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Old 02-13-2010, 05:43 AM   #34 (permalink)
lunarhighway
Master EcoModder
 
Join Date: Feb 2008
Location: belgium
Posts: 663

vectra a - '95 Opel Vectra GLS
90 day: 37.51 mpg (US)
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@ thatguitarguy

Quote:
Originally Posted by lunarhighway View Post
...aerodynamically my version didn't work well, so i ended up taking it off but technically the system worked well, it didn't reveive more than a few scratches on the bottom
A couple of questions:

Do you have any ideas about why it didn't work aerodynamically?

And, what is your belly pan made of? It's hard to tell in the photo, but it looks kinda like OSB?


sorry to be so late to respond.

the original undertray in that picture was made from aluminium, and has since been replaced with coroplast.

i'm not sure why the dams didn't work but i think it's because they didn't cover enough tire with but to much tire height, as well as to much of the wheel well was covered.

it's not like they killed milage but i found no indication either in preceived driving behaviour as in actual FE

i must say however i only use tank to tank results so evaluatings mods like this is not very accurate to say the least.

i think the main thing with these fairings is that they cover the full width of the tire.

most older cars have bumpers that curve in and leave the lower outer portion of the tire exposed.

i'm curently running wheel dams as seen on many todays cars, with dimentions derived from measurements (1/6th tire height ground clearence below the dam) the dam coveres the inner half of the tire as well as part of the wheel well, but in front of the whell they curve backwards.

also seen from the sides the dams curve backwards slightly,

these dams "appear" to help as the car "feels" better to drive and will coast further. the weather is such however (snow and freezing) that i can't vouch for their effectivenes
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aer·o·dy·nam·ics: the science of passing gass

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