Will
Dork
3/16/12 7:02 p.m.
I want some more grip in the rear of my ESP 4th-gen. We're just talking a NASCAR-style blade spoiler on the rear of the decklid, nothing fancy. I've read the rule book, so I know how I need to mount the spoiler, but I'm wondering what angle I should set it at. I've heard that 60 degrees is the best blend of downforce and drag, but I'm not certain that's the best setup for the low speeds of autocross.
What does the hive think? I'm especially interested to hear from any SP guys--I've seen plenty of Corvettes, Miatas, and so on with spoilers like this.
Spoilers don't have a huge effect at auto cross speeds unless they are huge.
Will
Dork
3/19/12 5:39 p.m.
I'm not planning a small one. The rules say I can go 10 inches high times the width of the car. I've heard from enough ASP Corvette drivers who like them to convince me it's worth a shot.
Make it adjustable, you should be able to hone in on the best angle for your application with a bit of skidpad testing.
Yeah, doing some actual testing and making the spoiler adjustable will be key. The optimal angle will be different for every car and course. I'd say 60 degrees is a good starting point though.
Don't forget to add some endplates if it's allowed in the rules. This will make the spoiler much more effective. Take a look at this for reference:
I don't know what the rules are in your class, but a raised airfoil (actual wing) is far more effective if designed properly, even at auto-x speed. Something like this is pretty ideal:
Will
Dork
3/19/12 6:28 p.m.
The SP rules state that it has to be a spoiler (not a wing), 10 inches tall at most, mounted to the rear of the decklid. Endplates are not allowed. As I said, this is a NASCAR style spoiler, nothing complicated.
Per Schroeder
Technical Editor/Advertising Director
3/19/12 7:37 p.m.
Most of the spoilers I have seen at a national level are pretty aggressive, nearing 90 degrees...
Oddly enough, so were the NASCAR spoilers. They'd only lay them back to reduce drag.
That's got to be a fun science experiment. Too much downforce and the fuel runs out before the tires do, too little and the tires run out before the fuel does... and the driver plays a big part of it, too.
My advice is run a high wing like a sprint car. Speeds at autox's are low and you will get massive amounts of down forces at low speeds.
That's not necessarily a good idea if it boots you to a much more aggressive class, though.
I'm adding a wing like this to my challenge corvette just to see what it does
