S4gasbord

I have a crazy idea. You know that bit of black plastic in our rear bumbers between the exhaust ovals?
<img src="http://pictureposter.audiworld.com/23974/rs4_rear_diffuser_location.jpg">

I'm thinking of replacing that with a diffuser, similar to this:
<img src="http://pictureposter.audiworld.com/23974/ferrari_f430_challenge_rear.jpg">

Do you think there is sufficient depth in that area to put in an effective diffuser? Has anyone removed that black plastic piece to see what's behind it? &lt;flamesuit on&gt;

larryV

but you would have to incorporate a design that transitions aerodynamically with with the rear underbody bits and pieces, including the exhaust to make it functional. My M5 has a functional diffuser in the same area between the exhaust pipes and after putting it up on a lift and examining it, it was a well thought-out aerodynamic design that flows well with the flatness of the rest of the underbody. It also appears as if the rear diffuser is particularly focused on sucking most of the air from the rear differential to further promote cooling. Now the RS4 doesn't have as much power going through the rear differential as the M5 but it wouldn't hurt to have a similar design incorporated.

Speaking of which, doesn't the S4 25Q have a functional rear diffuser? Or was I seeing things that one time I saw it at the dealer?

Fluffhead

Great idea, but I think that and the bumper are one piece

James P.

Here is about the best pic I could find...
<img src="http://www.fourtitude.com/gallery/albums//Features/Road%20Tests/2006%20S4%2025quattro/003.jpg">

Der Kimbo

Already in Progress :-)

S4gasbord

:-O details please!!

superswiss

Or this one. Maybe not the best picture, but it shows how it looks like with quad exhaust on the 07.

<img src="http://pictureposter.audiworld.com/106279/diffuser.jpg">

RSfizzy

I'm in!! Details?

S4gasbord

Maybe not. There appears to be several screws holding it onto the bumper. Pictures to follow.

S4gasbord

Hmm, that doesn't look like a very effective diffuser.