Ford Escort ZX2 Aerodynamics

[redneck]

.

Originally Posted by BabyDiesel

The wheel skirts failed beyond miserably As soon as I turned onto the road, the back fell off the rear tab and it was in contact with the sidewall for 1/2 a mile, aluminum rod and all. If I had done my 4 mile test, the tire would have blown out!

It turned out that the hinge is flexing and not keeping the skirts within its tolerances. So this idea is done, and I will be driving to the beach with my same 0.269 Cd lol.

Instead of front wheel skirts, try using a wheel arch gap filler. You already have the mounting brackets installed. Just cut some coroplast or foam to fit. Then screw and or tape it in place.

That's what I did.







No complicated front skirts.

If it's good enough for VW and their flagship XL1, then it's probably good enough.









>

[BabyDiesel]

I had not considered that idea recheck! Thanks for the idea. I will see if I can work some tight tolerance filler gap fillers when I get back from vacation

[BabyDiesel]

I'm finally back from vacation and have gotten some much needed work done to the ZX2!

In my talk with Tygen1 yesterday, we got on the topic of aerodynamics and their effect on lean burn operation. We discussed what we had, and I mentioned that I removed my air dam in favor of a belly pan and to decrease my frontal area. He came back with a lightbulb: The air dam does a great job at keeping air away from the front wheels and wheel well. Coupling his advice and expertise with the recent results of Daox's air dam, I decided to put it back on!



Still has the old duct tape residue on there!

The front had a problem with bending in over time, so I got pieces of aluminum bar and drilled them in behind the dam and in front of the bumper.



I was not satisfied, however. The tires seem to be too unprotected. The air dam was just too short for me and my aero crazy self! So I would like to present:

The Lawn Edging Body Kit!





Now, THAT is low enough! There is about an inch and a half of clearance around the outside. I did not have time to test it out though, but I am going on a long drive in the morning in which the route is one I know quite well. I will update what I find out. There should be a noticeable difference, with a majority of the air that would be affected by the tire is being diverted. Well, I'll know soon enough

I do plan on coastdown testing when I get my MX3 wheels and smooth covers put back on. I'm hoping to best a Prius's 0.26 Cd

[freebeard]

The interesting part of the tests will be driving it over a speed bump to see what happens.

[BabyDiesel]

I didn't get a chance to try out a speed bump yesterday. It hit only once in a 75 mile round trip, and that was because the road I was turning on was highly banked. No damage though, the aluminum bars are doing an excellent job at keeping the shape the same. I've had it up to 60 mph and it looks the same

[freebeard]

My intent was not to imply bad things would happen, just interesting things.

The first/last time the suspension work was done on my car I had to raise it to get over the speed bump right in front of my place. ...to 2 3/8ths inches, and it still wouldn't clear the tallest 10% without grinding. When it was re-done it came back a little higher, but still scrapes on at least one.

But that's solid metal; you lawn edging might well survive a speed bump. Since the flat part isn't as low as the curved part, will that help or hinder rebounding from the impact?

How many aluminum brackets and where? Three on each side behind the curve?

[dirtydave]

lawn edging can take a serious beating.

had 2" of clearance on my kia and we scraped on many speed bumps. it was horrible in the snow tho

[BabyDiesel]

Originally Posted by freebeard

My intent was not to imply bad things would happen, just interesting things.

Since the flat part isn't as low as the curved part, will that help or hinder rebounding from the impact?

How many aluminum brackets and where? Three on each side behind the curve?

Of course! I am yet to see a spark show from the air dam dragging

I'm unsure how the shape will affect rebounding. I t has done good so far. I have made contact 4 times since my last post from a random dip in my girlfriend's neighborhood. No damage at all, it looks the same.

IIRC, there are 6 aluminum brackets holding the front of the top piece in place. Where the second layer starts closest to the middle, there is 1 bracket to keep that edge from folding inward.

[JohnAh]

Originally Posted by BabyDiesel

I have many answers to the BSFC problem...

...BSFC is around 270 at cruise now (50% load at ~2000 rpm). Decreasing drag will only make that number go towards 295 from decreasing the load. No no, it is going up!

Quick answer, I have not read the thread beyond that point above:

A quick and easy compensation for dropping out of the BSFC sweet-spot is to practice "burn & glide" (also "pulse & glide" or "burn & coast") driving style. I drive my entirely stock Saab 96 from 1975 at around 4.7 L100 (60 mpg) with this method, as an average consisting of both highway and rush hour city traffic. I'd love to make some aeromods in the near future, but the WAF (wife acceptance factor) is quite low on such modifications.

B&G is definitely not a relaxed driving style. You have to work with your car in any traffic situation and road condition continously, but B&G combined with engine shut-off is what realy makes the difference! I start my engine as often as twice per minute! I have been waiting for my starter to wear out over a year now, but it resists my abuse...

A nice reward for the hard work of B&G is that your increased attention to the traffic improves safety. When you see every car in sight as a potential killer of your inertia, there will also be a reduced risk for them to kill YOU! By getting more observant, and better at planning your driving, you often get rewarded by a nice last laugh when you pass one of those hectic idiots for the third time in city traffic.

[JohnAh]

Burn & glide should offcourse be combined with DWB, driving without brakes. The basic concept is that using the throttle is no sin, in that your expensive fuel is traded for the forward motion you need. (B&G only makes that conversion more efficient) Every time you use your brakes (or engine braking) to reduce the speed is a failure! Any braking is a wasteful conversion of forward motion and intertia to heat. Regenerative breaking in electric vehicle will reduce the energy penalty, but always come with a loss in heat somewhere in the system.

Driving without brakes is the only 100% lossless way to keep speed down when needed! Check out the basics of speceflight, that's where the true ecodrivers are!