FINALLY got the coroplast- Now to make the pan.

[Hermie]

Now that I've ordered some coroplast (finally found some from a sign shop, had to pay $13 per sheet, though), I'm going to be smoothing out the front underside and deleting the horizontal stock air dam under the radiator, similar to this mod:

http://ecomodder.com/forum/showthrea...els-10638.html

I'm going to be leaving a little lip sticking out the front, though, to act as a small splitter. I'm going for both drag and lift reduction! XD
You can see the stock flap sticking down in this pic:


I'll also be covering the gigantic opening on the rear with a sheet, because you can see here how aerodynamically dirty that is:


I'll also be using the scraps to close the rear wheelwells, and get the front tires out of the airstream. Currently, I have tire spats on all 4 corners, with the front ones made from the excess of the rears after I trimmed them down:
Front:


Rear:


I already have a lip spoiler and vortex generators, but I need to get some more of the adhesive and move the VGs back a bit, since at their current position I'm getting rather large counter-rotating vorticies. Apparently very good for lift reduction, but I'd like a little bit of drag reduction as well.


The material should be here Friday, so over the weekend when I'm not studying for final exams, I'll be under the car cutting, drilling, and smoothing.

Oh, is 4-mil coroplast thick enough?

[thatguitarguy]

Originally Posted by Hermie

Now that I've ordered some coroplast (finally found some from a sign shop, had to pay $13 per sheet, though)
I already have a lip spoiler and vortex generators, but I need to get some more of the adhesive and move the VGs back a bit, since at their current position I'm getting rather large counter-rotating vorticies.


The material should be here Friday, so over the weekend when I'm not studying for final exams, I'll be under the car cutting, drilling, and smoothing.

Oh, is 4-mil coroplast thick enough?

Around here $13 for a 4x8 sheet isn't bad, 4mm is standard and should be fine.

How do you know about the size of the vortices? Have you done tuft testing? Do you notice a difference? I've seen other shark fin VG installations where they are inline at the center and then angled out increasing the angle as they get closer to the side of the car. From the angle of that photo it looks like yours are all inline?

[Hermie]

They're angled. I have a better pic of them, which I'll upload in a little bit. The middle 4 are at 15 degrees, the next pair at 10, next at 5, and ends at 0. I'm going to reduce the angles of all but the middle 2 and move them back half an inch or so and see what that does, if I can get more of the adhesive pads they came with. I'm not too keen on ordering a whole second set just for that...

I have done tuft testing, and it's quite easy to see when the back glass is wet, too. It even forces water droplets into the swirl shape. Don't have any pics of that, though.
On the trunk, the tufts all spread outward from the center up against the glass (just in front of the middle brake light), spreading in the direction of rays in kid's sun drawings. You can tell it completely killed the area of low pressure behind the back glass, but it's adding to drag from the large counter-rotating vorticies. In other words, I'm sure I have extremely effective lift reduction, but almost no drag reduction. Mileage doesn't seem helped or harmed with them.


Here's one of the pics: