I have done a little bit more work on the Canards. I have created a bi-plane version with a smaller secondary item that sits higher. There is quite a bit less space here so I had to reduce the chord.
The design is starting to flow quite nicely with the sharp edges matching the rest of the car and the endplate detail returning on the splitter. The additional element provides extra downforce due to a local suction and pressurisation increase. It also yields a further improvement in downstream flow management by improving the energy near the bottom of the tyre and a little bit more adjacent to the wheel. The illustration below shows the flow energy distribution with no canard on the left, one canard in the middle and the bi-plane two canard setup on the right. High energy in red and low energy in blue.
Ever since I started posting here I have had a lot of interest. So first of all thanks very much for all the replies and private messages it is much appreciated.
The design of the canards are getting more and more finalised. Based on the amount of positive feedback and interest I am considering selling these to our Z4 community!
If you would be interested and haven’t already let me know could you please reply or send me a private message? If you would like to see tweaks to the design or have any recommendations then please get involved as well! The next step is to increase the size and width.