Based on my simple test 60 kg = 11 on the meter. This works out to 5.45 kg per unit of display. I will probably need to check this a bit more by adding weight to when the display just changes, however as a guide it will do. Further the force is also relative as there are other factors that will affect the readings, however the way I mounted it should hopefully have taken some of the variables out. But some of the load is distributed to the rubbers around the boot, hence the force is only a relative one. It could be more accurate if I put the weight on the wing itself (a Sunday job).
Photos of how I got the value of 11.
I tested the wing at a few different angles and the results were (my speedo is a bit out however 130 is about 120):
0 Deg - 4 at 110 and 8 at 130. Therefore at 130 = 43.6 kgs of downforce
6 Deg - 4 at 110 and 9 at 130. Therefore at 130 = 49.1 kgs of downforce
10 Deg - 7 at 110 and 11 at 130. Therefore at 130 = 60.0 kgs of downforce
Based on the above I would say 10 Deg is a good starting point for the moment as the chances of going over 130 on public roads is well not smart. The 10 Deg generated a measure of 3 a 90 and 5 at 100 so it is giving some downforce, however drag is another thing.
Set up (the ARC has 2 sensors that measure the force on them, I put a domed head nut on the mounting of the APR wing and adjusted it so that when the boot closed it put pressure on the sensor - note the depression from the dome nuts).
Final setup 10 Deg
All the photos are here https://plus.google.com/photos/115769813738304087848/albums/5809064544034451409
Doing this exercise made me realise that some people have no idea the difference between a spoiler and a rear wing. Most factory spoilers must do very little and the ones that just add a spoiler are doing it just for looks. My next bit of fun is to do some wool tuff testing (plus it is an excuse to use the Contour Plus 2). If people in Brisbane want to have a play with the ARC Downforce Meter just send me a PM it is very simple to setup and get going. Just remember the measured forces are relative.
