Escort Aero
 

I just purchased an 89 escort 5 door and am becoming very intrigued by the aerodynamics of vehicles. Being am engineering student this stuff fascinates me.

I was wondering what aerodynamic mods my vehicle would benefit from, would a tail help it? Cause I thought angle looked pretty good already

this isn't my vehicle, but the best side pic I could find online

http://carphotos.cardomain.com/ride_...0001_large.jpg

belly pan, moondisks, and grille blocks... those are always good.

I think she may have too steep of a read window, and a boat tail may be in order. There was a Ford Pinto that was eco modded in the 70s and they used a spoiler lip to compensate for the steepness.


The major issue I see with her is the front windshield is way too steep. Adjust the angle about 10 or so degrees would help dramatically.

I know what you mean about the windshield angle. How could that be modified?
And what do you mean by a spoiler lip?

Her is a better side view and it's of my rig :)
http://www.surfphotosd.com/photos/785498168_Jojg9-L.jpg

I've owned 3 escorts, and got better fuel mileage out of them completely stock than any other vehicle I've owned since. (most of which were still 4cyl)

Yours looks to be sagging a touch in the rear. I'd boost that up, or of course most people are going to suggest pulling the front down a bit. Whichever.

My tempo's arse was sagging somewhat worse than yours and just replacing the rear springs/struts ($120 total) brought me from 24 to 31mpg on the same, repeated 240 mile, 75mph round trip. Both mileage #'s are dismal mostly due to 3-speed ATX & the high speed being traveled.

jmedia -

Looks like you already have "aero-friendly" wheels :

http://ecomodder.com/forum/member-cf...ser-wheels.jpg

Good 'ol 1980's-era pro-aero design subtext.

CarloSW2

A spoiler lip, or wing similar to what they use on nascar vehicles to increase downforce. In the case of the pinto it allowed the air to flow better than just dropping off. I suppose it had a minimal downforce effect, but also just enough turbulance to keep it going.

are the spoiler lips the smaller ones? Cause I've read spoilers increase drag

I think it was a small one (the lip spoiler). You could try a horizontal decklid extension too, would be safer - less likely to mess up and increase drag, like you mentioned.
That 'scort should get great MPGs; I would have bought one but like the looks and space of the newer (barely) one that I have.
Does it have a/c or power steering? If it has P/S, you could remove it to get 1-2 more mpg, as demonstrated on feoa.net by lots of people who have done it.
I think doing a bit of air dam/front belly pan work, rear wheel skirts, and deleting the passenger (and driver if you want!) mirrors would be your best place to start.
Welcome to EM!

jmedia -

I started with this image :

http://ecomodder.com/forum/member-cf...emplate-01.jpg

Based on this, I (arbitratily?) chose a rearward center of roof camber :

http://ecomodder.com/forum/member-cf...cort-89-01.jpg

In the above, the red vertical line is what I *think* is the center of roof camber. Maybe aerohead can chime in. Then I applied a personal rule that the spoiler should not extend past the rear bumper. That is how I defined the red box in the back. Where the red box meets the slope is where the spoiler should extend. By sheer accident, that line is the bottom of the van window behind your Escort. If I am correct in determining the "center of roof camber", then that leads me to this mock-up :

http://ecomodder.com/forum/member-cf...cort-89-02.jpg

I don't really like it, but there it is.

Again, if it's correct, then what I am suggesting *might* be the inspiration for the "Sierra RS Cosworth whale tail" :

Steve's 1989 XR4Ti
http://people.arsc.edu/~munk/89/rs-c...-sierra-03.jpg

A less(?) agressive solution may be applicable from the Merkur XR4Ti :

1987 Merkur XR4Ti - 1980S - Jalopnik
http://jalopnik.com/assets/resources.../Merkur_LH.jpg
http://jalopnik.com/assets/resources...r_Spoilers.jpg

CarloSW2

Oh wow CarloSW thanks for all that. I wonder if that is why they have those whale tails. I wonder if there is a way to test that. Or even somewhere to buy one.

And gascort ya I think I'm gonna start there, rear wheel skirts, not sure about belly pan, just not sure how to do it. As for the grill blocks I'm a bit nervous cause I live in sunny ca and I don't wanna over heat.
Lastly is the vehicle hard to steer without ps?

Thaks for everything everyone

jmedia -

That's why I hope aerohead gives his advice. He can tell us if I put the curve in the right place, and should know if the whale tale is aero or bling.

In terms of grill blocks, you can use cardboard or even painter's tape to test overheating. Get's hot, pull off tape in sections or cut holes in cardboard until it's "comfy". However, I am lucky because I have OBD-II in order to observe the exact coolant temp. I think only have a gauge, :( .

In terms of steering, you look to be in decent shape :

1989 Ford Escort Reviews by Cars.com Experts and Consumers
You could buy a manual-steering Saturn S-Series weighing in at 2300+ lbs, so 2258 lbs should be manageable.

CarloSW2

jmedia -

I did some studying of the whale tail that originated on the Cosworth :

http://ecomodder.com/forum/member-cf...osworth-01.jpg

When I apply the curve so that it meets the whale tail, I can see that the "center of roof camber" is farther forward than I chose for your Escort :

http://ecomodder.com/forum/member-cf...th-overlay.jpg

However, your Escort is a 4-door, and this is a 2-door, so it's not *that* far off. What's nice is that the Cosworth was definitely aero-inspired, so that gives us hope for the whale tail :

Ford Sierra Cosworth RS and Ford Sierra | Cars - Pictures & Wallpapers, Automotive News, High-Quality Images, Sport, Exotic, Luxury, Expensive Cars
Pictures of the Ford Sierra RS Cosworth - Motorbase


CarloSW2

oh Awesome! thanks for all that research. I wonder *IF* i was able to find a whale tail spoiler if it would fit on my 89....

jmedia -

Yeah, I was thinking about that too. At this location is lots of pictures of a restoration :

Steve's 1987 XR4Ti Project Car
http://people.arsc.edu/~munk/87/index-Thumbnails/23.jpg

My *guess* is that because the car looks a little bigger than your Escort, it will be wider, which would imply the need to cut out some of the middle. Also, I did a very rough analysis of the rear window slope, and they seem to be within 2 degrees of each other.

CarloSW2

I have a feeling the angle of your rear hatch glass may be in the "BAD" zone.

If I hadn't lent my Hucho book to Ben, I could verify the numbers!

But the idea is that as the rear angle descends from horizontal, drag decreases to a certain point, then increases dramatically at a certain angle (where strong C-pillar vortex formation begins to occur), and continues dropping again as the rear glass angle approaches vertical.

I think this would be ideal
http://www.surfphotosd.com/photos/786444226_9J6ad-L.jpg

if only someone sold it somewhere, i dont care how ridiculous it looks

actually probably more ideal if it tapered down at the end instead of up

jmedia -

I like it, but I don't think it will help for MPG.

CarloSW2

Oh really? too long? Ya i guess, no point then since my only goal is mpg. I've been looking for an excuse to try making something out of fiberglass, maybe this will be my chance :thumbup:

It's not too long, it's the wrong angle. It needs to taper down.

Do it!

See here for example: http://ecomodder.com/forum/showthrea...sion-3518.html

jmedia -

I didn't do any "teardrop curve" drawing/calculations, but I could imagine mounting it in a lowered position :

http://ecomodder.com/forum/member-cf...il-lowered.jpg

Some states have laws against extending things beyond your rear bumper, so this may not be kosher.

CarloSW2

Pffft! Laws!

I'm guessing there are laws about shutting off your engine while in motion too. :rolleyes:

Here I always thought those whale tails where nothing but silly. I'm almost shocked.

California can make a law about anything when it comes to driving :rolleyes:

and ya i know what you mean, i thought they were ridiculous too