Locost-Style Super High MPG Commuter Ideas...

My brother built a Volvo B20 powered Locost and had been dreaming about doing another one with electric power only--kind of a Colin Chapman golf cart kind of thing.

Then we were having a conversation about how the auto industry can't seem to make a real dent in the gas mileage wars. Even the super efficient cars like the NA MINI, the SMART, the Prius, etc. all fail to really improve on the 1989 CRX HF. Is that the best we can do in 20 years of development?

We then talked about taking a CRX HF and putting MegaSquirt on it. Then the idea came up of doing a 3D GPS system that could be linked to the MegaSquirt to lean the thing way down on downhill segments. It may or may not actually work, but the idea is that there should be a way of getting to 60+ MPG, right?

Then we started thinking about taking the Locost ethic and skills and putting it towards something more radical.

The idea would be to do a survival cell for two passengers (front and back, motorcycle style) in 1.5" tubing, and then build the rest of the frame in something closer to half inch tubes. Make the body out of aluminum panels and fiberglass, and power the whole mess with....

Well, good question. It would have to be small. This "car" could be slow, but it should go 70 MPH to actually move with highway traffic. I was thinking something like a water-cooled motorcycle twin cyl engine. Maybe a Ninja 250 or an EX500? I know that a Ninja 250 gets around 70 MPG. I don't think this is worth doing if we can't get to north of 60 MPG.

VW claims over 250 MPG with a single cylinder diesel. I am unclear on where you would source that kind of powerplant. Is there a high efficiency diesel twin out there that could work?

I know this is nuts, but thanks for dreaming along with me. Beats working...

Aaron

You may want to use these guys as a starting point: http://www.edison2.com/

Turbo'd 250cc motorcycle engine, runs on E85.

Mother Earth News once built a Locost with a small Kubota diesel tractor engine. About as fast as a stock MG Midget from the smog era, but it could keep up with traffic. They said it got around 80 mpg, and last I heard were putting a more aerodynamic body on it to see if they could crack 100.

for some reason, it reminds me of a Messerschmitt...

i seem to remember hearing about a company called monster diesel or something like that that makes diesel engines that fit into motorcycles. crazy mpgs id imagine. also, you could source one of the old n/a diesels out of a rabbit/caddy. those got like 50 highway in rabbits and caddys, im sure much much more in your areo-liteweight-efficiency contraption

The only thing that I have to add is be very careful about safety. If you want it to be safe you'll either build a rollcage and require helmets and 6 point harnesses (not a bad thing, I suppose) or taking a flying guess at what constitutes a crumple zone and how it will actually behave in an accident. That science is really quite tricky. I'd go the rollcage route - maybe you could place the bars far enough away that you could skip the helmets, but that's my main concern. Of course, if you're okay with the safety on a motorcycle, then you're probably fine.

Other than that it sounds doable. They can't make a dent because nobody would want to buy the thing you'll end up with. It won't handle, the seats will be light aluminum racing seats, it would have bluetooth, navi, heated headrests, espresso makers in the dash (his and hers) etc... I'd probably buy one though.

If somehow you had access to a full copy of Solidworks, it would make the project much easier becaus you can do impact stuff for the survival cell and CFD for the aero stuff. But it is kinda expensive.

I'd be very wary of trusting the AFR of my motor to the strength of my GPS signal. If you want to lean it out on downhills, why not just use something more low-tech that's less prone to failure, like a simple mercury switch? This'd also give you the advantage of "intertial tuning", where acceleration would keep the mercury more in the "uphill" position, and deceleration/braking would push it more into the "downhill" position.

MadScientistMatt wrote: Mother Earth News once built a Locost with a small Kubota diesel tractor engine. About as fast as a stock MG Midget from the smog era, but it could keep up with traffic. They said it got around 80 mpg, and last I heard were putting a more aerodynamic body on it to see if they could crack 100.

I remeber this build. Very cool!

The problem, as I see it, with this sort of build is that the line between car and motorcycle becomes very blurred. At some point, the "car" becomes just a very slow, funny looking, 3 or 4 wheeled motorcycle. And then you've potentially lost the advantage of the car, which is carrying 2+ adults in comfort, with room for groceries and other stuff, while not being as fun to drive as a motorcycle.

Also, the emissions of the thing become an issue, especially if you decide to use a somewhat agricultural engine (such as an older diesel). What matters most out in the country is carbon emissions, which is more-or-less dictated soley by MPG, but in more congested areas (where a car like this would likely be popular) the other pollutants become more of an issue. Then you're talking all sorts of fancy tech to clean the engine's outspewings, and that takes more technology, more cost, and more weight.

Personally, I would love a car like this, and on an individual basis, I think its a great idea. For mass consumption, though, I'm simply pointing out some of the perils that are having to be dealt with. BTW, LoCost with a B20? Cool! (DD is a '67 Amazon wagon with a B18, LeMons car is a 2-door with a B20)

When going down hill, why keep the engine running at all? You don't need it. Heck, on many deceleration, you can turn the fuel off.

Oh, and we've been doing that for a couple of decades...

As for lack of improvement- the most important problem is that not enough bought the plane gas cars that got great mileage- both the HF and the later Civic EX were not strong sellers. And if nobody buys them, there's little incentive to make them.

Also, for at least the HF- emission rules have changed a lot- so it's lean cruise mode would not meet current NOx emissions rules (I'll have to look up how bad they were).

Lastly- the current market really doesn't much support cars that are that slow anymore. I know that sounds odd, but it's pretty true- people tend to over buy their performance needs, even if they never drive that way. It's funny to see so many people accelerate slowly, but not want slow cars....

shrug...

Eric

(oh, there are some interesting glass bodies out on e-bay I've seen. many will fit over a locost body - weight and aero are key- but you know that already....)

Despite the relatively steady economy numbers fro cars the specific efficiency of modern engines has really improved over the last few years, Unfortunately all the gains go towards compensating for the huge mass increase of modern cars...

I believe quite a few new cars stop injecting fuel into the cylinder when the detect they are in a compression braking situation. This would actually be a pretty easy thing to detect. for example you may be able to get away with shutting off fuel to the cylinders when the Throttle position = off, and rpm > ~1500

I like your idea...

BTW, Having had some experience driving older, efficient Hondas that were somewhat slow-ish, I sort-of came up with the idea of sticking a 1.5 liter d-series workhorse honda plant into something like a replica vintage Porche body, total weight around 1500 lbs and with ~100 hp, it'd be respectable in the performance department. Crashworthiness, well....

OP, something like this?

http://www.wired.com/autopia/2010/08/student-built-ev-defies-the-odds-may-break-a-record/

I had always wondered about doing a 7 clone with a diesel engine.

The reason is pretty much what Eric said: remove performance, safety and emissions requirements from the equations and fuel economy becomes much easier to engineer.

This is sort of the thinking behind the pending TDI kit car. With an older TDI, emissions requirements are nil and since he's reusing much of the original MkIV chassis, there will be some safety engineering built in (although from what I've seen thus far - not any better than an Elise).

Am I the only one who thinks some of the regulations are a little nutty? I would have thought they would want to encourage fuel efficent vehicles. I mean, safety is great and there should be very safe options available. But here in Colorado I can ride a motorcycle with no helmet, but I can't buy a car without an air bag. That's just kinda... well.

I was going to build an electric for my 3 mile commute where I never go more than 35 mph, but just too many projects and not enough time.

One other thing- if you are anywhere near 96CivicDX- you need to sweet talk him into dumpster diving.

Two things- carbon fiber- and (more importantly) scraps of honecomb structure. With the proper bonding, you can create the center section of a locost with honeycomb (carbon, kevlar, aluminum, whatever) which will be lighter (stunningly), stronger (duh) and safer (honeycomb fails in a rather nice way for crashes). Basically, it's elementry sports racing car construction with aircraft scraps. Pretty straightforward construction, too.

Then it's a matter of a light weight body to cover it all along with a tube frame front, and some kind of something for the rear.

I've always thought that copying an Lotus Elise in basic body is a great idea. Imagine putting an HF or TDI powertrain behind the driver+ a super aero body. There are a TON of games you can play with a mid engine set up for a super high milage car. Especially if you keep ALL of the heat behind the main structure (better for adhesives).

Basically, you have a GRM version for the X-challenge.

I'd be happy to keep throwing out ideas

Eric

alfadriver wrote: Basically, you have a GRM version for the X-challenge. I'd be happy to keep throwing out ideas Eric

Perhaps that could be a good addition to the GRM challenge- how far will the vehicle go on a set amount of fuel. Or, how much fuel does it take to drive a set distance- that might be easier to figure. Hey, fuel economy is more or less just as valid a performance metric as an autocross or a drag race time.

wouldn't be the first time we thought of it.

For that matter, the last time we had an X-Prize discussion, we brought it up, and that was just a few months ago.

It would be easy to set up a TSD where there was a min and max time window where you could finish- easy to follow, long enough for a decent measurement, but not so long to break bladders.

But I suspect it would have to be yet another personal sub challenge. Come up with a trophy, and I bet Per would be happy to give it out.

Eric

Drewsifer wrote: I had always wondered about doing a 7 clone with a diesel engine.

Been done already. I don't have the links, but try googling san francisco las vegas bio diesel seven or something like that. Guy on the Yahoo Locost List did it. There were some newspaper articles on it. It was an alternative energy contest. The rules were they could leave with a full tank and had to get to Vegas without buying any fuel. He had people donate waste vegetable oil along the way. He was the only one to make it. Actually, I think he was the only one to make it out of San Fran. Just drove on over. I think he got like five large as a prize or something.

fast_eddie_72 wrote: Am I the only one who thinks some of the regulations are a little nutty? I would have thought they would want to encourage fuel efficent vehicles. I mean, safety is great and there should be very safe options available. But here in Colorado I can ride a motorcycle with no helmet, but I can't buy a car without an air bag. That's just kinda... well.

It's because regulations are written with regards to percentages and there are way more cars on the road than motorcycles. Not that I don't think riding w/o a helmet is idiotic... No helmet law in PA either...

It would be cool to see a fuel economy test as part of the $2010 challenge - that would even the playing field for some of the cars with less HP...

I think Jack McCornack's MAX is the diesel Locost referred to above.

Click on the 'X' next to the date to delete double posts.

Yeah, Jack's Diesel Locost. That was it.