To all the aero geniuses/creative inventors.... - Page 2 - Fuelly Forums

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

Go Back   Fuelly Forums > Fuel Talk > Aerodynamics
Search Today's Posts Mark Forums Read Click Here to Login
Reply
 
Thread Tools Display Modes
 
Old 07-02-2007, 05:15 AM   #11
Registered Member
 
Join Date: May 2007
Posts: 101
Country: United States
Send a message via AIM to Raccoonjoe Send a message via MSN to Raccoonjoe Send a message via Yahoo to Raccoonjoe
OK...time to revive this thread.

After a Friday evening fueled mainly by Cap't 'n' Cokes, Julie is now proudly sporting a Coroplast belly pan. It goes from the air dam, angled down to the front axle, terminating just barely behind the axle
*working on pics, will post in garage soon*

Here's my problem. We went up to the lake this weekend, roughly 150 miles round trip....95% highway. It was a little faster than I usually drive on the way up (roughly 70), about normal speed on the way back (55). However, I did a rough calculation of my MPG, and came up with 18.5. Why would this be down from my normal 19.5-20.5??

Ideas would be great....I'm going to leave it in place for this week, and run some normal miles commuting. We'll see if it makes a difference there.

*edit* Forgot to mention something else. I noticed that engine bay temps seem to have risen a great deal, while coolant temps seem to have dropped. Anyone else noticed anything similar??
__________________

__________________
Raccoonjoe is offline   Reply With Quote
Old 07-02-2007, 06:01 AM   #12
Registered Member
 
Join Date: Mar 2007
Posts: 1,138
Country: United States
Speed kills (MPG)

My front undertray, in its initial configuration, created pretty noticeable downforce, and didn't help mileage a lot, or may have actually decreased highway mpg. I lowered the rear edge of it and now it makes less downforce and my mileage seems to have improved.

It will be good to see your photos.
__________________

__________________
Bill in Houston is offline   Reply With Quote
Old 07-02-2007, 06:50 AM   #13
Registered Member
 
Join Date: May 2007
Posts: 101
Country: United States
Send a message via AIM to Raccoonjoe Send a message via MSN to Raccoonjoe Send a message via Yahoo to Raccoonjoe
OK, photos are in the garage now. Basically, you get to see a before shot, then 2 afters.....also one looking in from the drivers front wheel-well.

I wouldn't think I'm getting downforce...actually expecting some lift out of the undertray. The front of the tray is about 8" from the ground, while the back is roughly 6" (maybe a little higher on the right side....)
__________________
Raccoonjoe is offline   Reply With Quote
Old 07-02-2007, 06:58 AM   #14
Registered Member
 
Join Date: Mar 2007
Posts: 1,138
Country: United States
Ya, it looks like it would make a little lift. I'm gonna blame your mileage drop on the speed, and see how the next tank goes. Hmm...
__________________
Bill in Houston is offline   Reply With Quote
Old 07-08-2007, 11:53 PM   #15
Registered Member
 
sonyhome's Avatar
 
Join Date: Jul 2007
Posts: 150
Country: United States
If you make a curve that goes towards the ground it makes lift?
Doesn't it increase the distance the air travels to the back of the car, making the wind faster and therefore would create down force (aka lift that goes towards the ground)?

Aerodynamic 101
__________________

sonyhome is offline   Reply With Quote
Old 07-09-2007, 05:25 AM   #16
Registered Member
 
brucepick's Avatar
 
Join Date: Feb 2007
Posts: 722
Country: United States
Location: Connecticut
Is the leading edge of coroplast snug against the existing material so it doesn't catch air?

And consider extending existing air dam closer to the ground. If belly sheet slopes down towards the rear then you're better off adding a piece to the air dam to make it reach closer to ground, and having a belly pan that's more level. Because the air dam extension will push air off to the sides away from the car. Down-sloping belly sheet grabs that air and attempts to compress it which causes lift and turbulence.

Just my two cents worth.
__________________

__________________
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
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
Trying to add a car bw61374 Fuelly Web Support and Community News 1 08-17-2013 08:14 AM
Fuelly Mobile Location Data xbadcrcx Fuelly Web Support and Community News 4 06-29-2011 06:00 AM
elg's Project zpiloto General Fuel Topics 2 03-03-2007 07:47 PM
I'm going nuts! buying tires soon lovemysan General Fuel Topics 11 12-23-2006 09:13 AM
Search feature added Matt Timion Fuelly Web Support and Community News 1 09-26-2005 03:02 PM

Powered by vBadvanced CMPS v3.2.3


All times are GMT -8. The time now is 01:01 PM.


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