Improving aerodynamics with aftermarket parts

[fuscobal]

Interesting...had a discussion with Simon from Reverie today and looking at my pics he said my wing is almost in freestream and there is no way that I lose 25% of the downforce as compared to freestream. He said I may lose very little or nothing. In this case it's safe to replace the 30Kg value with a 40kg value !!!

speed  >>> stock lift >>> wing DF >>> Total 1 >>> wing + gurney DF >>> Total 2
in km/h . . . . . . . . . . . . . . . . . . . . . (wing DF - stock lift) . . . . . . . . . . .  (wing + gurney DF - stock lift)

   80 >>>> +5.92 kg >>>> -10.00 kg >>> -4.08 kg >>>>> -12.5 kg >>>>> -6.58 kg

 100 >>>> +9.25 kg >>>> -15.63 kg >>> -6.38 kg >>>>> -19.53 kg >>>>> -10.28 kg

 120 >>> +13.32 kg >>>> -22.5 kg >>> -9.18 kg >>>>> -28.13 kg >>>>> -14.81 kg

 140 >>> +18.13 kg >>>> -30.63 kg >>> -12.49 kg >>>>> -38.28 kg >>>>> -20.15 kg

 160 >>> +23.68 kg >>>> -40.00 kg >>> -16.32 kg >>>>> -50.00 kg >>>>> -26.32kg

 180 >>> +29.97 kg >>>> -50.63 kg >>> -20.66 kg >>>>> -63.28 kg >>>>> -33.31 kg

 200 >>> +37.00 kg >>>> -62.50 kg >>> -25.5 kg >>>>> -78.13 kg >>>>> -41.13 kg

[the bruce]

Revised my conclusion:  


1.
At 80 km/h it may be of lesser significience if you have 6 kg of lift on rear or -6.6 kg DF.

2.
At 140 km/h it definitely matters whether you have 18 kg of rear lift or you have -20 kg
of downforce instead, even more if you turn in and have still your foot on the brakes.

3.
If you apply the brakes at the end of start/finish, rear grip will be vastly improved.
37 kg of lift compared to -41 kg of downforce !! This is a difference of almost 80 kg at
a moment when dynamic corner weights are often below 100 kg !!!

With such a wing rear wheels of a FWD now have a chance to take part of deceleration.


again:  

[fuscobal]

Simon McBeath states in his book that a 2005 BTCC car has 1150kg and 38.9 to 61.9kg of downforce (3.4 to 5.4% of weight). By comparison, a LMP3 car has 605kg and 230.2 to 291.1kg of downforce (38 to 48.1% of car's weight)