Mini Racecar Aerodynamics

My next area of attack was on the Aerodynamics.  The Mini has problematic aerodynamics to say the least.  I have several areas to improve, including a front splitter, rear wing, underbody airflow, rear diffuser and other aerodynamic aids.

A couple of years ago I had a splitter on the front - mainly for aesthetics. However I noticed that although it was not really functional (i.e. you couldn't properly adjust the angle or alignment), it did have a positive impact on high-speed stability. Moreover, given the fact that most of the weight reduction has been behind the center of gravity, I knew I had to compensate for the added front downforce with a rear wing that I could similarly adjust - both in angle & height. 

I was able to get both the splitter and rear wing fabricated by APR Performance. They produce real functional racing elements & were able to make customizations based upon my requests (e.g. making the rear wing 1' narrower than normal). 

Here is what the splitter looked like when delivered

I wanted to mount it in such a way as to allow the bumper to "float". By building a simple aluminum bracket, I was able to create a solid structure to mount it to that was also weak enough to bend/flex if I hit something:

The bumper slides in above this bracket and two adjustable braces connect through it:

The next area of attack was the rear wing.  I knew that by a proper placement of the rear wing I could also also reduce the drag on the rear end.  However it is difficult to balance both goals in a single wing element. So my idea was to use a double element rear wing. Here is a link to a simple CFD simulation I ran looking at the effects of a double element rear wing:

Here's a view of it sitting on the floor:

And here's the design I came up with  for the bracket to mount the rear wing:

With this arrangement I can control the vertical position, as well as the angle of the overall wing.

I'll cover the under-body and rear diffuser designs in a seperate post.

Posted on January 24, 2014 .