'97 Passat TDI Build

[freebeard]

What is 'The Theory' behind these vent things and what are they called??

Your search term is 'air curtain'.

EcoModder.com
Air Curtain - Fuel Economy, Hypermiling, EcoModding News and Forum ...
"The new Air Curtain is the latest innovation BMW aerodynamics. First introduced in the BMW 1 Series M Coupe, Air Curtain now would be a standard feature on the 128i Convertible. Air curtain increase airflow around the front wheel arches with the benefits of turbulence are significantly reduced."

[Logic]

Originally Posted by freebeard

Your search term is 'air curtain'.

Ah! Thx freebeerd. I'm getting 'the picture' now. Kinda like a 'blown wing'!
(My brain being lazy! )

Caddylackn:
If you want to get into the (very) fine details of ducts you want to round that duct's leading edge, with sandpaper, with more rounding of the inner edge than the outer.
Sharp 90 degree edges are anathema to getting air through a duct! (Or to follow the outer skin)
Half ellipse (3 to 1 ratio) in the front leading edge; sharp trailing edge.
As doing so is pretty quick and easy; why not...

I'd also consider polishing the inner surface as skin friction plays a very big part in long ducts.
The science I found said that a finish using anything below 500 grit sandpaper was very bad.
You also don't want any screws etc sticking into the duct

Then, as the top of the wheel and tire moves forward at 2X the car's speed (Squared for aero) one would think that directing the exit flow downward some is a good idea..?
(Bottom of the wheel is doing 0 mph forward..!)
Everyone??
The thread on this's pics do seem to point to these pointing air to the lower part of the wheel, rather than the top as Caddylackn has it..?

[freebeard]

If you want to get into the (very) fine details of ducts ... Sharp 90 degree edges are anathema

Vena Contracta

(A new handle -- 'freebeer[e]d)

[Caddylackn]

I painted my car last summer after finishing the bodywork and modifications.
Here is an attempt to document it with photos

Photo #1 - filling all the roof antenna holes. I think there were five of them.

[Caddylackn]

#2 Smoothing out the metal work. Little ripples from heat needed more coverage

#3 is Roof paint after urethane primer. Spoiler primered

[Caddylackn]

Time to fix all the door dings and parking lot dents

[Caddylackn]

[IMG][/IMG]

[IMG][/IMG]

To be sanded with 240, then glazing putty touch up, then 400 grit

[freebeard]

I painted my car last summer after finishing the bodywork and modifications.
Here is an attempt to document it with photos

Still in primer, or was this a year ago?

[Caddylackn]

Epoxy primer sealer in black. It dried satin. I needed black as the base coat for a color changing pearl I was using. Final color is Dark/Light green shifting to Dark Blue. I used Eye Candy - Sushi Roll.

[IMG][/IMG]

[Caddylackn]

[IMG][/IMG]


[IMG][/IMG]