Honda Insight Tail Extension Project

[botsapper]

But now I work in a plant that makes aircraft components, even though we don't deal with aerodynamics. There's an awful lot of full-sized pickups in the parking lot, and a very large number of Prii. I think a boat-tail might go over just fine.

Interesting observation, similar vehicle demographics in Northrop Grumman, Boeing & defense manufs. parking lots. SUV/trucks for the assembly/mach. guys and Prius/hybrids for the tech/engineering guys...Porsches, Audis, BMWs for sales.

[SoobieOut]

The comment about drafting behind 18 wheelers reminds me of a family trip back in the 60's, when I was about 5 years old. We travelled from Maryland to Florida in a VW bug. Two adults, 2 children with several large suitcases tied to the roof rack. The stock 1958 VW bug had 36 HP and a top speed of 55-60 without the large windjammer on the roof.

So my dad would wait for a 18 wheeler to pass then try and get in his draft. Sometimes the truck was moving too fast and would lose us. Sometimes we would catch the free ride. This was very dangerous, but in the 60's few cars had seatbelts, and fewer people actually wore them.

[3-Wheeler]

Originally Posted by redyaris

You mit want to look at the craigvetter.com for some Ideas then you can look at what I have done under redyaris the bike is gray and you can look at what I have done so far. There are two other people on this website Janvos and the dutch guy on the ecomodder home page.

Yes, I've followed the many modifications that Craig Vetter has done to his Honda scooter over the last two years.

The dutch guy as you refer to him, is a beautiful piece of work, but limited in it's application when it comes to severe sides that we have from time to time. I have encountered 40 mph side winds years ago on my old Honda 500 with a full fairing and don't care to repeat that experience on only two wheels.

Jim.

[3-Wheeler]

Originally Posted by redyaris

How different is this form the responce before the boattail? Or is this the highest side winds you have encountered?

Your english is a little hard for me to understand, but 50 mph side winds is not something that one encounters here in Wisconsin on a regular basis.

Jim.

[Weather Spotter]

any MPG improvement data? I want an idea of what to expect if I make one

[3-Wheeler]

Originally Posted by Varn

....Perhaps a vertical tail fin is needed to give the back of your car some sail area to help keep the nose going straight in a side wind.

You may also have improved the lift of your vehicle in that the weight is being removed from the road decreasing your traction and control.

I understand the reason for noting the use of a rear fin, but I would not want to be the one to try it!

Why?

It would add a tremendous increase in the side load to the foam/fiberglass composite and could overload the structure in high sidewinds. No sir, I can live with the handling of the car just fine as it is!

As for lift, take a close look at the sharp seams, both on the top edge and bottom. These ridges are designed to stop the creation of lift in sideways winds because the hope is, this sharp transition is abrupt enough to cause massive flow separation and no lift!! This is by design.

The idea came from BicycleBob during several email exchanges (several years ago) before the tail extension was even designed.

Jim.

[3-Wheeler]

Originally Posted by endurance

Sounds like a matter of leverage. You put a longer lever behind the rear wheels, which act like a pivot.... By adding the extension, you just gave it more leverage.

This may be true, but if the leverage were higher, the car should align itself more into the wind direction because of the rearward shift of "center of pressure". I did not notice this during the wind storm. The wind continued to push the front of the car in the opposite direction, so the longer tail offered minimal leverage to the wind.

Originally Posted by endurance

Probably a rare problem unless you live in Wyoming, but good information to have going forward. It makes one ponder the benefits of having a removable system for days like this.

Removing the tail would not be practical for me, since I would then have to store it somewhere and then drive home with no tail lights.

Jim.

[3-Wheeler]

Originally Posted by RobertSmalls

I'd like a car where the entire body yaws to point directly into the relative wind. The driver's seat and controls would not yaw with the body. This would allow you to retain the benefit of streamlining despite a crosswind.

Robert,

You could add that to YOUR completed project!

Jim.

[3-Wheeler]

Originally Posted by MetroMPG

Jim: earlier in the thread you mentioned posting a summary/breakdown of the project (costs, etc.). Have I missed that?

Hi Metro,

No you haven't missed it. I've been on the road for work lately and have had a short amount of time to devote to compiling a summary page.

Originally Posted by MetroMPG

Curious: where do you work - or what kind of work, if you don't want to be specific. I can think of workplaces I've had that would have been aeromod-friendly, and others that would have been, um, aeromod-averse.

My work has absolutely nothing to do with car efficiencies and/or aero-dynamics, and I mean that in a positive way.

I simply got very interested in the cost of gas, the environment, and national security when our dependence on foreign oil came to a head in the spring of 2007 with the price of gas approaching $4.00 per gallon.

The light bulb turned on for me, and has continued burning brightly since. I started hyper-milling and got real interested in aero body shapes when BicycleBob got me in touch with EcoModder. I found Bob on another site and we started corresponding over another design that I was interested in at the time.

Originally Posted by MetroMPG

One other question: will the tail live on the car during this winter?

You bet! I have full intentions of making all of my designs work throughout the year, and under normal driving situations that everyone else encounters.

Jim.

[3-Wheeler]

Originally Posted by RobertSmalls

That's a very interesting point.

I hesitated to add a boat tail in part because I thought it would be frowned on. But now I work in a plant that makes aircraft components, even though we don't deal with aerodynamics. There's an awful lot of full-sized pickups in the parking lot, and a very large number of Prii. I think a boat-tail might go over just fine.

Most people seem fairly passive about the tail and don't seem to care either way.

We are having some work done in our office area by general contractors and one of them asked how much more fuel mileage I was getting. In otherwords, he could tell just by the shape that aero efficiency was the goal, but had no idea that the car can get close to or over 100 mpg. Most people guess about 50 or so for some reason.

I'm hoping the tail will get more people thinking that aero is cool!! It helps everyone out in the long run.

Robert, go for it! And contact me when you want to discuss working with foam more. We're all on this planet for one reason or another, and mine seems to be helping with foam of all things.

Jim.