Tower 2 results

Tower 2 weighed 4.905 lbs and withstood 19,867 lbs of force before it succumbed to the pressure. This results in a strength to weight ratio of 4,050.36 lbs/lb. It was the heaviest tower and withstood the most force of all the towers tested however it did not have the highest strength to weight ratio, but it was the second highest.

Finishing touches on tower 2

It just didn't look like a tower...

Balsa wood tower 2

Second design with some (hopefully) improvements. Built with high density balsa wood it has much more bracing, but also much more weight so we'll have to wait for the test to see if the compromises pay off. Bathroom scale weight is 4.8 lbs so it needs to take 17,150 lbs of force to better the first design.

More pictures

More pictures of the balsa wood tower project at my yahoo group.
http://groups.yahoo.com/group/ROBERTWB70/photos/album/1171334026/pic/list

The tools I used on the Balsa tower

Here are a few pictures of things I used to build the tower. Not pictured is the table saw I used to rip the 1/2" x 3" x 36" wood down to 1/2" x 1/2" strips, this would have been completely unnecessary if I could have found enough of the right size pieces.


A simple/ cheap plastic miter box and saw for accurate cuts , square to check assembly, and a sanding block to fine tune lengths and angles as needed. This is all stuff I had and rarely ever gets used but it all came in handy for this project (not completely true since I use the square on almost every project I do).


Plenty of clamps, I hardly ever use these things but they turned out to be perfect for this project.


I feel this is the best wood glue for any woodworking project and I don't think it's ever let me down. It's fairly cheap, easy to work with, water clean up and can be un-clamped after 30 minutes drying time.

Tower Test

The tower was tested to failure today, it weighed 2.165 pounds, and withstood a peak of 7,735 pounds of force for a strength to weight ratio of 3,572.75 lbs/lb. Here are some pictures of the aftermath.

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School project

In my structural analysis class we have to build a 3 foot tall balsa wood tower that will be tested to failure. No matter how many clamps you have you always need more...

MPG graph

From the FE tracking tool at the best FE forum on the web.

Fill up day

10/08/2009
343.2 miles
7.586 gallons
$2.379 per gallon - $18.05 total
45.24 miles per gallon
19 miles per dollar
5.26 cents per mile

Battle scars

Bent one of my future mounting points for the side skirts yesterday, actually this is the second time I've bent it (much worse the first time but no pics). I had a tire and wheel and a passenger in the car otherwise it wouldn't have been a problem but I'm going to shorten them to prevent future problems when I get a chance.

Rear fascia / bumper cover

After some research it turns out the optimum angle for airflow coming out from under the rear of a car is around 3 degrees so I decided to put the section I cut off back on. Here you can see the frankenstein like results.

Temporary cardboard partial Kammback

I have been planning the permanent version for a while but I decided to do this temporary extension to see how it effects rear visibility. It only took about 30 minutes to make and it didn't look too bad when I first did it, next day there came a torrential downpour and I had to do some repairs to it so it's not quite as pretty now. I'm hoping to keep it on at least one full tank to see how much it improves FE. Since I've had it on a few days I think I will make the permanent version longer and incorporate a clear section in the center for visability, haven't decided on how to attach at the edges yet but I'm thinking either sheet metal or fiberglass to form the curved part while the center flat section will be lexan os something like that.

5 minutes later- RED wheel skirts

Rear wheel skirts mostly done

They still need a few finishing touches but they are at least functional. Wheel spats will be made and attached to the piece you see hanging down in front of the tire. I really wanted the skirts to extend all the way to the bottom of the part where the spats will be but it just turned out to be to complicated for now.

Curvature intersection method

A couple of pictures showing one method of to help determine how to cut a panel to match up with the complex curves on the side of a car. This is basically the intersection of a plane and the side of the car so as to minimize the bending of the applied panel. I used a cheap Black and Decker laser gimmick that projects a laser line as shown in the pictures.




I had already done the front by the time I thought about this and it won't work there now so I projected behind the front wheel well (same curvature) to see if it looked like what I already did, looks pretty close to me.

Kammback angle?

I'm in the planning stages for a kammback extension and this is to help visualize the angle and length. It will block much of the rear view so I plan on making at least the center portion from lexan or polycarbonate.

Beginning of rear wheel skirts

This is the start of my rear wheel skirts, this part is permanently attached to the car and does not get in the way when removing the tires. There will be a lower part that attaches to fully smooth the airflow over the rear wheel wells. These are made out of 18 ga. galvanized sheet metal and riveted to the car body.

Front tire deflectors

For some reason on this car the front tires aren't entirely behind the front fascia so I made some extensions. This increases the frontal area slightly but it keeps the airflow cleaner so the net effect should be positive.


Front view-no more tire peaking out into the airflow.


Rear view

Side view


Overall front view.

Rear dress up panels

Panels to beautify the newly exposed spare tire well, might even have some very small aero effect but not enough to amount to anything.

In progress

I did some more work to the Geo today but it got dark before I thought about pictures. I made some fairings to keep the front tires out of the airflow as well as some panels to make the newly exposed rear look a little better. I also started on the rear wheel well skirts, got the top part done but I'm still deciding how I want to do the bottoms so they are easily removable for servicing.

I'm thinking about adding a Kammback and maybe some wiper deflectors into the mix too. And eventually I'll go fully smooth on the wheel covers but for now the ones I have are pretty smooth so not a big priority.

I've been getting 42 MPG for the last several tanks so I'm really curious to see what all these changes can do. As far as I can tell I'm already doing pretty good for an automatic trans car but this stuff is fun, much more fun than engine or paint and body work.

The back aeromod

I noticed a big chunk of the rear fascia hung down lower than anything else at the rear of the car so I decided to remove the factory air brake. I'll make some sheet metal covers to dress it up a little so it doesn't look quite so bad.
That separate piece in the first pic is what I cut off.

Front aeromods

The front end so far.
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Front air dam, partial grill block and filled hood/ bumper gap. I anticipate some good mileage gains from these modifications.


All the parts added this far are metal, mostly some old 5V tin roofing I had laying around from another project. There are a few pieces of 18 ga. galvanized but not much because it's harder to work with and complete overkill for these kind of modifications. Lots of pop rivets and a few screws holding it all together.


A hinged section I made in the center of the air dam because I like to be able to jack the front of the car up in the middle and my jack won't fit under the new addition.


Here you can see the jack just fits in the opening, there is a neo magnet on each side to keep the door closed. The magnets are mostly just there for cosmetic reasons so the door doesn't show when the car is sitting still, I'm sure air pressure would keep it closed at speed.

Still gotta do something to get those front tires out of the air stream.