Del Sol Aerodynamics

[Compaq888]

Originally Posted by krousdb

I cant go any lower because the body tapers in and the cover will hit the tire. Yes, I will be doing the underbelly pan too. Just need to get my hans on the coroplast.

then use metal since it bends. Make it bend around the tire.

[SVOboy]

I think he means the wheel well will hit the tire.

[n0rt0npr0]

if you have home depot or lowes in your neck of the woods you can get that Coroplast there

AND FYI those of you wanting to use this stuff for the underbody belly pan...

When force drying in conventional screen jet-driers, temperatures should not exceed 100 degrees F (43 degrees C). Higher temperatures will tend to warp or distort the Coroplast sheet.

[MetroMPG]

Originally Posted by krousdb

I cant go any lower because the body tapers in and the cover will hit the tire.

i had the same issue with mine. i took them lower by forming a curve in the cardboard (which you can do with whatever material you end up using). the curved shape in my "experimental" cardboard units was retained with a piece of coat hanger wire duct taped to the inside (back) of the skirt.

photos: they make the skirt look flatter than it really is, but see...

http://www.metrompg.com/posts/grille-blocking-part-2.htm

also, i used the rear mud guards as part of the "structure" that supports the rear/bottom part of the skirt. without them i would have had to form a complex curve to get the skirt around the rear of the tire and back to the bumper.

if you remove the guards, you lose that option. and i suspect the aero penalty of leaving the guard on is trumped by the larger benefit of a full skirt.

[Flatland2D]

Here's a few of my experiences driving my Del Sol, but nothing real significant that hasn't already been mentioned.

Air coming over the targa top wants to loop back around and enter inside the rear window. I've noticed this when leaves have fallen on the trunk. When I drive off with the windows down I get a car full of leaves.

Just cracking the side and rear windows is enough to get a good amount of airflow through the car. Without cracking the rear window, the difference is definitely noticable. I have also wondered if this would acually help MPG by filling the vacuum behind the rear window. Hopefully I can test this someday.

I haven't noticed much difference in MPG with the top on and windows up as opposed to top off and windows down. However, this wasn't the most accurate test. At the time I was only getting 25MPG highway with 87 octance gas. Check engine light came on for fuel system. Later I learned a little more about my engine (B18C1) and found out it required premium (I started it out on this when I first bought it, but didn't know it was required and used regular gas). Anyway, two hours of highway driving in each configuration yeilded the same MPG. If I had a better way to test this there would probably be some measurable difference, but I didn't find anything significant. Went back to premium and fuel economy went back up (~35MPG highway).

I've also tried to think of ways to fill in the void behind the rear window with some kind of cover, but there is the trunk problem and the device would have to be clear. I think we're pretty much stuck with that unless someone really wants to change the look of their car. If it bothers you that much, then a '92-95 Civic would be one's best bet for aerodynamics (one of the lowest CD's of cars in this price range).

[krousdb]

Originally Posted by n0rt0npr0

if you have home depot or lowes in your neck of the woods you can get that Coroplast there.

I have both in my neck of the woods and neither have it nor have they ever heard of it. I ended up getting some today at a sign shop. Guess I will work on it this weekend.

[krousdb]

Originally Posted by Flatland2D

Here's a few of my experiences driving my Del Sol, but nothing real significant that hasn't already been mentioned.

Air coming over the targa top wants to loop back around and enter inside the rear window. I've noticed this when leaves have fallen on the trunk. When I drive off with the windows down I get a car full of leaves.

Just cracking the side and rear windows is enough to get a good amount of airflow through the car. Without cracking the rear window, the difference is definitely noticable. I have also wondered if this would acually help MPG by filling the vacuum behind the rear window. Hopefully I can test this someday

Yes, I have noticed the same thing. I believe I mentioned earlier in this thread that I have already tested the effect of opening the rear and side windows. I placed rows of yarn across the front, center and rear of the trunk lid. As soon at you start moving, the end row of yarn points to the rear while the yarn on the middle and front rows flip backwards toward the from of the car. I treid all combinations of opening windows and removing the roof and in none of the cases did it cause the front and mid row of yarn to flip toward the back. So I have concluded that the added drag from opening the windows will not help reduce drag at the rear.

Ryland suggested a spoiler at the roof angled down. Might have possibilities.

[krousdb]

So I got some coroplast yesterday for the underbelly tray. I have spent lots of time on how to approach it. I ended up buying four 2'x 8' pieces and paid $40. No, Lowes and Home Depot do not carry coroplast in my area. I have been to five stores and people have no idea what I am talking about.

The del sol has a black moulding that runs on each side under the door that runs from the back of the front wheel well to the front of the rear wheel well. This moulding screws into frame with 5 or 6 screws. These screws will make a great attachment point for the coroplast. I will start on the drivers side 2ft wide from the rear bumper toward the front of the car, as far as 8ft will go, attaching with the moulding screws and into the lip of the rear bumper. I just have to figure out how to secure the other two sides. What I will end up with is the left and right side covered with about a 1ft strip down the middle that will not be covered, mostly because the exhaust runs down the middle and I dont want to start a fire. Hopefully I can finish it this weekend for testing next week.

Wish me luck.

[SVOboy]

I ended up buying four 2'x 8' pieces and was raped to the tune of $40.

Would you really consider 10 bucks for a sheet of plastic you chose to buy and accurate comparison to rape?

[krousdb]

Originally Posted by SVOboy

Would you really consider 10 bucks for a sheet of plastic you chose to buy and accurate comparison to rape?

I was venting because paying $40 for something that would cost $24 had it been available in my area at Home Depot seems excessive to me. Yes it was my choice so rape was not technically a correct way to put it. If you were offended then I apologize. I will edit my post.