I noticed these two little flaps under front bumper and just in front of the wheels. Would anyone care to guess what purpose the serve?

Side view.

I believe it is aerodynamically more efficient for the oncoming air to hit those things, rather than the spinning tire head on.

it might be, at speeds +70mph, and the effect would be not so big... (there are other things which would be addressed first if they were that worried about aero)
hmmmmmm... i really can't wager a guess as to what those'd be for...

They are mud flaps for when you drive in reverse :D

those flaps r on my bmw also

Yeah, my guess would be that they're to divert airflow down towards the ground, rather than having it hit to tyres head on. I don't know what sort of effect that these would have though.:confused:

Originally posted by Kansei_Jim
I believe it is aerodynamically more efficient for the oncoming air to hit those things, rather than the spinning tire head on. Yep. It has been found that the air on the bottom of the tire (not because it's spinning) causes some lift at speed. The flaps have been installed to divert air and minimize that lift. They are commonly called "speed flaps".

---jps

In some shots you can see flaps in front of the rear tires also.

You guys are probably right. The back also has one in front of each wheel. I noticed it on the BMW too. But it doesn't seems to be common on cars.

hmmmm...
i'd still rather see a full blown aero kit, however minimal, rather than a half-hearted attempt...

of course, that is a cheap, easy way to reduce a good amount of drag... but that won't cut lift, and there ARE more problematic areas (ie: ass of the car)

wheel spats.

Honda S2000 has these standard also, except that that they are more noticable.

Originally posted by wakeech
hmmmm...
i'd still rather see a full blown aero kit, however minimal, rather than a half-hearted attempt...

of course, that is a cheap, easy way to reduce a good amount of drag... but that won't cut lift, and there ARE more problematic areas (ie: ass of the car) It won't cut lift? I guess that all of those car makers are just doing that for "rice effect" then, huh?

Although it might not be as effective as a full body kit, it adds some benefits without taking away any of the undercar clearance.

---jps

:p tell me how pushing air down (which results in an upward "equal and opposite reaction") reduces lift smarty pants... also, it reduces the negative lift effect the front of the wheel arch may generate...

but it certainly will cut some drag, diverting airflow away from the wheels :p

Originally posted by wakeech
:p tell me how pushing air down (which results in an upward "equal and opposite reaction") reduces lift smarty pants... also, it reduces the negative lift effect the front of the wheel arch may generate...

but it certainly will cut some drag, diverting airflow away from the wheels :p

I can't vouch for how much lift is really being produced and whether it really affects handling. For what it's worth though, if the flaps do produce lift it would be on the body of the car and that might be technically better than having lift under the wheels.

:D it wouldn't be producing much appreciable lift, just as spoilers don't produce much appreciable downforce: i'm just saying it's not going to do you much good against the lift which does occur in "high" ground clearance road vehciles like the RX-8...

for what it's worth, the air that gets pushed aside and not flowing under the car and swirling around under the car as well is probably worth more than whatever lift those things generate on the car, but that's just my humble speculating =)

Originally posted by wakeech
:p tell me how pushing air down (which results in an upward "equal and opposite reaction") reduces lift smarty pants... also, it reduces the negative lift effect the front of the wheel arch may generate...

but it certainly will cut some drag, diverting airflow away from the wheels :p You just said it yourself. They are vertical, so they mainly divert the air around the tires instead of pushing air down (there are no absolutes of course, but very little of the air coming in will be pushed "down" instead of "out"). I don't have any "Buger numbers" for you (especially since every car is going to be different), but I do know that car companies have experimented with them, and they found that they do work.

---jps