Let's Get Down

Found this gem about downforce in the Nissan Infiniti Car Owners' Club.

BrianHarte, one of the forum members, posted an informative Drift Tengoku article that ran a test on the different amount of downforce generated by different rear wings on a zenki S14

Here's the overall results as shown on the graph, plotting downforce generated (dependant variable) against speed (independent variable) up to 150 km per hour. As shown from the lowermost gray line, the stock s14 with no wing experienced negative downforce (i.e. 'lift') of almost 40 kg! Now you know why your car feels 'floaty' when you are zooming along the North South Highway...

From ascending amount of downforce generated, we have the following results:

Stock wing generates a measly 3 kg of downforce. Well I suppose its better than having lift...

B Wave wangan/whale tail wing generates a surprisingly high 36 kg of downforce. My guess is that Wangan style wings have to compromise between downforce and top speed.

The Cusco GT wing shown above generates decent downforce of 62 kg, about the same amount of stability you will get if you have an average sized passenger in your car. Now we are talking...

Another Cusco GT Wing, the '3D' model with higher stands (from what I can gleam from the Japanese words) tops the comparison with 89kg of downforce.

If you analyse the data, some important findings can be observed:

1) Whether ancilliary aero aids like front carnards generate meaningful downforce. The test car has front carnards but as you can see the wingless S14 is still experiencing lift. However, no test was done on a wingless AND carnard-less S14 so we can tell how much downforce the carnards generated on their own. But I will venture a guess that it's not that alot.

2) Automotive aerodynamic design has come a long way and performance cars nowadays generate downforce right out of the box. I tried searching for data on the amount of downforce a R35 GTR generated but could only find that it has a low "coefficient of drag of 0.27" and "negative lift (downforce) generated at speed". A more specific quantification comes from the Dodge Viper ACR which generates 1000 lbs (454.5 kg!!) of downforce at 150 mph (240km/h)!

3) The most important finding: Wings are functional even at normal driving speeds. A common misconception (which I have previously as well) is that wings only come into effect at high speeds. But the data show that at 90km/hr (expressway speeds in Singapore), a S14 with a Cusco 3D GT wing is generating 40 kg of downforce versus the wingless version experiencing about 15kg of lift! That's a significant difference of 55 kg at normal speeds...

Some would argue about GT wings being too ricer for day-to-day cars. While I wouldn't necessarily disagree, at least the data shown here is that they are without a doubt, functional.