Short Skirts?

[vtec-e]

Originally Posted by Xringer

So, should I give the mini-skirt a try?

Should we be getting worried??

ollie

[Xringer]

Originally Posted by NeilBlanchard

Hiya,

I think that skirts will function better is they cover as much of the wheel opening as possible. I tried some smaller skirts (because forming a curve in them was not possible) and now I have Coroplast skirts that "connect" the lowest part of the opening, and they are helping a bit more to improve the MPG.

I'm just looking for the easy way out..
If I can figure out a way to get full coverage, I'll do it.
But, if it turns out to be a lot of trouble, I'm pretty sure the shorter skirts
will work better than nothing at all.

[vtec-e]

The mini skirt might be a good job alright. You could find that most aero gains might be made with a mini skirt. The advantage of a mini would be being able to change a wheel without having to remove the skirt. Which also means the skirt can be made more secure/permanent.

ollie

[Xringer]

Originally Posted by vtec-e

The mini skirt might be a good job alright. You could find that most aero gains might be made with a mini skirt. The advantage of a mini would be being able to change a wheel without having to remove the skirt. Which also means the skirt can be made more secure/permanent.

ollie

I was thinking of making it short, but about 1/2 way down.
That might be too low to change a tire. Flats are so rare anyways
(I never go off-road or drive in industrial parks), I'm not real
worried about flats.

[cfg83]

Xringer -

Here's the answer from one of the designers :

Short version would likely be that there was a point of dimishing return on the length.

Everything on that car was an issue of weight (each system team received an allocation of weight in grams), aerodynamics, and cost- with the first two very much taking precedent. Folks are right to speculate that for the skirt to have been longer and follow the body of the car, it would have had to curve in, hitting the wheel itself. So to make it longer, it would have had to curve out, increasing the drag and defeating the purpose. Also, the rear wheels were about 7" closer together than the front wheels, giving yet another curve to deal with. At the end of the day, the EV1 was the most aerodynamic production car ever built, with a drag coefficient of .19- when you get that low, squeezing out any more becomes that much more difficult.

Your friend might be interested in reading a fascinating book about the development of the EV1- it's called "The Car that Could", by Michael Schnayerson.

EDIT: Here's the book :
http://www.amazon.com/Car-That-Could.../dp/067942105X

CarloSW2

[jwxr7]

I went with mini skirts because they were way easier to do on my car and I think I can still get the wheel off with out removing them (I think? I have never tried). I went down as far as I could easily go (maybe 2/3rds). I would have had to do some bulging and curving of the coroplast that it wasn't willing to do at room temperature to make full skirts.

The wheel will drop quite a bit lower when you jack it up too, so that helps expose the lug nuts.

I never did tests on that mod by itself to see how much they help FE, but I have to imagine that it must be better than no skirt.

[jwxr7]

Here's an image of one of my coroplast miniskirts. I wasn't too worried about lugnut access in the beginning, but ended up with plenty of access anyway.

[Xringer]

" Folks are right to speculate that for the skirt to have been longer and follow the body of the car, it would have had to curve in, hitting the wheel itself. So to make it longer, it would have had to curve out, increasing the drag and defeating the purpose."


Thanks! That explains it very clearly. Making me lean towards the shorties..
When I told my wife the plan, she gave me that 'look' and said "WHAT?"..

[cfg83]

Xringer -

Originally Posted by Xringer

" Folks are right to speculate that for the skirt to have been longer and follow the body of the car, it would have had to curve in, hitting the wheel itself. So to make it longer, it would have had to curve out, increasing the drag and defeating the purpose."


Thanks! That explains it very clearly. Making me lean towards the shorties..
When I told my wife the plan, she gave me that 'look' and said "WHAT?"..

Hee hee hee, I know that look only toooooo well. I'm so lucky she puts up with me, !

CarloSW2

[Xringer]

Originally Posted by jwxr7

Here's an image of one of my coroplast miniskirts. I wasn't too worried about lugnut access in the beginning, but ended up with plenty of access anyway.

That looks about like what I'm thinking of..

That open area above the tire needs some blockage!!