Aerodynamics of Lexus LS 430 wheel spoilers

[silverfrost1]

There has been some discussion here on aerodynamics, Cd, downforce, so here goes:

On the Lexus LS 430 there are wheel spoilers, (air dams?) located on the undercarriage in front of each wheel well. They are made of synthetic rubber, are about 200mm wide and extend about 30mm down from the car body. I assume the Lexus engineers put such things on cars for a reason. What is the design intent? More downforce? Less drag?

BTW, these Lexus LS 430s do not have dimpled panels on the undercarriage, they have corrugated plastic panels, each corrugation about one inch wide.

 

[GregLocock]

Yes, also they might affect yaw stability.

Plus they keep mud splashes off the rockers...

Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[silverfrost1]

Upon further reflection, those little air dams might be for a venturi effect, because they only extend half way into the tread area, and have a slight L-shape. The air flow is forced around the tire to the brake side, breaking up the vortex of the spinning wheel.

 

[NickE]

Yep thats what they do, or at least appear to do. My mom's (and why is it that every time I hear of a Prius its someones mom's car) Prius has them too.

Greg -- Leading edge of the wheel well.

(although they would keep some mud off the front bumper and the rear doors)

 

[Peter7307]

Yep thats what they do, or at least appear to do. My mom's (and why is it that every time I hear of a Prius its someones mom's car) Prius has them too.

Actually it is to avoid admitting THEY (big, rugged, macho, chew nails and spit rust, 4 x 4 types ) actually drive them as well !

Incidentally, several other car makers use similar devices ahead of the front wheels. Mostly they rae dark coloured flexible materials and are often difficult to detect at a casual glance.

Cheers , Pete.