Its apparently an FK diffuser, I've seen similar looking ones, but never with the center 'hump', usually its got 2 little braces that would meet the underside of the bumper where the edges of my 'hump' looking thing start.

Paid $25 for it, then an additional $70 to ship it, plus some of the $100 quart of paint I had bought to do some touchup work on the car. Turns out the paint doesn't quite match, but you can't tell that close to the ground, reflections and whatnot help mask the difference.

http://img412.imageshack.us/my.php?i...scf0006on6.jpg

http://img409.imageshack.us/my.php?i...scf0007bv4.jpg

http://img412.imageshack.us/my.php?i...scf0008pn9.jpg

It really helps to throw road grime onto the back of the car, very evident by the pics. BTW, sorry for the dirty car... ; )

Kinda cool watching how many leaves and stuff it picks up in the fall, a noticable difference from before it was installed.

 

What's the purpose of a rear diffuser? Protect the exhaust tip? Aesthetics maybe?
Anyway, is that snow from CO or NY?

 

poor audi TT thats why i store it in the winter...lol although i could still be driving it now cause it hasnt even snowed yet global warming man!!! or something

 

simply put, it changes the air speedsto create more downforce giving better grip.

to be more technical:

A diffuser is defined in the automotive context as the rear region of the underbody that incorporates an increased angle, with respect to the ground, compared to the main, flat part of the floor pan. It effectively acts like the divergent part of a venturi, with the flat floor as the throat and the car’s slightly upturned nose as the convergent section. The purpose of the venturi is to return the airflow beneath the car to atmospheric pressure as smoothly as possible, which does two very important things. Firstly, smooth air from a diffuser will not separate as early as it would normally and will therefore produce a smaller wake and should reduce drag slightly. More importantly, as the diffuser has an upswept, expanding shape, air flowing under the car will be forced to accelerate through the throat to fill it, thus creating a low-pressure region below the car and effectively sucking it to the ground. The down force effect of a diffuser is dependent on a combination of angle and length, the shorter it is the greater the angle must be to maintain the same downforce.

 

Makes sense, thanks for clearing that up!

 

i do my best for fellow silver tter's

 

Heheh, yeah, but I think for the most part, this one is for looks. I mean, I mentioned I do see more stuff being picked up off the ground, so it IS doing something to the airflow, but I doubt any science went into the design. I would like to smooth over more of the underside of the car, and add some channels to smooth the air going to that diffuser, most likely after the muffler is deleted, and I go with a custom exhaust.

If I had my way, I'd model the car after the DTM version, unfortunately though the fender exiting exhaust is illegal in NY - possibly - I'd have to get a promise from a inspection shop that they'd allow it, it could go either way, depending on how strict the place is. The rest of teh body work, I could probably handle on my own. I'm a welder, I have metal working skills, and I have huge Abar vacuum furnaces that regularlyanneal aluminum, so shaping metal diffusers, fins, etc ispossible, maybe not easy, orsmart, but it could be done.

As for driving in the winter, I'd rather not do it with the TT, but until the other car is reliable, its all I have. It does have its moments though. I just learned the best gear for donuts is 2nd. Speedo was reading about 45mph, even though I was only moving in a tight 10' circle. Tightest circle I could do with the conditions.

 

i am in pain just looking at the shape of your car right now

 

Man i love those rims.
They scream honda civic hehe.
Just kidding i know there winter rims.

 

Well, its about to get cleaned up and presentable, I have to go get my car re-quoted for repair work, to fix the repair work that the other shop did after i banged it up.

This is actually a high end euro repair shop, and the TT needs to be as classy as I can make it with 16" steelies : (