muffler which really quiets the thing down without noticeable power losses. We are working with various panel resonances as well to get this thing acceptably quiet in use. The main trouble spot at present is the windshield, which goes into resonance right at the engine torque peak, yuck. We might have to put a non– transparent bar across someplace to help control this one. The metal parts are no trouble so far, with undercoating and carpet glued on to them. The observant reader will notice that we've already gotten a county tax sticker on this. That part was easy, all they need is money and maybe a VIN, which this actually did have. Safety inspection needs all the usual stuff, which we want anyway, but the State (VA) is going to be the real bear, as the state vehicular code is obtuse, spread around a few million pages of other law, and basically is set up to make things easy for big guys (think a million dollars for crash and pollution testing if you don't already own a certified lab) and impossible for innovators. This we plan to have changed. What politician will want to go on TV to explain why he is supressing the used to be mythical, but in this case, actual, 250 mpg carburator at these fuel prices? The news anchor and state cop are lined up already. As are the crowds for witnesses and support. It can be nice to live in a small town...

We are now trying to figure out sides/doors for this. It's hard enough now to climb into and out of, although a 300 lb friend can manage it, and there's that cuteness factor to preserve. Gull wing doors have been proposed, as have canvas/sailcloth ones like some jeeps have. We will need sides as wide as the widest part of the back at least for most of the passenger area, as knees and elbows now tend to protrude past the little nerf bar thing when the riders relax. This is probably going to take a few iterations, during which we'll generate all sorts of nice information on what doesn't work. And oh yeah, we need that driver's side rearview mirror mounted somewhere visible to be legal. Thanks to the guys at HMI (where we get our welding supplies and propane) for donating a nice mirror!

There will be a lot more up here as we make progress. This is currently our number one priority, as we want to strike while the iron is hot and the gasoline prices are high. We sort of expect there will be at least another price glitch soon, and we want to be ready for that to get the maximum effect on the politicos. Comments are welcome and requested. If anyone out there has gone down this road, please be in touch and tell us some techniques that will save us work and time on this project. Note, we are not trying to compete with hotrods by Boyd, the VA tech solar racer, and other things of those natures that will never be mass produced. This is intended to be REAL! Yes, we know a ton of ways to cheat and get tags on this. But those ways only work until there is a crash and the insurance company finds out, and so forth. We want to make something that can be produced and sold, and be totally legitimate legally. One of our old consulting customers just happens to have this huge factory with lots of metalworking equipment...

Coulter's Smithing Home

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