Automotive X-Prize: "The Very Light Car" (also very aero) with conventional engine
 

Alerted to this via ABG:

http://www.blogcdn.com/green.autoblo...ight-car-7.jpg

(You know you're an EcoModder when you show the rear view first :))

The company, Edison2, is located in Lynchburg, Virginia, and ruled out an EV drivetrain primarily due to the weight of batteries.

We don't have any details on the weight or CdA, but they're dealing with an order of magnitude change in some areas on the weight side of things:

Here's the drivetrain. Anyone recognize it? Looks to me like it may be a motorbike engine:

http://ecomodder.com/forum/attachmen...1&d=1263415230http://ecomodder.com/forum/attachmen...1&d=1263759499

Source: Edison2: The Very Light Car (X PRIZE Contender) - Gallery - The Very LightCar

Space frame:

http://ecomodder.com/forum/attachmen...1&d=1263415230http://ecomodder.com/forum/attachmen...1&d=1263759499


Unfinished body shell:

http://ecomodder.com/forum/attachmen...1&d=1263415265http://ecomodder.com/forum/attachmen...1&d=1263759499

ABG called it a "poor man's Aptera". Not very nice! (Probably not true, either.) Coincidentally, there's an Aptera in the left side of the above photo.

Web site: Edison2: The Very Light Car (X PRIZE Contender) - The Very Light Car

i want it.

Edison2 Very Light Car
 

Hi Darin,

Ya beat me to it:

This car has come a long way since the last one we saw -- it is very similar to the Aptera 2e in some obvious ways, and it quite different in other ways.

http://www.blogcdn.com/green.autoblo...ight-car-3.jpg
(click on picture for link)

http://www.blogcdn.com/green.autoblo...ight-car-2.jpg
http://www.blogcdn.com/green.autoblo...ight-car-7.jpg
http://www.blogcdn.com/green.autoblo...ight-car-8.jpg

The similarities are: streamlined body with outrigger wheels, and two seats side-by-side, composite construction.

The main differences are: ICE-only power train, 4 wheels, 1 entry door.

I like parts of this, but others are a bit odd. So, what do you think?

Nice, aero, small engine, it should be able to do a long hiway trip more efficiently than any hybrid. Low weight might make it competitive in the city too.

does the driver door swing up like a delorean? ..or like a lamborghini?

I was wondering how they made the suspension work within those fixed aero struts -- here's what appears to be the rear suspension:

http://www.edison2.com/picture/rear%...tureId=4066690

The shock sits closer to the car, and the top is braced on the chassis. I guess that there are two large diameter bearings on the inner end, and the whole tube rotates as the wheel moves up and down? They seem to not be showing the outer swing arm? This set up bothers me -- there must be a lot of torque and bending on this tube...

And I also like the "very light wheels":
http://www.edison2.com/picture/our%2...tureId=4066689

Darin, that engine certainly looks unique -- there is a heck of a lot of plumbing! It also looks to be a turbocharged 2-stroke?

Not sure about the door. Might check their gallery: Edison2: The Very Light Car (X PRIZE Contender) - Gallery - The Very LightCar

One thing I noticed: doesn't seem to have any (conventional) suspension.

They are not revealing the key spec: how much does it weigh?

It has an extra wheel.

lol, it has two extra wheels for that matter, but I still like it :)

where's the tow hitch?

I haven't nailed down the base engine, but it appears to me to be an OHC 1 cylinder turbocharged 4 stroker; could be from a motorcycle or atv. There is something funky going on with that turbo on the compressor side I don't understand yet.

Back in '82 Pa got a Honda Big Red 3-wheeler. IIRC the single was 200cc. Back then I thought that engine and trans would make a PERFECT road vehicle drivetrain!!!

I'd imagine this engine to be 200-500cc.

I don't like what I see re: rear suspension; from what I can tell both rear wheels HAVE to go up and down in unison, making them far less forgiving of different side-to-side bumps and undulations than even an old school live axle on leaf springs. Ride quality will suffer especially vs if they'd used a single wheel in the back.

Edit: Ha Ha, that'll learn me to open my yap before looking at all available info! :rolleyes: My above comment was made after looking at the still pic of a rear axle on their site. Looked to me like it spanned the rear; it was the whole thing. NOW I see from the video that there are two of them. Damn but that thing has wide tracks! Incidentally, it sure sounds just like an atv to me... Carry on...

Outside of perhaps this induction thing I don't get, I don't see anything earthshaking as far as new. However, that's not to say I don't love it!!! :thumbup: Were I to enter the X-Prize or even just build my own, they are using the approach I would have. Except I wouldn't put that 4th wheel on there unless the rules required it.

I'd rather have this than an Aptera. They've waved too many red flags already, they have the taste of scammers, almost Palmear-like. Plus their proposals are too expensive for what you get.

I assume you are scratching your head over the large tank like thing on the left of the live foto? looks like some sort of accumulator? Or a diversion?

re suspension, the rear (swingarm) suspension looks like the triangular transfer case gets bolted to the end of the tube so each wheel would be independantly sprung. the springs look like they are inboard on the "kuttner behind the wheel" photo

The front suspension is a bit of a mystery: the tube appears to be solid all the way across, but whatever is behind the wheels is not visible. If there is any suspension at all, it would have to involve a trailing swing arm, and combining this with steering would seem to be awkward...

http://www.edison2.com/picture/dsc_0...tureId=4066696

I only see one spring/shock for the rear axle assy. :confused:

I don't get the "accumilator" nor anything, really, on the induction side of the turbo. :confused:

Regardless, this is my favorite entry so far! :thumbup:

These guys give me the impression of rejecting gimmicks and are grounded in sound, tried 'n' true engineering. Yeah baby! :thumbup:

Post 14: in that pic I see an atv plastic gas tank and a cooler, presumably a turbo intercooler. I don't see the wierd stuff of the lab engine.

Front suspension/steering is a mystery to me too. :confused:

OK All four wheels are on short trailing arms; I suppose it is possible for there to be torsion springs in there too, in addition to the coil spring/shock, but that doesn't seem likely.

If I had to speculate on the suspension I'd suggest it's a trailing arm using the beam's torsion (or a separate, interior beam's torsion) as its spring. The beam itself may not be fully circular, lending a plane on which it can resolve torsion. That doesn't resolve the question of damping however, maybe an internal fluid shock? Possibly some trick of mass, where the whole assembly is so light that it can't pick up any road harmonics at any realistic speed so a fluid damper is almost unnecessary?

FYI, the engine image in post 1 is an attachment (because their site wasn't reliably serving the image as a direct link - hope they don't mind).

The original image is called "early engine simple but good.jpg"

Well, I'm a poor man. ;)

How much is the cost ? I didn't see it on their site.

Hello -

It reminds me of this :

http://ecomodder.com/forum/showthrea...ebay-8241.html

Did someone save some pictures of that trike? The ebay link is dead. Both designs are by engineers for engineers.

(note: I say EV1 in the next paragraph, but maybe I am talking about the Impact concept prototype).

When the EV1 was being developed, the Aeroviroment engineers created their own versions of the EV1. The GM car-designers were horrified at what they saw, but were designing terrible cars from an aero-POV. Eventually they came up with a design that *worked* for both sides and was closer to the Aerovironment design.

I have a hunch that the Aerovironment fellows came up with proposals similar to this.

CarloSW2

There are a few at the bottom of Bens blog

HyperRocket: 125 mpg, 100+ mph 3-wheel motorcycle | Hypermiling, Fuel Economy, and EcoModding News - EcoModder.com

I'm having more questions about this "Very Light Car":

What is the transmission? With a (very) small displacement ICE, you'll need a pretty sophisticated many-geared transmission. They show a clutch pedal...

The side intake(s) are for engine cooling, and I think the rear (oval) vents are for the heated air to exhaust out (I think?). Are there any provisions for cabin ventilation? (Obviously, there is no A/C.)

The front suspension remains a mystery -- maybe it is torsion bars inside the support tube struts? Is the steering rod also inside there, or is it behind it?

Does this car have a version of Stop/Start?

How much does it weigh?

Lol, you mean like an ignition switch with predictive logic attached? :)

dunno, they said the rotors were 1/5th the weight of standard rotors if that is a clue.

Cd -

They're being very cadgy on their website. I don't see this as a production car in any way. It's a design exercise intended to show examples of weight savings that could be integrated into conventional automotive car design. I think they are trying to get their message "into the ether" via the media attention of the X-Prize. Nothing wrong with that.

I bet they are hoping to patent the transfer case :

http://www.edison2.com/picture/gearc...Thumbnail=true
I *could* imagine them selling plans and/or kits to the public.

CarloSW2

I wonder if it is single wheel drive? Should be more efficient and not need a diff.

It looks as if the wheel fairings were designed without reference to the airflow pattern around the main body. It isn't easy to get suspension plus accurate wheel control in the space shown, especially at a reasonable weight. I don't see any gaps or other clearances to allow bounce or even steering, so we may be looking at a crude mock-up. They do refer to swing axles, though, not trailing arms, so perhaps it will have the handling of the old VW bug. I'd also expect stressed body panels in a lightweight, not a tube frame with only a vague attempt at triangulation.

Bob: look at the pics, see how the wheel centerlines are behind the axle tubes. Trailing arms.

I wonder what they think "swing axle" means. I'm content to wait for wait for detailis with the news, if they make some.

I love this car, though its very good aero is more important to its success than its light weight. I'm sure a production version would use cheaper materials, resulting in a heavier car, forcing a larger engine.

One great thing about weight reduction, is that it allows more weight reduction. A smaller, lighter engine can motivate a lighter car, a lighter frame provides the same stiffness as a heavier frame on a heavier car, a smaller gas tank provides the same range, etc.

I would love to see these six gram lug nuts.

Having read about those >1lb brakes (rotors, presumably), I couldn't resist running a calculation. Assume your brakes need to be able to do a panic stop from top speed on a warm day without boiling your brake fluid. Assume that the top speed of the Very Light Car is 75mph, and that its braking system has a thermal mass of 2kg and the same specific heat as cast iron. Thus the mass of the vehicle, its occupants, and its cargo is not more than 315lb.

Uh huh.

Maybe they have aluminium brake rotors with cast iron linings, and a 630lb car?

RobertSmalls -

Thanks for doing this calc. 315 lbs sounds fantastical without using exotic materials like carbon fiber, which they don't want to do. When I was looking at the test mule, I was thinking kit-car tubular chassis. It looks like a dune-buggy.

They claim their brake rotors are 1/5 the weight of a regular car. My car weighs 2400 lbs. From my simplistic POV, 2400 / 5 = 480 lbs. Their mule only has one person driving it, so I will assume only one passenger. The average weight of an American Male is 191 lbs. That's 671 lbs.

Does that look similar to your numbers?

CarloSW2

Okay -- I asked them what their weight goal was (on Facebook) and they answered that it should not weigh more than 1,200 pounds, and they are aiming to be 1,000 pounds or less.

I also noticed on their web page that the engine is a single cylinder. Which makes all the "plumbing" even more mysterious.

And I've now asked how the front suspension is set up.

NeilBlanchard -

1200 lbs without people? Ha ha, that's a Beck Porsche 550 Kit Car from the 1980's. Drop a Porsche engine into it and you have 0-60 in 4.4 seconds. In the mid 1980's.

CarloSW2

"Brakes that normally weigh 10 lbs are less than a pound".

I used 2kg of brake system mass, but maybe that's not fair. If the rotors are thermally coupled to the wheels, and the pads are thermally insulated from the calipers, they might be able to dissipate quite a bit more energy with the brakes than I give them credit for. Or maybe the Very Light Brakes fade when you do a panic stop or go down hills, even if you try engine braking with the Very Small Displacement Engine.

cfg, the standard American male is 191lbs, but it's probably smarter to design for the 90th percentile man. He's closer to 240lbs. Though that didn't stop Honda from selling a car (the Insight) with a 350lb payload capacity. Set two adults in it, and the ride quality suffers noticeably.

What a fascinating concept car, and look at all the speculation we are reduced to. Neil, you should invite the Edison team to join the discussion in this thread. I want to see their wheels and tires, and I want to know if any of their techniques can apply to my Insight.

Okay, I got an answer back on the front suspension:

So, my guess is the trailing arm and spring/shock are at the outer end of the tube/strut, and they are tucked inside the wheel; which is why we cannot see them.

On the weight, remember that the original VW 1L car was 660 pounds, and it had carbon fiber, titanium, magnesium, drilled out bolts. It also had a single cylinder diesel, a 6-speed dual clutch transmission, side view video cameras -- it was unobtanium!

An additional Facebook post from Edison2:

Now, here's a Very Light Vehicle: Driving the Spira 3-wheel prototype

You get enough strength to just get down the road from a box made of common styrofoam insulation with fiberglass tape reinforcing. The Unobtanium I'd like to see developed is foam with dispersed fibers to raise the physical properties. You can start your structural design as a whole-body bike helmet, and then see what else it needs. If it is plenty tough but not rigid enough for modern chassis tuning, a subframe can maintain wheel alignment, as on the Model "T".

From the website autocial.com:

About the engine: "And, while an electric drivetrain packages and is envisioned for the Edison2 (with a name like that…), the X-Prize contestant vehicle will be powered by a 1 cylinder turbocharged 250cc 40-hp Yamaha engine that operates without a throttle. Engine power delivery is regulated by altering the amount of exhaust-gas recirculation in the cylinder."

And the body: "The aerodynamic teardrop shape was honed by a Northrup Grumman expert, and boasts a Cd of around 0.15 (which would rise a bit if developed for production). Note the fixed wing-shaped outriggers supporting the wheels. These don’t move. A patented new suspension packages inside the wheel envelope, blocked from view (and the wind) by the enveloping cycle fenders (they’re mum on its design, but it must be like the Michelin Active Wheel."

The aero engineer was no other than Barnaby Wainfan ( Wainfan Home Page ). Cool!

moorecomp -

Cool. This is vindication of theunchosen's no-throttle thread.

CarloSW2

Ha- cool they're on here!

Then I'll say that I like the pattern 1L set out with the exception of the unobtanium material choices. I think the whole thing could be done with conventional materials yielding a fantastic cost and repairability advantage with not much of a performance disadvantage.

On that note I believe that, from their very nature of being the interfaces on the front line between vehicle mass and outside environment, that wheels should be simple, cheap, repairable, and "expendable" (one of the reasons why I question electric hub motors even though I love the efficiency of the concept). Accidents and whatnot are tough on wheels. I think cheapy regular wheels would be a good thing to have.

A loaded four seater will have most of the mass as occupants and luggage anyway.

Frank -

(I'm obsessed with the Beck 550 kit cars)

Do you think the 40-hp Yamaha engine would work fine in the 550 kit car? I mean, VW Beetles had 40 hp engines back in the day. At 1200-1300 lbs, the 550 could be a "thrifty looker", don't you think? It wouldn't be aero, but it could still get great MPG with a simple-to-repair VW suspension.

CarloSW2