Now that I think about it, the rear of the trunklid on my '86 TBird Turbo Coupe kicks up and then drops off sharply. Was this a aero trick Ford used on the car that is credited with starting the "aero" design trend ('83 TBird) in the U.S.?
"If the engine ain't running it ain't using gas!"
As far as testing various vgs and ideas.... what's the issue with testing....except for the time involved?
That's it, basically: time.
I'd just rather focus on things that have a known effect for my hatchback car, before looking at things that may have some effect, but for which there's precious little technical info available, and no evidence (that I've seen so far) that they would work for my style of car.
Just to be clear, ZugyNA, I'm not debating that VGs work, when properly situated on a 3-box vehicle, with the right angle of the rear glass. And there seems to be little doubt that they help at higher wind speeds in aeronautical applications.
But back to cars - aside from the specific 3-box vehicle application, I just haven't seen anything more... rigorous.
There are no details of controlled tests anywhere on the airtabs website. When you look up "tests", you get "testimonials" - not at all the same thing. They mention a UK controlled test, but offer no details about it.
I'm not opposed to the idea of trying them out for the heck of it, and my mind is open to the possibility that they may have some effect on the back of my car. But I have half a number of other things I'd rather do first, is all.
Zugy (and others): Earlier today I e-mailed the company that sells airtabs asking about the UK study, and lo and behold, I just heard back from them. They attached a copy, which i haven't read yet. But I will have a look and get back with more info.
I may also move these posts into a new thread, since VG's aren't exactly on topic here in "Rear spoilers". (Sorry for hi-jacking your thread, Kraig.)
Here's something to talk about. What do you guys think would be the best way to fabricate a lip spoiler for the trunk lid that doesn't look like a complete disaster? (Read: no cardboard or duct tape )
If the spoiler can be straight, I was thinking about finding someone with a metal brake to bend something simple out of aluminum sheet. It could be done with two or three bends depending on whether you want it to wrap around the back side to be extra-secure or just sit on top of the lid. The only problem with this is that if you want to form the spoiler to a lid with a curved edge (in the horizontal plane as well as vertical), the brake wouldn't be able to form the metal in the second dimension. So for me that's out unless you guys know of some magical technique that I'm not aware of?
Another option would be to form it out of multiple strips of aluminum, cut to match the curve and welding or brazed to make it whole. However I've never welded or braized so I have no idea if that's really a viable option.
And then we get to other options that get a little more creative. For example, I do have several sheets of 6mm coroplast. Maybe I could find a way to cut and form that stuff to the shape that is needed? Perhaps some creative handywork and covering material could produce something that doesn't look like I made it out of coroplast and stuck it to my trunk lid?
I would suggest fiberglass. Luckily I don't really have this issue as there are little wings mand for the crx that match the body to extend the flow and blah blah blah, based on talking about it and looking at the little images of shapes in airflow it looks like it would work.
But yeah, I think make up a coroplast model and then fiberglass it. Coroplast is bendable with heat and all that, so yeah, not to mention cheap and smooth.