[aerohead]

Originally Posted by 19bonestock88

So, I've been pondering the aerodynamics of my Malibu again(always seeking gains), and I'm working presently on a lip spoiler... Right now, I've got my old vortex generator array repurposed into the inner reinforcement for a lip spoiler... The thing is, I'm not sure how to optimize the design for aero benefit... Right now, the reinforcement is made up of triangles, roughly 1"x2", right triangles, meaning the spoiler rises at roughly a 30* angle, and has a hypotenuse of roughly 3"... The thing is, the trailing edge of the trunk is curved, and I would like to match it... Either I can curve the entire spoiler and complicate the build with a complex curved hypotenuse, or curve just the trailing edge of the spoiler, making it taller(and longer) in the center, and shorter near the edges...

Is a 30* angle suitable for aero, or should I change it now, before gluing the entire thing together? What would be the optimum height for it?

Back in 1974,CAR and DRIVER experimented with some home-built spoilers for their CRISIS FIGHTER PINTO project.They found a drag minimum when the rear spoiler had a 30-degree up-sweep.
Some have done like you're thinking about,using the spoiler to reach up to the template profile