This is performance, Hear me out. Aero is performance right?
Here's your answer.

http://auto-racing.speedtv.com/artic...on-prototypes/


Quote:
... Louvers are used over the fenders of sportscars to relive high pressure that builds up from the fast spinning tire, and from the complex interaction of air flowing in, out, and through the wheel arch.

The general rule is the more air you can extract from the wheel well, the better. On street courses, prototype teams will usually sport the biggest, longest, and most aggressive forms of louvers to vent air and create downforce. Another aspect of most louvers is their taller height (to give air a ‘chimney’ to flow out from) – that extra height adds more volume to the outer profile of the car—making a bigger hole for the passing air to go over and thus reducing straightline speed. ...

Sooo, I'm vending my fenders. Thought I would share with the class....







I'm not done, of course. Trying to decide between louver vents, mesh, dimpled holes or what... any ideas?

 

Subscribed!
Good idea, good luck in that!
Maybe, my next mod?

 

Thats gonna be sick! Good work!

 

What you have underway will certainly create an area of low pressure, that creates a "sucking effect" that pulls air from the fender well area. This will produce better braking performance since you're removing the warm air/gasses produced when braking.

As far as how much air is being pulled out, or even your proposed down force increase is up for debate. The air flowing within your fenders is VERY turbulent. The race teams that you mention undertake an extensive engineering effort to optimize vents/louvers and aero (3D modeling and fluid flow/dynamics analysis). They do not simply start cutting and welding. With that being said, there actually may be a chance (a very slight one) that you may have hurt aero performance. Good luck and I can't wait to see the final product.

 

looking forward for the result too!

 

Kudos for trying this out with an eye on increased performance! I know there are a couple of people here with fender mods that look a bit similar to yours, but I don't think anyone has actual vents in the fenders.

At the very least, you are in good company, the new Porsche 911 GT3 RS has some sizeable vents in the front fenders:

 

I want some rear wheel well vents like that! ^