A "Varna" trike with a small diesel?

[omgwtfbyobbq]

I've ranted about this in the past, but this rant allows a decent apples to apples comparison of what kind of FE a streamlined velomobile/trike with a 10hp diesel should get. Taking the base stats from the varna "Diablo" (source), doubling the reference area (.4), increasing the weight (~300lbs), and increasing the rolling resistance (~.007) yields a glider that should only need ~17N moving at ~55mph.

As for the ICE, since old NA vw's use ~264g/kwh (source), and from what I can gather, the new, small (~4-10hp), DI diesels from Chinamart use about the same amount (source). We can compare the fuel used between both vehicles, approximately. ~520N/17N=30, so if most people get ~50mpg@55mph in a diesel vw, then they should get ~1500mpg@55mph in the barebones diesel trike. Of course this ignores using human power to move down steep enough grades, which would probably push FE over 2000mpg at cruising speeds. Making this thing bearable could be done by adding vents ($cheap), a small battery ($?), one of those heating/cooling seat covers ($120), and a couple digicamcorders (~$45-80) for rear view mirrors. Sure, FE will drop, but at these levels, who cares? Allowing the diesel to be taken in and out easily should let the driver use it with just human power if the area is flat enough and they don't mind cruising at ~25mph. The basic design will be something like this, with a steel body similar to the ariel atom's exoskeleton (for safety), and... believe it or not, a paper mache shell. Which should bring the cost of materials in under a grand... I think it'd be pimpin' for a grand, and you could easily grow enough fuel in your own yard. Any comments? I'm still not quite sure about what kind of transmission would be best for the diesel.

Feel free to move this since it isn't strictly human powered/bicycle either. I just figured the use of a trike and potential pedal power would be fitting here.

[omgwtfbyobbq]

It is way too much! But I'd really like to be able to smoke most cars off the line while having my license plate frame say 1500mpg@65mph, or whatever I get.

What I'll probably do is use a small 2-stroke gasser in the 1-2hp range since they're only ~$150 shipped, less if I find one locally. If I build this according to the specs of that other delta trike, then 1hp should be enough to push me at 55mph on flat ground. The only downside is most two-strokes I've seen have fuel efficiencies of ~600g/kwh, so fuel efficiency would be ~600mpg@55mph. It should allow me to compare these calculations to what I can actually put together.

[The Toecutter]

seriously, the steering was so quick and the power so great, it wasn't even fun- it was scarier than it was fun.

That's just the way I like 'em.

I like the idea of a fared trike the operates using laminar flow.

www.speed101.com/

Those can do 60+ mph on 300W of human power.

Imagine the fun to be had with a 30 kg lithium pack, twin Etek motors, and Zilla 1k controller which would allow ~25,000W of peak power.



But even the modest 10 hp diesel concept is very worthwhile, and much cheaper. It's a matter of fitting the diesel and its ancillary components into such a vehicle. An electric drive would fit more easily. Top speed in either case would be insane.

[omgwtfbyobbq]

Shoot, less than 300W will get you 50 miles in an hour. I was thinking a 6hp continuous, 30hp peak ADC motor with enough li-ion batteries to go 100miles@50mph.... But, how do I deal with the differences in each cell? In any event, I f'ed up, CdA=.4 is roughly twenty times the reference area, but since my rolling resistance was also off, everything works out. With a CdA=.09, something like this

and Crr=.008, it'll need ~800-1000w@50mph.

[The Toecutter]

That's basically a 2 kWh pack for 100 miles range. About $1,400 or so with today's lithium ion prices reflecting a lack of automotive volume.

The management system would be horrendously complicated. But it's nice to ponder the possibilities.

[omgwtfbyobbq]

Yeah, I was thinking NiMH instead. These should fit the bill, and with eight 30 battery 36V strings providing 2.88kwh for ~$1,400, as long as I either match the cells, or don't let the pack discharge past ~1.1-1V, then they should last a decent amount of time. Otoh, I could use smaller strongs with active monitering, but that seems to be pretty expensive. Cooling wouldn't be too hard, rig a flap/fan to a thermistor... And always make sure each string is charged seperately.

Any other ideas? I was thinking about ABM and three cell packs in a series of ten for a thirty cell string with active management because the pack could be switched around if the voltage sags because of a bad cell... Do the Ovonics cells require ABM or could I put three of them in series worry free?

[The Toecutter]

Hell, for that price, I'd rather just salvage a Prius pack(~1 kWh) from a junkyard and try to increase the efficiency of the trike just a little bit more if possible to get the range. Less need for a complicated management syastem then since it's already built into the pack. However, there may be a lot of software issues involved that I'm currently unaware of.

[omgwtfbyobbq]

Worse case, yup, lost of nastiness that would require nabbing the ECU as well and running all sorts of stuff? In anyevent, the worst part is that it cuoldn't come with a reasonable warranty. The yards I usually go to are great, 3 month unlimited mile no questions asked returns for 150% of the price... Which is great for stuff they get in reasonably often, but a Prius pack is one of those once in a blue moon deals, so I might be better off getting a year warranty on a ~$1-2k pack of new batteries? Eh? Gotta get, aka wait for, a job first. If that doesn't pan out I can always babysit teenagers, but I'd rather not.

[red91sit]

I was thinking of doing something like this, more along the lines of a lawnmower engine (3.5 h.p., 2610watt) on a small old-school bicycle, completely unfaired it should be able to get me to school, work, and back in style (he he) with real low fuel consumption. They operate best at low rpm's (efficient!) 2000-3500 rpm's would be my ideal cruising speed. The only thing that scares me is the fact that I'm bypassing any clutch type setup, instead I just push it as fast I possibley can and hop on when the engine starts running, I'll then lug the engine a bit until it gets to a useable speed. The problem i see is braking, i need roughly 18,360 watts of braking energy to stop me and the bike going down the large hill. It's problby a 120 feet down (both to and from school) I"m thinking the stock rubber brakes will either melt, or wear out much too quickly, either way it won't have enough to stop the bike if the motor's stuck on. I also have new shoes which i'd really rather not sacrafice for my safety

[onegammyleg]

Originally Posted by omgwtfbyobbq

Shoot, less than 300W will get you 50 miles in an hour. I was thinking a 6hp continuous,

and Crr=.008, it'll need ~800-1000w@50mph.

I was thinking just last night about this sort of thing.
In most countries its hard to get custom cars passed by the cops , but 3 wheelers come under mortorcycle classifications , and bikes are easier to pass.

Normal motorbikes here have huge insurance fee's (mandatory) but mopots (mopeds and 50cc scooters) have almost no fee's (by comparison).

A slightly more car like design than this powered by a 50cc scooter engine would rock.
I will have to look into this more !!!

[cafn8]

Originally Posted by onegammyleg

A slightly more car like design than this powered by a 50cc scooter engine would rock.

Check this out. A man named Jory Squibb has done that very thing.