Rear spoiler angles for autocross...

[Darren Cole]

Does the big spoiler actually increase downforce or reduce lift? I think it technically reduces the lift caused by the air flowing faster over the top of the car, i.e. the instability that Mako was talking about.

[Bob Beamesderfer]

Does the big spoiler actually increase downforce or reduce lift? I think it technically reduces the lift caused by the air flowing faster over the top of the car, i.e. the instability that Mako was talking about.

Depends on the car, depends on the speed. With the Audi TT, the rear end lift occurred at speeds below the limit set for U.S. market cars, but it was above 120 mph. Car was voluntarily recalled for the addition of the spoiler and a suspension tweak of some kind.

[Steve Ekstrand]

Didn't they add a big lead bar to the back of Audi TT's???

[Roy Butler]

Does the big spoiler actually increase downforce or reduce lift? I think it technically reduces the lift caused by the air flowing faster over the top of the car, i.e. the instability that Mako was talking about.

That's a good point - just throwing in a huge drag element like the TVR Sagaris wing appears to be would slow the flow over the top, in relation to that underneath the vehicle, causing "suction" under the correct circumstances, right?

My guess is that one of the circumstances would include that the flow is not so wild over the top as to create instability...


Roy

[Bill Schenker]

Didn't they add a big lead bar to the back of Audi TT's???

No, I believe they removed the oem rear spoiler and put in it's place an approximately 3" piece of duct tape...