air dam and vortec generators - Page 5 - Fuelly Forums

Android Users - Coming Soon! - Migrating from aCar 4.8 to 5.0

Reply
 
Thread Tools Display Modes
 
Old 06-08-2008, 08:24 AM   #41
Registered Member
 
civic_matic_00's Avatar
 
Join Date: May 2008
Posts: 101
Country: United States
Quote:
Originally Posted by SL8Brick View Post
Keep us posted....I'd be most interested in your results.

BTW, is your Civic a sedan? Its difficult to tell from your garage photos.
yup, the civic is a sedan, LX.
__________________

__________________
civic_matic_00 is offline   Reply With Quote
Old 06-08-2008, 08:28 AM   #42
Registered Member
 
civic_matic_00's Avatar
 
Join Date: May 2008
Posts: 101
Country: United States
Quote:
Originally Posted by COMP View Post
i like the plastic spoons
LOL! I thought about just using the spoons but the wife would probably disown the civic if I do!
__________________

__________________
civic_matic_00 is offline   Reply With Quote
Old 06-08-2008, 03:08 PM   #43
Registered Member
 
SL8Brick's Avatar
 
Join Date: Jun 2007
Posts: 180
Country: United States
Quote:
Originally Posted by Hateful View Post


I made these from wood. I think the shallow holes will provide a little extra turbulence.
Man, those things are HUGE.
__________________
1993 Volvo 240 Wagon - 323k miles (awaiting recommissioning)
1999 Audi A6 Avant Quattro - 149k miles(the NEW daily driver)
SL8Brick is offline   Reply With Quote
Old 06-08-2008, 03:41 PM   #44
Registered Member
 
Join Date: Jun 2008
Posts: 123
Country: United States
Quote:
Originally Posted by SL8Brick View Post
Man, those things are HUGE.
i agree,,they need to be that tall ???
COMP is offline   Reply With Quote
Old 06-08-2008, 06:01 PM   #45
Registered Member
 
Hateful's Avatar
 
Join Date: Nov 2007
Posts: 321
Country: United States
Send a message via AIM to Hateful
Yes, they are bigger than what I've seen in pictures and links here; other than those air-tab things. I've only driven with all of them on today. I had two pieces of the flagging tape on the back glass and drove up to 48mph. The tape did not move any at all, until I reach 45mph. Then the drivers side tape would flutter a little,but still stayed straight ( no twisting to the right or left nor leaving the surface of the glass. It seems to pick up speed more coasting down hill. I live on a gravel road; the dust behind my car coming home did not rise above the height of my car. I've watched other cars at the same speed and the dust would go 15 to 20 feet high.
It seems to be working. If they are too big, I don't know. Look Funny? I'm sure they do,but that line has long since been crossed.
Hateful is offline   Reply With Quote
Old 06-08-2008, 07:09 PM   #46
Registered Member
 
SL8Brick's Avatar
 
Join Date: Jun 2007
Posts: 180
Country: United States
Hateful, Here's an excerpt from the Mitsu PDF relating to VG size that's relevant here:

Quote:
In connection with the size, the thickness of the boundary layer is measured based on the assumption that the optimum height of the VG would be nearly equal to the boundary layer thickness. Fig. 4 shows the velocity profile on the sedan’s roof. From this figure, the boundary layer thickness at the roof end immediately in front of the separation point is about 30 mm. Consequently, the optimum height for the VG is estimated to be up to approximately 30 mm.
Your delta fins might be creating vortices, but they're also extending beyond the boundary layer and most likely creating unwanted drag.
__________________
1993 Volvo 240 Wagon - 323k miles (awaiting recommissioning)
1999 Audi A6 Avant Quattro - 149k miles(the NEW daily driver)
SL8Brick is offline   Reply With Quote
Old 06-08-2008, 07:29 PM   #47
Registered Member
 
Hateful's Avatar
 
Join Date: Nov 2007
Posts: 321
Country: United States
Send a message via AIM to Hateful
Quote:
Originally Posted by SL8Brick View Post
Hateful, Here's an excerpt from the Mitsu PDF relating to VG size that's relevant here:



Your delta fins might be creating vortices, but they're also extending beyond the boundary layer and most likely creating unwanted drag.
I considered drag. There are grooves and indentions that I carved ( with a dremel tool) into them,tapering the back to avoid drag.
Hateful is offline   Reply With Quote
Old 06-08-2008, 07:50 PM   #48
Registered Member
 
SL8Brick's Avatar
 
Join Date: Jun 2007
Posts: 180
Country: United States
OK, although I'd prefer a smooth surface, there's nothing wrong with the grooves. And tapering the fins into a convex shape is good. It's the overall height of each fin that we're questioning.

Maybe the angle of your photo is deceiving...exactly how tall is the trailing edge of each delta fin? Just curious.

__________________
1993 Volvo 240 Wagon - 323k miles (awaiting recommissioning)
1999 Audi A6 Avant Quattro - 149k miles(the NEW daily driver)
SL8Brick is offline   Reply With Quote
Old 06-08-2008, 08:04 PM   #49
Registered Member
 
Hateful's Avatar
 
Join Date: Nov 2007
Posts: 321
Country: United States
Send a message via AIM to Hateful
from the far end back they are 2 1/4 , 2 3/4 , 3 , 3 and the next three at 2 1/2 inches.
Hateful is offline   Reply With Quote
Old 06-08-2008, 08:32 PM   #50
Registered Member
 
SL8Brick's Avatar
 
Join Date: Jun 2007
Posts: 180
Country: United States
Alright, I'd like to propose a possible scenario on what you've done. At their current height, your VGs are probably inducing effective vortices at lower speeds(guessing up to 45mph). But at higher speeds when the boundary layer is fully formed, they're creating vortices and a measurable amount of drag. At some point(highway speed) their height will become a disadvantage since the drag they create will nullify the drag alleviated behind the vehicle.

Its just a guess...does this make any sense?
__________________

__________________
1993 Volvo 240 Wagon - 323k miles (awaiting recommissioning)
1999 Audi A6 Avant Quattro - 149k miles(the NEW daily driver)
SL8Brick is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Powered by vBadvanced CMPS v3.2.3


All times are GMT -8. The time now is 05:41 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.