Is there any data or does anyone know to what extent particular exterior modifications (namely various rear wings and front ends)modify downforce/drag and improve handling/top speed, etc. , or are they all relatively aesthetic.

For example, I read somewhere that the RUF rear wing provides more downforce in the "down" position than the stock rear wing does in the "up" position.

I assume there would be two categories to this question, i.e. those that reduce drag/downforce in order to increase top speed, and those that increase drag/downforce to improve handling.

 

A Gt-2 set up has more drag. High speed is greatly improved esp. when used with a better suspension. I think it really works, plus it looks great.

 

I think the 'common knowledge' about the aerodynamic effect of
one 'package' or one new part, is going to be about the most
untrustworthy of any of the 'anecdotal engineering' we share.
No one, not even some of the wing manufacturers it seems,
has the wind-tunnel and suspension load measurement tools
to get an objective sense of what aerodynamic changes actually
occur.
If the 'wing flavor of the month' manufacturers were trying
for performance, they would lead with their measurments of the
difference (trade-offs) in drag and downforce that a given wing
or air dam produced, but in fact these are primarily cosmetic "look
at me, I'm different and exotic" pieces, in my opinion.
Trade-offs are inescapeable. For instance, a set up that has
more drag will necessarily be slower at higher speed, but it is
hoped that the drag is being converted to down-force to plant
the rear at speed. It is also hoped that the car owner altered the
rear shocks and springs to handle as expected with the extra
hundred or more pounds of load from the downforce, or it is
just a matter of looking good as fast as you can...
IMHO,
Joe

 

Thanks!

 

I would add to the anecdotal body of knowledge that mixing and matching different nose and wing vendors on the same car can have disasterous consequences with resonant vibration at speed. Especially when you consider a lot of track events insist on open windows. therefore, it is quite possible to create a wind effect on the car that has NEVER been tested. This may be getting off subject a bit but there is one great example out there today of a German manufacturer that released a brand new car without any aftermarket changes and everyone loves it. But no one tested the car with the windows down. When you drive the car over 40 MPH and lower the rear windows there is a buffetting that causes actual pain in the ears. (Pacifica, my wife's car, this is no urban legend). The point is, you better be careful with the combinations. I have a 996TT X-50 with a Gemballa nose and a GT-2 rear wing. I love it. But occasionally when the track conditions are right, there is an air flow issue. My mechanic insists it has to do with the aerodynamic changes to the car and he states it is a familiar complaint that he sees.