02-27-2008, 05:57 PM
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#11 (permalink)
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MechE
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Quote:
Originally Posted by H4MM3R
True, there is something to gained in aero even at 25mph. However weight and rolling resistance have more of a drag then aero at speeds below 40mph. Above 40mph aero is the greatest resistance the car has to work against.
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Can you quantify that for us? (I'm really curious where this 40mph number came from - you're not the first to use 40 or something really close).
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02-27-2008, 06:01 PM
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#12 (permalink)
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EcoModding Apprentice
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That is something I remembered from reading about aero and cars over the years. I will see if I can find a link or something that will quantify it.
trebuchet03~Good idea.
Last edited by H4MM3R; 02-27-2008 at 06:01 PM..
Reason: dropped a word
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02-27-2008, 06:03 PM
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#13 (permalink)
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Master EcoModder
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our university just got one, it was dark when I was looking at the window sticker, but I stoped in and talked to the DMV guy, he said our state NEV law allows for 35mph speed limit and they have to at a minum be able to go 25mph in a quarter mile.
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02-27-2008, 06:11 PM
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#14 (permalink)
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Pokémoderator
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basjoos -
Quote:
Originally Posted by basjoos
Its aerodynamics don't look all that great, with a level roof line, open wheel wells, open wheel spokes, various stying bumps and grooves, and something hanging down underneath it (no underbody paneling?). I wonder what kind of speed and range improvement it would get with a decent aero treatment.
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I think the 25 MPH speed limit is a safety issue. I am sure that they are artificially set to 25 MPH max. It's a safe bet that these electrics don't pass "normal" crash tests. At 25 MPH, does aerodynamics matter?
CarloSW2
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02-27-2008, 06:14 PM
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#15 (permalink)
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MechE
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Quote:
Originally Posted by H4MM3R
That is something I remembered from reading about aero and cars over the years. I will see if I can find a link or something that will quantify it.
trebuchet03~Good idea.
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Here's the numbers based off experimental data collected for a Metro.
The cD, cRR, Mass and A values in here
At 40mph (17.88 m/s) @ 25C ambient temp
RR = 23.37 pounds (1000kg*.0106 -> converted from N to
AeroD = 36.214 pounds
At 25mph (11.7m//s) @ 25C using the 1350lb curb weight (1200lb for the NEV + 150 for 1 occupant) - I'm going to assume it has identical cRR and cDA to the Metro (I don't have the data - so this is just like we've reduced the weight of the Metro to that of the NEV)
RR= 14.31 pounds
Aero = 14.13 pounds
Ha - that's funny that it's .13 and .31 So it's pretty damn even. But again, an all or nothing attitude will result in neither As they're already using lightweight components for the frame and body - it will likely be more expensive to start using more exotic materials.... But, my point is - 40mph is rather arbitrary...
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Cars have not created a new problem. They merely made more urgent the necessity to solve existing ones.
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02-27-2008, 07:21 PM
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#16 (permalink)
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Batman Junior
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Quote:
Originally Posted by tjts1
Very cool. I saw one in Barcelona back in the summer of 2006. I didn't even realize it was electric at the time.
I think its made in Canada.
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That one's probably not electric. I think I see a muffler by the left rear wheel...
The cars are made in France as ICE driven vehicles in the "quadricycle" class. ZENN buys engine & transmission-less "gliders" and ships them to Quebec where they assemble the electric drivetrain, battery packs & electronics into them:
Quote:
Originally Posted by Christopher Jordan
Zenn got a "cease operations" order- last week I think. Canada won't allow them for some reason.
.... It is such a shame that these might disappear.
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They can be sold here, but only one province currently lets people drive them on public roads. Transport Canada is trying to discourage the NEV class in Canada for some reason. They'll continue to be legal in the US and elsewhere, and in some states, they're able to go 35 mph.
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02-27-2008, 07:39 PM
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#17 (permalink)
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Banned
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Ahhh that explains it. The body shell seems remarkably strong in a frontal impact. Too bad they didn't see fit to include a collapsible steering column. I don't think i saw an airbag on the electric Zenn.
For the same money, I think I would go for a Smart instead.
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02-27-2008, 08:35 PM
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#18 (permalink)
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EcoModding Apprentice
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Sure dollar for dollar the smart is a better car.
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02-28-2008, 12:17 AM
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#19 (permalink)
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EV test pilot
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Cool little car. Not perfect but definately a step in the right direction.
A dealer in Wisconsin started carrying them not too long ago. Couldn't legally drive them out of the lot because the city didn't allow NEVs. They got that changed now.
Would be great to have them go faster, but it is a speed/safety/regulation issue.
My electric motorcycle can legally go any speed I can get it up to. Also, cars converted to electric don't have to worry about NEV laws because they already have the crash testing and airbags.
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02-28-2008, 02:43 AM
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#20 (permalink)
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Master EcoModder
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Quote:
Originally Posted by MetroMPG
T
They can be sold here, but only one province currently lets people drive them on public roads. Transport Canada is trying to discourage the NEV class in Canada for some reason. They'll continue to be legal in the US and elsewhere, and in some states, they're able to go 35 mph.
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Great news! The Zenn competitor- Xebra- is also being sold in our town; but it will do 35 mph. The salesmen for the Zenn were saying lighter lithium batteries and higher speed limits were being planned.
A plain Zenn with no options was in the $12,800. range. That is the next hurdle- for that price, an electric velomobile would be a bargain!
countersTrike
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