Wheel well vents

[aerohead]

Originally Posted by godscountry

One of the bike racers at Battle mountain,Nevada was saying how critical the wheel openings are to the overall drag of the vehicle,don't laugh,these bicycles hit 80 plus mph and they're wheel openings are in the mm.So a car or truck or streamlined motorcycle,I would say it would have a big effect as your speed gets higher.Some of these streamlined motorcycles might pick up a few mpg's just by better sealing the wheel openings and getting rid of some of that dirty air.

'Georgi',designer of the VARNA series of IHPVA racers told us that the 1/4-inch gap between the body and wheels constituted 50% of the bikes drag.

[Shepherd777]

The new Ferrari F60 America, which debuted yesterday, has some extremely large and very beautiful front wheel well vents.

On our new truck, with a 955 cubic inch Cummins ISX diesel engine, we will have some monster engine bay heat extractor vents. Sorry, I can publish any pics of that yet.

[aerohead]

A Viper was apart and I caught this shot

[whatmaycome14]

A quick question for you guys because I still haven't figured it out...

Could you rate the following in order as far as what would be better or worse for drag?

Open wheel well, no modification.
Partial skirt.
Full skirt flush with body, rear vented.
Full skirt flush with body, not vented.
Full skirt flared out, rear vented.
Full skirt flared out, not vented.

I understand air flow a little, but I feel there is still so much for me to learn!

[Frank Lee]

I think if anybody really could answer that, we would have no need for wind tunnels.

[whatmaycome14]

Originally Posted by Frank Lee

I think if anybody really could answer that, we would have no need for wind tunnels.

Thanks for your help Frank.

Really though, is there no theoretical answer?

[2000mc]

Originally Posted by whatmaycome14

Really though, is there no theoretical answer?

Seems like it would theoretically have to be flush with body, and not vented. But I think you have to do a good job of keeping air from entering the wheel well for the theory to nessecarilly work.

[aerohead]

Originally Posted by whatmaycome14

A quick question for you guys because I still haven't figured it out...

Could you rate the following in order as far as what would be better or worse for drag?

Open wheel well, no modification.
Partial skirt.
Full skirt flush with body, rear vented.
Full skirt flush with body, not vented.
Full skirt flared out, rear vented.
Full skirt flared out, not vented.

I understand air flow a little, but I feel there is still so much for me to learn!

My opinion would be to go with the flush,non-aspirated, full skirt.They show up on the lowest drag vehicles.

[aerohead]

Originally Posted by whatmaycome14

Thanks for your help Frank.

Really though, is there no theoretical answer?

The lowest drag forms are bodies based upon streamline bodies or wing sections.Empirical testing revealed that fully-enclosed wheels,with closed,contour-fitting skirts provide the lowest drag.
With wheel fairing the drag goes even lower,as in Hucho's words "the wheels are integrated into the body."
Delft University is currently the world leader in low drag,unless you can find Ford's 'UFO' of the late 1980s-early 90s.

[Frank Lee]

Sure, but if the question includes, "If I slap skirts- even flush non-vented ones- on my car, is it more aero?" can we definitively say yes it is?