Air Dam and Front Undertray - Page 4 - Fuelly Forums

Click here to see important news regarding the aCar App

Reply
 
Thread Tools Display Modes
 
Old 04-15-2007, 05:34 AM   #31
Registered Member
 
Join Date: Dec 2006
Posts: 84
Country: United States
Quote:
Originally Posted by red91sit View Post
Not neccesarily, you go too low, and You increase frontal area causing more aerodynamic drag.
Not according to the March 2007 issue of Hot Rod Magazine.
Page 115 article "wind camp" under section, "tech theory" Sub article, "top 5 easy areo mods that almost always works" states this;

"You can usually get 90 percent there just by adding a dam striaght down from the front bumper......we have that big barn door on the front of the car, but keeping air out from under the car both reduces drag and neutralizes lift for solid areo gains....20 counts less drag and 50 less lift. the taller the car sits, the more important the air dam is."

It further states that the benfits of a large air dam outweights the higher frontal area.

Anyhow, Great info on you dam article!!!!!

Looking to do mine soon as well.
__________________

__________________
brelandt is offline   Reply With Quote
Old 04-15-2007, 08:42 AM   #32
Registered Member
 
zpiloto's Avatar
 
Join Date: Mar 2006
Posts: 1,225
Country: United States
I agree with red91sit on this. I found it to be true with the mazda 626 anyway. YMMV.
__________________

zpiloto is offline   Reply With Quote
Old 04-15-2007, 09:22 AM   #33
Registered Member
 
Join Date: Dec 2006
Posts: 84
Country: United States
How tall are we talking about?

If you watch NASCAR which I don't or have ever seen a NASCAR you will see how freaking hugh their dams are as well to how low to the ground they are. The car has a much greater frontal area than any stock version of said car but is much more areo efficent.

Now if you are talking about adding a bumper to ground dam on lets say a 1985 K-Blazer with a 6 inch lift than yes there will be a neg. effect.
__________________
brelandt is offline   Reply With Quote
Old 04-15-2007, 11:13 AM   #34
Registered Member
 
Join Date: Mar 2007
Posts: 1,138
Country: United States
Quote:
Originally Posted by brucepick View Post
Bill in Houston,
I think you did a great job.

I drive an "89 Volvo with OEM air dam that was standard on those cars but I hope to add an extension downward based on what you showed.
Thanks!

I hope your extension works out well for you. Extending the OEM air dam should be a relatively simple task since your attachment points are all figured out.

Something that I read, and that I believe, is that behind the air dam, you need a smooth surface to get as much drag reduction as possible, so I built the undertray. The undertray also helps take a lot of flex out of the dam too.

Anyway, good luck and keep us posted.
__________________
Bill in Houston is offline   Reply With Quote
Old 04-15-2007, 03:03 PM   #35
Registered Member
 
zpiloto's Avatar
 
Join Date: Mar 2006
Posts: 1,225
Country: United States
Quote:
Originally Posted by brelandt View Post
How tall are we talking about?

Quote:
I brought it down to 4 inches off the ground.
Now if you are talking about adding a bumper to ground dam on lets say a 1985 K-Blazer with a 6 inch lift than yes there will be a neg. effect.
According to Hot Rod mag you quoted it would especially be need for the example above.

"You can usually get 90 percent there just by adding a dam striaght down from the front bumper......we have that big barn door on the front of the car, but keeping air out from under the car both reduces drag and neutralizes lift for solid areo gains....20 counts less drag and 50 less lift. the taller the car sits, the more important the air dam is."

Don't know about NASCAR but it didn't work for me but the belly pan sure did. YMMV
zpiloto is offline   Reply With Quote
Old 04-16-2007, 07:29 AM   #36
Registered Member
 
brucepick's Avatar
 
Join Date: Feb 2007
Posts: 722
Country: United States
Location: Connecticut
Quote:
Originally Posted by Bill in Houston View Post
... Something that I read, and that I believe, is that behind the air dam, you need a smooth surface to get as much drag reduction as possible, so I built the undertray. The undertray also helps take a lot of flex out of the dam too...
Thanks Bill,

Hmm. The car has a short OEM belly pan but it starts just under the radiator/ac condenser. In other words, does not continue directly off the bottom rear of the air dam. Pan extends only about 18 inches to front of block. Pretty good considering it's from '89 though.

I could fairly easily put in a panel going across rear bottom of air dam to the front of belly pan. Should give some improvement, right? (When dam's lower extension is built I'd attach to rear bottom of that.)

Is that you have in mind? Of course a full lower pan would be best - but that's more involved; still considering that for when warmer weather gets here.
__________________
Currently getting +/- 50 mpg in fall weather. EPA is 31/39 so not too shabby. WAI, fuel cutoff switch, full belly pan, smooth wheel covers.

Now driving '97 Civic HX; tires ~ 50 psi. '89 Volvo 240 = semi-retired.
brucepick is offline   Reply With Quote
Old 04-16-2007, 05:55 PM   #37
Registered Member
 
Join Date: Mar 2007
Posts: 1,138
Country: United States
Quote:
Originally Posted by brucepick View Post
I could fairly easily put in a panel going across rear bottom of air dam to the front of belly pan. Should give some improvement, right? (When dam's lower extension is built I'd attach to rear bottom of that.)
Yep, that is what I was talking about. Sounds good to me. A small improvement, maybe, but an inprovement nonetheless.
__________________
Bill in Houston is offline   Reply With Quote
Old 04-17-2007, 07:18 AM   #38
Registered Member
 
brucepick's Avatar
 
Join Date: Feb 2007
Posts: 722
Country: United States
Location: Connecticut
[Bill] - Yup.
They're all small improvements and they add up.

Heh-heh, back in the '70's the joke was that this guy said he bought every fuel-economy-improvement doodad and magic fluid he could find. Every one of them claimed to reduce gas consumption by 5 or 10 percent. Eventually he noticed that the tank got more and more full as he drove down the highway....
__________________
Currently getting +/- 50 mpg in fall weather. EPA is 31/39 so not too shabby. WAI, fuel cutoff switch, full belly pan, smooth wheel covers.

Now driving '97 Civic HX; tires ~ 50 psi. '89 Volvo 240 = semi-retired.
brucepick is offline   Reply With Quote
Old 04-17-2007, 08:32 AM   #39
Registered Member
 
Join Date: Mar 2007
Posts: 1,138
Country: United States
:-)
__________________
Bill in Houston is offline   Reply With Quote
Old 04-17-2007, 04:54 PM   #40
Registered Member
 
Join Date: Dec 2006
Posts: 84
Country: United States
Quote:
Originally Posted by zpiloto View Post
According to Hot Rod mag you quoted it would especially be need for the example above.

"You can usually get 90 percent there just by adding a dam striaght down from the front bumper......we have that big barn door on the front of the car, but keeping air out from under the car both reduces drag and neutralizes lift for solid areo gains....20 counts less drag and 50 less lift. the taller the car sits, the more important the air dam is."

Don't know about NASCAR but it didn't work for me but the belly pan sure did. YMMV
Belly pan would be the best way of going about it. Unfortunately for me and my pug nosed Sidekick with really low underhangs it's impossible.

The only way for me to keep the air from getting all turbulant and messy is to just block it off from getting there to begin with.

However, I have not done this yet and I may have to lower the truck first. When I do build mine I will make it just low enough to cover all of the hanging parts without lowering the truck.

If this doesn't work, than I will build the dam lower to the ground. Then if need be I will lower the whole truck, but as a last resort.

Also the dam works better if placed even with the front edge of the bumper and not behind it like almost all air dams are.

Anyhow, Good job Bill in Houston!!!!!
__________________

__________________
brelandt 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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Strange fuel-up calculations with odometer. Honva Fuelly Web Support and Community News 3 04-27-2012 04:30 AM
Why doesnt my car show up under 'browse vehicles'? frederic73 Fuelly Web Support and Community News 4 06-17-2011 03:00 AM
Gas Log? GasSavers_Kraig General Discussion (Off-Topic) 3 08-16-2006 01:21 AM
Looking for Insight wheel numbers GasSavers_Ryland General Maintenance and Repair 3 07-08-2006 10:02 PM
Car wrecked. Compaq888 General Discussion (Off-Topic) 80 06-14-2006 11:23 PM

» Fuelly iOS Apps
» Fuelly Android Apps
Powered by vBadvanced CMPS v3.2.3


All times are GMT -8. The time now is 12:20 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.