Wheel well vents

[spacemanspif]

I saw a WRX the other day and noticed that there are vents at the rear of the front wheel wells. I've read tips about aero and remember seeing that radius'd (Is that a word??) wheel wells are better. I'm guessing this is because air can be "caught" by the rear of well and cause more drag? This got me wondering if the WRX vents actually work and if other cars with bulging fenders could benefit? The new beetles come to mind first but I'm sure there may be others. Can anyone weigh in? Am I on the right track or more confused than I thought?

Reference pic:

[jedi_sol]

The wheel vents are purely cosmetic...there is nothing behind it

Yes, i've come to the same conclusion as you. I plan on removing those "vents"...and then fiberglassing a smooth radius transition aft of the front wheel well on my sti

however, not sure if it will give me any benefit

[renault_megane_dci]

I have seen whee well vents on several cars and also wondered about their effect.

The wheel well is a vacuum place as far as I know (setup used to cool Austin Minis) so a vent at the back does not sound like a good idea unless the front end of the car is designed to pressurise the wheel well.

Thoughts ?

[aerohead]

The USA version is Cd 0.30?
The 1986 Subaru XT was Cd 0.29.
The 1982 Firebird Trans Am extractor vents ADDED drag but were left for aesthetic reasons.
Professor Alberto Morelli's handling of the vents on the CNR 'banana' car would be the global benchmark for vent efficiency.
Tricky stuff!

[Vman455]

These vents were real; they vented the engine compartment, not the wheel well, and I don't know how effective they actually are. I'd bet this is the same on most sports cars with this feature, or nonfunctional and cosmetic. The outgoing Mercedes E-class vented the rear wheel wells, exhausting that air through vertical slits on the taillights.

[mcrews]

that is such a badass car.... ......(sorry I digress)

[Xist]

So, you drive with your window down and you have your engine venting in front of your door?

[aerohead]

Originally Posted by Vman455

These vents were real; they vented the engine compartment, not the wheel well, and I don't know how effective they actually are. I'd bet this is the same on most sports cars with this feature, or nonfunctional and cosmetic. The outgoing Mercedes E-class vented the rear wheel wells, exhausting that air through vertical slits on the taillights.

I think the Viper has the same Cd as the RAM 1500 pickup,so I don't know how much good the extractor vents did for the car.They're never used in low-drag concept cars,except the 'banana' car.And at Cd 0.201,the 'banana' car is kinda at the high end of low drag.

[renault_megane_dci]

What about the Viper's rear vents ?

[aerohead]

Originally Posted by renault_megane_dci

What about the Viper's rear vents ?

*They're right at the rear separation line and hopefully emptying into the wake.
*If the pressure at the rear wheels wells is lower than that of the wake's base pressure,then air would actually flow forward into the 'extractor.' You'd have to be vary careful.And something you could only do in a wind tunnel.