[mcrews]

Originally Posted by botsapper

The BMW air curtain is a very subtle corner canard as compared to very extravagant front corner versions from the Japanese racing aftermarket. These external examples are corner box canard/splitters. Note the horizontal winglets are angled flat, collecting front air pressure flow and narrowing it down just before the well opening, probably with similar hopeful results.
http://www.gtrblog.com/wp-content/up...02-540x405.jpg
Other concept cars with these devices.
http://theblogaboutcars.com/wp-conte...citroen-GT.jpg

this thread has seemed to drift (no pun intended) on and off the specific topic of the 'curtain' as a shield.

I started back at the beginning and reread the posts.
While botsappers pictures were cool, I realized that the point was off base.

THE idea of the canard is (when placed at the 40-60degree angle) is to increase the downward air presure on the front corner, forcing the front tire down harder . Catching the air that would whip around higher than the splitter.
The splitter, of course is also increasing the downward presure on the front end.

also, as the first pictures show of the air flow (& the front slots), the air being captured for the 'curtain' is ONLY the air that is caught in the thin slot that then slides along the INSIDE wall of the fender (flat) to then exit uot the slot toward the tire.

I am sure that there is a relationship with how far uot/in the side of the tire is at in relation to the edge of the fender. I would imasgine that IF the tire was 10mm farther uot, the entire concept of 'curtaining' would fall apart.

As this thread has develped, my thoughts are this.
1. There was a point where the BMW automobile looked VERY dull from the front.
2. obvioulsy driven by windtunnel design.
3. WT/airflow was also leading to flat wheel designs or flat wheel covers.
4. I think that either by accident (think 3M sticky pad glue) or by thinking outside the box, someone discovered this concept 'the air curtain'
5. It allowed them to have a very aggrssive front look, with slots and opening, allowed them to have agressive looking wheel designs that weren't 'areo/eco flat'.
6. Gave some very minimal gain in cd while giving the larger advantages listed above.

reminds me a lillte bit of engine design thru the early 80's in the US. all the bolt-on epa stuff looked like crap hanging all over the engine, with no rhyme or reason as to why it was there.
In 1984, the totally redesigned Chevy Corvette had re-thought every part on the engine and created an engine that actually was pleasant to look at.