Del Sol Aerodynamics

[MetroMPG]

yay! krousdb is going to mod up his aero stuff! (we'll have rear wheel skirts on that puppy before you know it!)

Originally Posted by krousdb

I was thinking about a few options for smoothing out the turbulence, both which would leave my trunk unuseable.

you need a third option that preserves trunk functionality like this one i've been thinking about: an inflatable plastic shape that you can blow up like a beach ball, or with a 12v compressor, for use on highway trips. when not needed or wanted, deflate and store in the trunk.

in my wacky aero daydreams, i envision making an inflatable "boat tail" for the back of my car, to taper the flow a little further to reduce the cross section area where the flow separates. it would be lightweight, using straps to attatch to the hatchback edges (top & sides) and the bottom of the bumper.

the challenge is: (a) finding some material like the kind that air mattresses are made from that you could somehow heat bond the edges together; (b) for larger structures, you'd need to build internal baffle-like structures that would serve to tension the shape and keep it from "ballooning" in the pressure differences it's exposed to. (think of the shape of a convertible roof at highway speeds - not at all what it looks like when parked).

of course, a smaller inflatable shape on the deck of the del sol wouldn't have as much difficulty retaining its form compared to the big boat-tail needed to "fix" my upright hatchback design.

First I could install a clear flat plastic plate that would close in the area between the side butresses, the roof and the trunk lid. This would give me some transition from the roof to the trunk lid instead of the cliff that I have now.

i have read that you don't want to transition more than 11 degrees from the top or sides, or you end up with flow separation again. which means you may not be able to taper down from the roof edge right to the very tip of the trunk deck.

i suspect the optimal shape you end up with, observing the 11 degree limit, will have your taper ending some height above the trunk deck. surprise: it looks something like the back of a crx, prius or insight.

[krousdb]

Originally Posted by MetroMPG

i have read that you don't want to transition more than 11 degrees from the top or sides, or you end up with flow separation again. which means you may not be able to taper down from the roof edge right to the very tip of the trunk deck.

i suspect the optimal shape you end up with, observing the 11 degree limit, will have your taper ending some height above the trunk deck. surprise: it looks something like the back of a crx, prius or insight.

Right you are! The roofline is 11" above the trunk lid and the end of the trunk is 42" from the end of the roof, giving me a 15 degree angle. For an 11 degree angle, the tail would need to end 3" above the trunk lid.

[krousdb]

Hmmm. This might not be that bad looking after all.

[kickflipjr]

Not you too...

Wouldn't it be awesome if someone sold aftermarket wheel skirts that looked good. They could start with making them for civics (because they make every aftermarket part for civics).

Oh that cardboard dosen't look too bad. It would look better if it was red and made of steel

[krousdb]

Originally Posted by kickflipjr

Not you too...

Wouldn't it be awesome if someone sold aftermarket wheel skirts that looked good. They could start with making them for civics (because they make every aftermarket part for civics).

Oh that cardboard dosen't look too bad. It would look better if it was red and made of steel

I have a can of color matched spray paint so they will be red. Im thinking corrugated platic if I can get my hands on some.

[MetroMPG]

woo-hoo! another convert!

(i figure if i get enough of you guys adding wheel skirts, mine will become a little less conspicuous. no? didn't think so.)

[krousdb]

Kinda looks like an Insight doesnt it?

[Compaq888]

your design looks okay but the cartboard should go further down, and should flow with the rest of the body instead of just being straight. How come you aren't doing any under car airdonamic stuff? Lowering your car will just make the air more violent under the car. Get everything sealed under the car and you should see another couple of mpg.

[Matt Timion]

Originally Posted by MetroMPG

woo-hoo! another convert!

(i figure if i get enough of you guys adding wheel skirts, mine will become a little less conspicuous. no? didn't think so.)

This summer I plan on learning how to fiberglass. I'll then produce myself a set.

So is it generally accepted here that the mudflaps HURT aerodynamics? I'll remove them in a heartbeat if they do.

[krousdb]

Originally Posted by Compaq888

your design looks okay but the cartboard should go further down, and should flow with the rest of the body instead of just being straight. How come you aren't doing any under car airdonamic stuff? Lowering your car will just make the air more violent under the car. Get everything sealed under the car and you should see another couple of mpg.

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.