01-23-2009, 06:10 PM
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#41 (permalink)
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(:
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OK, I'm too lazy to do it myself, but there is an equation for calculating road loads and such. It would take a much larger drag reduction to give a certain fe increase ie. 20% Cd reduce does not equal 20% fe increase- it would be something like, 20% Cd reduction gives 2% fe increase. This whole thing is ridiculous.
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01-24-2009, 09:28 AM
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#42 (permalink)
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Master EcoModder
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Skin friction in itself is less than 20% of total drag in road vehicles.
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01-24-2009, 10:18 AM
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#43 (permalink)
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Philthy
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Quote:
Originally Posted by tasdrouille
Skin friction in itself is less than 20% of total drag in road vehicles.
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Golf ball dimples increase skin friction, so your point is pretty pointless. what they do is create small disturbances in the flow that keep the boundary layer attached to the surface for a longer way around the ball. this reduces the size of the wake behind the ball and therefore reduces the overall pressure drag. this is very important to the aerodynamics of a car, which is why the aerocivic gets such great gas mileage. that said, i don't know if these fast skinz would work. it would depend partly on what the flow over the car is (laminar vs. turbulent) and another part of black magic and make believe.
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01-24-2009, 01:28 PM
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#44 (permalink)
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Master EcoModder
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I had not read their webpage and was under the impression skin friction reduction was their argument.
That being said, in order to achieve 20% reduction in FE you'll need to reduce the Cd by more than 30% as you have to take rolling resistance and driveline/accessory losses into account. That's just not gonna happen.
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01-24-2009, 02:39 PM
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#45 (permalink)
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Master EcoModder
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more info
Quote:
Originally Posted by wyatt
so is it supposed to reduce skin friction? I don't think skin friction if completely eliminated would contribute 20% to MPG. I am with Frank... lost. Need more information to make any assumptions.
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The premise for the product would be that it transitions the boundary-layer from laminar to turbulent,moving the separation point rearward on the vehicle.--------------
Since the boundary-layer is already turbulent on every car on Earth,the product cannot satisfy it's claims.It solves a problem that automobiles don't have.---------------
The 18-20% mpg improvement would require a 40% drag reduction.It's impossible!
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01-24-2009, 02:51 PM
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#46 (permalink)
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Batman Junior
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Quote:
Originally Posted by Frank Lee
OK, I'm too lazy to do it myself, but there is an equation for calculating road loads and such.
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Aerodynamic & rolling resistance, power & MPG calculator - EcoModder.com
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01-24-2009, 02:54 PM
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#47 (permalink)
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Master EcoModder
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"success"
Quote:
Originally Posted by TheScionGuys
Not a sales pitch on my end. We have wrapped two cars and we have seen the "success" in the fuel economy. As I look into it further and research it more I look for opinions/comments as to its true feasibility. I wonder if there is a benefit for only parts of the car (as asked above) to be wrapped to keep costs down vs the return. I have asked for the information from the company as well, but looking to see if anyone has ever done it before. We are experiencing better fuel efficiency just for those wondering and that is why I said that if anyone wanted to come try it out, that I offer it up to them. I don't work for the company, I just believe in the results that we have experienced.
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I believe that you're success is derived from something other than the "wrap." No physical scientific investigation has ever produced results such as are manifested in the claims for the wrap product.---------- And it is still a criminal offense to knowingly false-advertise products which demonstrate no efficacy as to their published advertised claims.Criminal prosecution usually ends in imprisonment,fines,loss of property,and sometimes worse,when victims injured by the deceptive advertising practices take the law into their own hands.---------- Perhaps it would be prudent for the owners of the patent and anyone associated with it,to pay for independent testing and verification before they go down a path they really don't want to go down.
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01-24-2009, 04:52 PM
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#48 (permalink)
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Ultimate Fail
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I didn't click the link at first, because I knew from the start that this thing was a scam.
After reading everyones comments, I got curious and checked out the site.
Sad.
Really, really sad how low some people can go to makea quick buck.
( Did anyone else notice the typos on that site ? )
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01-24-2009, 07:04 PM
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#49 (permalink)
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Quote:
Originally Posted by trikkonceptz
Best bet is to warm up two Scions one of the wrapped and one without and take them out on an extended hwy test drive with equipment, like a scangauge to determine if under very similar conditions there is a 20% difference in FE. Even a crude test like that would at least slow down the ridicule.
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that is exactly what the cars are used for and have been for the past two weeks.
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01-25-2009, 10:05 AM
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#50 (permalink)
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Quote:
Originally Posted by TheScionGuys
that is exactly what the cars are used for and have been for the past two weeks.
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Not to beat a dead horse but Where's the Data?!
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