MINI Cooper S rear diffuser w/ underpanel

[curv872]

The width of the Exhaust cutout lended itself to placing a strake on either side to channel airflow, the others are equidistant apart for asthetics.

The strakes probably do several things, but one of the most obvious is that they prevent low-speed, high-pressure air getting in along the sides of the car/tires from disturbing the flow in the central area of the diffuser.

Originally Posted by tugboat

What guided you on how many strakes and where to put them (or spacing them, or something )

Looks very factory, I agree. Well done!

[minAirForce]

this looks professional. How'd you make the strakes. They don't look like coroplast???

[curv872]

Originally Posted by minAirForce

this looks professional. How'd you make the strakes. They don't look like coroplast???

...they are coroplast pieces folded in half so bottom edge is perfectly flat...which also made them much more rigid.

Great tips for working with coroplast

[curv872]

Close up detail of the strakes

[curv872]

And from the side

[InsightfulRay]

Really appreciate your posting the pictures. That makes it clear as glass how to whip one of these up. I'm going to make one for my 09 Mini.

[minAirForce]

How are the vertical strake attach to the coroplast. Just glue. Isn't the coroplast too flexible? Does it buffet around?

[minAirForce]

Thanks so much for the coroplast tips!!

[Christ]

Are you planning any treatments to the rear inner fender area? There's a glaring hole in the last pic. lol

[curv872]

Originally Posted by Christ

Are you planning any treatments to the rear inner fender area? There's a glaring hole in the last pic. lol

The thought had crossed my mind, but it's not really necessary. The inner fender hole allows adequate ventilation for the rear exhaust and rear brakes. The strakes prevent most of the turbulent air from disrupting the flow of clean air through the diffuser.