If you want to be serious, the amount of downforce provided by a spoiler (assuming it is functional at all) is a function of speed, meaning there is really no "magic number" where the spoiler suddenly starts to work. It may or may not be a linear relationship, but its not like at 84mph you get 0 lbs downforce and at 85 mph you get 50 lbs downforce. The reason downforce numbers are quoted as such ("This spoiler generates 53 lbs of downforce at 90pmh!" for example) is that they have to quote something, or provide a graph, and it is unlikely that most aftermarket aero manufacturers have done that much R&D ($$$) to provide an accurate graph. Except maybe Mugen, because why else could their aero parts cost so much

 

flux capacitor sold separately

 

I think Mugen worked this piece out before they marketed it..


C-west is also windtunneled to create negitive lift at speed ---
they claim lift force reduction at 75mph to 90mph --- (w/out giving the lift units (at least not in the translated page)).

so at 75ish the frnt lift goes from +13.13 units (stock) to -11.48 units (w/kit)
and at 90ish the frnt lift goes from +23.65 units (stock) to -15.10 units (w/kit)



Mugen is also supposed to test their parts..

Splitters tend to work their magic better the further (to a point of course) they stick out infront of the main bumper mass and "split the high pressure zone directly in frnt of the bumper w/ the fast moving low P air moving under the car..

And the mugen doesn't look like it sticks out much --
but like I said, mugen is supposed to test their pieces -- maybe they've maximised the neg lift and minimized the rice..

 

Nice post.

I think I'm going to try out the APR piece. It sticks out a bit.