Learn em: park bench for downforce.

When you see that cheap APC park bench on a car, you wonder about it's effectiveness. 
 

now, I realize that a company like APC (showing my age) never did wind tunnel testing. And this is why the park bench is only a few hundo, and not a grand. 
 

but does it produce downforce? Has anyone tested this? 

I expect it produces some, but has a pretty bad lift/drag ratio.

If you were building a cheap ass track machine, would you run one? (Not including the laugh factor from your fellow track peers...)

Not the most efficient, but they definitely produce downforce. I've used one on an autox car and it made a noticeable difference. A good friend of mine bought the same one I did. It produced enough downforce to collapse the uprights that held it up.

Anything with a roughly wing shape can make downforce, but as Seth noted it may make as much drag as downforce. The harder part will be getting it setup to work properly with little info on how it performs. There are some apps that can be used to convert a picture to a CAD representation that can then be used to do some simple analysis, OR you could just bolt it on and have more downforce than before and not worry about the drag side of things.

Keep your eyes open for the latest issue of the magazine...

Best way I've seen to evaluate wings is to start with a pretty low AOA and keep increasing it. As soon as lap times start to rise, you stop. 

My car can handle a pretty high drag level but can use more help in the corners. So I'd probably run one if I didn't have better options. But I'd be more likely to build my own or use something else. On a stock Miata, the drag would be more of a problem.

9lives Johnny in... 3... 2...

In reply to Keith Tanner :

Ok, Thats good info. Stock Miata. Autocross. APC park bench is more drag than downforce. 

Park benches make fabulous downforce.  Case in point....

In reply to Klayfish :

Cheap too. If you can work an angle grinder I heard they give them away in the local park. 

Keith Tanner said:

Best way I've seen to evaluate wings is to start with a pretty low AOA and keep increasing it. As soon as lap times start to rise, you stop. 

You need a driver who's WAY more consistent than me to do that, though. :)