underside air flow

[Hateful]

I've added some foam board and duck tape to the underside of the front bumper to create more of a slope so air will go under the car better.It's covered back as to about 10" behind the radiator still sloping to block air off my oil pan for aerodynamics and to keep cold air and water off the pan as well. Should I try to keep the air flowing under the car and out the back or divert it out the sides? I was considering some homemade side skirts but didn't know if it helps or hurts.

This is an 02 Cavalier BTW/ I'm gonna be made fun of anyway for the red hub caps, so no need to stop now.

[trebuchet03]

I don't think anyone here will make fun of your for your red hubcaps

[Danronian]

Interesting question. I'm going to guess you want to divert it out the back, and not out the sides, but I have no idea why.

The aero issues discussed here are always interesting....

[Hateful]

I was thinking out the back too. I've got the hypermiling techs down pretty well with the scan gauge,so Aero and weight reduction is all I can do now.

[Hateful]

Was in Wal-Mart today and saw this nice roll of aluminum window screen;48"x84". I think I've found the material for the rest of underside enclosure. I built up my homemade duck tape air dam this morning and the car seems to handle better. Drove a little faster than normal testing it and still maintained 35mpg. Later trip to store got SGII tank back up to 38mpg for 100miles so far.

[ZugyNA]

Originally Posted by Hateful

[http://www.gassavers.org/garage_imag...87xm6m324c.jpg
I've added some foam board and duck tape to the underside of the front bumper to create more of a slope so air will go under the car better.It's covered back as to about 10" behind the radiator still sloping to block air off my oil pan for aerodynamics and to keep cold air and water off the pan as well. Should I try to keep the air flowing under the car and out the back or divert it out the sides? I was considering some homemade side skirts but didn't know if it helps or hurts.

This is an 02 Cavalier BTW/ I'm gonna be made fun of anyway for the red hub caps, so no need to stop now.

How about this:

"Vehicle: 2006.5 Jetta TDI DSG
Vehicle Mileage: 1750 Miles
Speed: 72.4 +/- 0.1 mph (GPS)
Temp: 60 degrees F
Wind: Out of the N.N.E.

With VG's Under Front Bumper:

Run 1 North: 46.6 mpg
Run 1 South: 47.2 mpg
Run 2 North: 45.0 mpg
Run 2 South: 49.2 mpg
Average: 47.0 mpg

Difference from Baseline: +2.6 mpg"

[Hateful]

Originally Posted by ZugyNA

How about this:

"Vehicle: 2006.5 Jetta TDI DSG
Vehicle Mileage: 1750 Miles
Speed: 72.4 +/- 0.1 mph (GPS)
Temp: 60 degrees F
Wind: Out of the N.N.E.

With VG's Under Front Bumper:

Run 1 North: 46.6 mpg
Run 1 South: 47.2 mpg
Run 2 North: 45.0 mpg
Run 2 South: 49.2 mpg
Average: 47.0 mpg

Difference from Baseline: +2.6 mpg"

Good numbers; I had to look up "VG" and read a little on it. It seems every graphic I've seen involves a car with a spoiler raised a foot or more off the trunk lid;which I don't have and don't plan to get one( not worried about car leaving the ground at high speeds).
The VG's seem almost too easy of an answer; making some extreme aero work I've seen on the site a big waste of time.I'll read more on the subject once I've done what I've already planned. I tend to watch out for people quoting Machiavelli; though " The Prince" was a good read.

[Hateful]

couple of pictures of air dam and under screen

[Hateful]

I've finished covering the entire underside of my car with window screen. This is touching the exhaust components in several places and has not burned nor melted. I plan now to paint the screen in some places to reduce friction more,leaving other parts near the exhaust unpainted for exhaust cooling. I know I'll have to cut a small hole when I change the oil ( filter is reachable from the top if I remove an electrical component from the fire wall and replace). Just drove 20miles from a cold start and managed 40mpg on 45/55mph zones.

[cfg83]

Hateful -

Originally Posted by Hateful

I've finished covering the entire underside of my car with window screen. This is touching the exhaust components in several places and has not burned nor melted. I plan now to paint the screen in some places to reduce friction more,leaving other parts near the exhaust unpainted for exhaust cooling. I know I'll have to cut a small hole when I change the oil ( filter is reachable from the top if I remove an electrical component from the fire wall and replace). Just drove 20miles from a cold start and managed 40mpg on 45/55mph zones.

EDIT : Nevermind my melting question below, I see from earlier posts that it's aluminum window screen. Won't melt.

Interesting. Is this the "normal" plastic mesh or some kind of metal mesh? The plastic would be easier to install. I wonder why it hasn't melted. If you find it does melt, you could have spacers and/or metal mesh on areas near the cat.

And the paint will fill the little holes in the mesh. Never thought of that ... .

CarloSW2