Honda Insight Tail Extension Project

[Varn]

3 wheeler,
Your list of parts is interesting. It takes a lot of vision, trial and error, much more than a list, no matter how detailed.

Have you worked on the reasons and solution to your instability in the wind?

[3-Wheeler]

Originally Posted by Varn

....Have you worked on the reasons and solution to your instability in the wind?

Hi Varn,

I don't recall using the word "instability" in any of my descriptions on how the car handled the large side-winds.

The phenomena I recall was that the front end still pushed during the high winds and I had to correct for this with the steering wheel, by turning back into the wind. I also mentioned that the handling during this event was similar to what the car felt like without the tail.

So the addition of the tail did not really alter the handling in an adverse way, which is really good news.

Jim.

[redyaris]

3-wheeler
Thanks for this thread, I am thinking about a similar project for my 2007 Toyota Yaris hatchback. The project will start as a Kammback with the provision of mounting points for an extension to form a boat tail.

[fusion210]

Your tail looks most excellent! Any more pics? I noticed the pic in your av and couldn't help but wonder what other ones you have of it out in the open.

[Varn]

Guess I read more into your statement during the wind storm than was there.

Originally Posted by 3-Wheeler

Hi Varn,

I don't recall using the word "instability" in any of my descriptions on how the car handled the large side-winds.

The phenomena I recall was that the front end still pushed during the high winds and I had to correct for this with the steering wheel, by turning back into the wind. I also mentioned that the handling during this event was similar to what the car felt like without the tail.

So the addition of the tail did not really alter the handling in an adverse way, which is really good news.

Jim.

[3-Wheeler]

Originally Posted by Varn

Guess I read more into your statement during the wind storm than was there.

Hi Varn,

Well, I was anticipating that the extra length to the car would move the center-of-pressure more rearward, and cause more neutral steering in large side-winds instead of pushing the front end.

When this did not happen, at first I thought something was wrong-with-the-picture, but then realized that I would rather have the steering more "normal" than have the wind control the back end of the car and possibly over correct the steering inputs.

So overall, I am very glad the steering control remains the same as before.

Jim.

[MetroMPG]

Originally Posted by aerohead

... a fella drove up in a 1st-gen Insight.... and he said that coming home,he drafted 18-wheelers ... pulled 95 mpg at the posted speed limit.

A bit off-topic, but a 1st gen Insight owner told me he also got numbers close to that with very close drafting at 100 km/h (62 mph) on the freeway...

... at least up to the point where he was pulled over by the police and ticketed for tailgating. (And rightly so!)

The cop told him he thought at first the Insight was being towed by the other car.

[MetroMPG]

Originally Posted by 3-Wheeler

I would have to say that so far, a 10% gain seems fair, but Metro's was closer to 15%, and both our cars are similar in aerodynamics overall.

I suspect that my car may have had more to gain, percent-wise, than your Insight:

The main difference being the cross sectional area at the rear where each of our OEM shapes end and where the tails begin (or began in the case of my prototype tail, which has long since gone out with the recycling). I suspect the area at the rear of my car is bigger - thus more room for improvement.

I'd be willing to calculate/estimate that rear area of my car if you're interested in comparing. I bet this has probably come up already.

Darin

[COcyclist]

Originally Posted by fusion210

Your tail looks most excellent! Any more pics? I noticed the pic in your av and couldn't help but wonder what other ones you have of it out in the open.

Maybe the tail is not finished enough for unveiling? But you must have protected it with something so the winter rain and snow doesn't melt the spackeling, right? Do tell.

Also, I am hoping to see some more photos of your LED tail light array in action. It looks like you used a slew of bulbs instead of just replacing the factory ones like I did. Yours should be much brighter than stock. Amazing craftsmanship, by the way.

[3-Wheeler]

Originally Posted by MetroMPG

I suspect that my car may have had more to gain, percent-wise, than your Insight:

The main difference being the cross sectional area at the rear where each of our OEM shapes end and where the tails begin (or began in the case of my prototype tail, which has long since gone out with the recycling). I suspect the area at the rear of my car is bigger - thus more room for improvement.

I'd be willing to calculate/estimate that rear area of my car if you're interested in comparing. I bet this has probably come up already.

Darin

Hi Darin,

I think you will prove to be most correct in your assessment!

Besides the ongoing coast down tests, I have two tanks of gas that say the increase in efficiency due to the tail is small for the Insight. Of course we can always take this with a grain of salt, as the ambient conditions are not the same now as they were last spring, when I stopped driving the car, but check the figures during the same months last year, and there is a slight increase, but not 10%.

About the only way I can think of to really get an idea, is to stay late some night after work where we have a small garage that the tail can be bolted/unbolted and checked on a 55 mph stretch of road that is normally busy during the day, but may quiet down enough at night and very close to work.

There is only the Interstate that is really flat near my house, but is always very busy, so this option is out.

There is one other 55 mph country road that I normally drive, but it is old and very bumpy, plus being 20 miles from the house, makes it hard to drive home to swap the tail on/off.

I think a definitive A-B-A test is in order when time permits; maybe in a couple of weeks on a Friday night.

Jim.