Aero Metro by JoshuaChance 001

[joshuachance]

Last year I purchased a 1995 Suzuki Swift for $450. Great little car, but pretty much a piece of junk as far as looks go.

No worries, for me though, I was driving 60 miles a day round trip to work and back, and the big ol' suburban I had at the time was getting 12 MPG. The new Swift (basically Geo Metro) got me a great 40 MPG instead.

Horray for not spending all the money I was making at work on just getting to work... Never endless battle...

So, last year, I decided to play around with a little aerodynamics!

I added a new, long tail to the back of my little car. Built out of all the free stuff I could find... An old 6 foot ladder was the main support. A bunch of 1x3 lumber I had around, a little duct tape, and all the free cardboard I wanted from work.

Putting all this stuff together, I came up with a boat tail that stuck out the back 5 feet farther than the original bumper did...

Before addding the boat tail, I got a rather consistent 40 MPG with my 1.3 liter (4 cylinder) car, for at least 5 full tanks. After the tail was complete, I was up to 48 MPG at the best!

Score! I had proof of concept! The idea worked...

Here in Oregon, it rains 11 months a year. So, my little project was rather short lived. After about 2 months and maybe 8 tanks of gas, the rain got bad enough to basically melt a bunch of the cardboard off. Ooopps.

Taking off the cardboard and lots of wood I used for structure, I know it weighed over 100 lbs... Probably closer to 150 or 175 lbs...

But for being so simple and cheap, fact is, that the boat tail did save me fuel and money.

So, now it is summer in 2011, and I am ready to try again... With lighter and longer lasting materials! Very cool, very fun!

There will be pics soon, if I can get them on here, and updates as often as I can manage.

My overall intentions are to provide examples of the simplicity and cheap budget that aerodynamic modifications can be done at. It may not be appropriate for every person to spend increadibly much modding their vehicle...

It would be great, however, if anyone could do these things inexpensively and achieve a true benefit from doing so!

Hope you enjoy and are able to use any of the information I can provide...

Thanks,
JoshuaChance

[Piwoslaw]

Wow! Others have seen a 15%-20% improvement with a much smaller weight penalty, but each case is different. Please give us more info and some pictures!

What about other aeromods - grille block, wheel skirts, bellypan?

[euromodder]

Welcome to ecomodder.

Originally Posted by joshuachance

Last year I purchased a 1995 Suzuki Swift for $450.

Which version did you get ?
1.0 L or 1.3L, maybe even the sacred XFi version ?

So, last year, I decided to play around with a little aerodynamics!

If you want spred and great MPG, that's the way to go.

Taking off the cardboard and lots of wood I used for structure, I know it weighed over 100 lbs... Probably closer to 150 or 175 lbs...

That's a sizable increase for the tiny Metro.
It won't matter as much @ constant speed on the motorway, but it will hurt in stop & go town traffic.

There will be pics soon, if I can get them on here, and updates as often as I can manage.

You'll need a few more posts (5 or 10) in order to be allowed to put up pics & links.
If you split your answers a bit, you'll get there quickly

You might be able to create a personal album already (in your user control panel) but I'm not sure about that.

My overall intentions are to provide examples of the simplicity and cheap budget that aerodynamic modifications can be done at. It may not be appropriate for every person to spend increadibly much modding their vehicle...

Look at Weather Spotter 's Matrix boattail.
It isn't the prettiest but it does the job.
For a prettier one, look at 3-Wheeler's Insight boattail.

[some_other_dave]

Come November, you can usually pick up coro-plast (corrugated plastic) election signs for very cheap. Actually, for free after the elections are over! It's a bit late for your uses this year, but you could be gathering material for the next season.

-soD

[joshuachance]

Excellent! Thanks for all the replys everyone!

It is great to see such an extensive online community interested in the same things I am... I'm sure I will get a lot of help and see some good constructive criticism.

I will break these posts up a little, since I am new here, in hopes to get some pics up soon. This thread is for my 2010 project wich I have a few pics of, and later I will start one for my 2011 project wich is currently under way...

Ok, time for work now, but definately more to come soon!

Thanks again
JoshuaChance

[joshuachance]

Hey hey...

(OK, can't 'quote' text from my phone I guess)

So, I will start off with the first message from piwoslaw...

----------------------------
"Wow! Others have seen 15% - 20 improvement with much smaller weight penalties, but each case is different. Please give us more information and pictures!

What about other aeromods? Grille block, wheel skirts, belly pan?"
----------------------------

Yes! Very good point... 2010 was the first year I really thought this would be a great experiment. I know that the materials I used were heavy. But what I was really aiming for was 'proof of concept'. I wanted to see for myself if there was any real proof that a freeking giant tail off the back of my car could help my fuel mileage. Well.... I think for myself, I totally proved it worked!

Of course every case is different. That's why every single person will learn their own little things about aeromodding (that they will hopefully share here). For instance, I learned that cardboard is fairly heavy compared to other materials you could buy, and also (baing in rainy Oregon), that cardboard will pretty much just MELT off the car when it gets really wet..... Ha ha ha. Shoulda seen that coming.

This year, i've improved with an all aluminum structure, and skin materials which are not water soluble.

About other aeromods...
I had considered the tail to be the largest mod, so I put it as 'phase 1' in my objective. Too bad it was so short lived. My plans after that were; Phase 2: A front air dam about 1 1/2 foot extended out from the front bumper. Phase 3: A belly pan and possible muffler mod. Phase 4: wheel skirts, rear wheel aero-covers, and possibly new harder tires with less rolling resistance.

So, thank you very much for the questions... of course these are all just ideas running around in my head until I can spend a little time getting my hands dirty! (That really is the most fun part).

More to come my fellow modders!

Thanks,
JoshuaChance

[joshuachance]

Here is one of my first drawings from quite a while ago... you can see my original basic concept was indeed VERY basic.

[joshuachance]

A few more preliminary sketches...

I found it was easieast to download a simple black and white photo of the stock car... then draw on that for angles and contours and whatnot.

[joshuachance]

And, one last picture for the day...

This is the finished prototype from 2010.

You can see all the thick cardboard and massive duct tape job I put into the tail. Most of the reason it weighed so much.

Hope everyone enjoys these. Let me know what ya think!

Thanks,
JoshuaChance

[ChazInMT]

Hey Joshua, Here's a quick dealy showing your car with the aero template. As you can see, the ideal would be very long. However, when you shorten the boat tail, as you did originally, and appear to want to do again, you pay a penalty. I think you'd be better off staying closer to the ideal curve here and just "Squaring off" the back. I'm sure others will chime in. Great job so far!




I have even cheated the template forward and smaller than it should be, I don't think you'd pay much of a penalty for following the line on my cheat, but if you get much below it, it will not be as ideal. Also pay attention to the transition area, keep it a gradual change, try not to let the air know what you're doing to it.

Here's a cropped pic where it seems practical to end your long Kamm. This would net you around a 40% total ideal, which would improve you from the 15% you're at now, leading to a 40% drag reduction, give er take. YMMV.



I'd only think about messing with the front of your car after you have the back made to your liking, front mods won't return near as much as rear. Of course I'm talking about big front changes, grill blocks and air dams obviously have big returns on investment due to their cheap cost in time & materials usually.