[skinrock]

I plan on buying the oem mtech kit, but I don't like the standard diffuser it comes with. What I really want is the IS style.

Does anyone know the part number for this diffuser that will fit the pre-lci rear mtech bumper?

reference pic: http://www.e90post.com/forums/showthread.php?t=540763

[skinrock]

I didn't realize that the performance rear bumper was for pre-lci as well. I'm thinking about getting that with the performance rockers and the aero front

[itrocks4u]

Can anyone please answer a stupid question for me and tell me what a diffuser is.

[skinrock]

Originally Posted by itrocks4u

Can anyone please answer a stupid question for me and tell me what a diffuser is.

It's the cosmetic piece running the length of the bottom of the bumper. The mtech bumper allows you to swap in a number of various diffuser designs.

[quattrosaint]

Originally Posted by itrocks4u

Can anyone please answer a stupid question for me and tell me what a diffuser is.

An actual diffuser is located on the back of the car (under the bumper on most exotic production cars) what it does is smooth out the turbulence of air leaving the under side of the car. When you are driving at lets say 100mph when air hits your front bumper, the portion of the air that is pushed under the car is compressed. When it leaves the bottom of the car through the rear the faster and more stable the air is the more downforce it causes without creating any additional drag. On Race cars, primarily f1 cars. The exhaust is actually used to heat the air molecules so they expand just before the air hits the diffuser. This makes the particles further apart (less dense) and allows the air to more more freely out the rear. That's the long answer to a short question lol