Boattail the most aerodynamic car... an Insight

[jamesqf]

It really shouldn't be that difficult to do a boattail for the Insight. The curved part of the rear end is just one moulded plastic piece that is easily removed, leaving a flat bulkhead. (And the rectangular aluminium bumper that's normally covered.) Mount a block of foam to this surface, perhaps with a couple of brackets or whatever for strength, carve it to shape, and cover it with a light skin. If done with a bit of care, it could easily be swapped with the original moulding for A/B testing...

(I own an Insight, and thanks to having been rear-ended got to see under the skin...)

[MetroMPG]

Originally Posted by jimepting

Taking on the disadvantages of movable fairings for potentially small improvement doesn't seem very practical.

Nowhere in the EcoModder user agreement does it say we must only pursue/discuss practical modifications.

[aerohead]

Originally Posted by jimepting

The Honda Dream 2 is a motorcycle, so that doesn't seem a particularly applicable comparison. It may have a Cd of 0.10 by itself but with an upright rider that seems doubtful. The GM Sunraycer is a pure teardrop PV research car, far less practical than an Insight for everyday use. I like modding as much as the next guy -did a lot of it on an Echo. But from my viewpoint, whatever is done must be practical from an everyday use viewpoint and cannot permantently damage my valuable car. So, I suppose my objectives are a bit different from those interested in pure research.

Still, I'm an engineer and would love to have a workspace to build an Insight tail for testing purposes. I think an attractive and practical Kamm back extension could be built using this technology:

Using Fiberglass/Foam Sandwich Composite

Front wheel fairings would seem attractive, but if one carefully studies the details of what Honda has already done, improvements may be only slight. Wheels which are already pretty smooth, front wheel stakes, aerodynamically shaped openings at wheel rear. Taking on the disadvantages of movable fairings for potentially small improvement doesn't seem very practical.

The Honda Dream 2 is a 3-wheeled solar race car based on the GM/AeroVironment Sunraycer,which demonstrates an actual vehicle of sub-Cd 0.10.------------------------As the popularity of dead soldiers,Marines,airmen,special-forces personnel,contractors,etc.,has passed from vogue now,some are looking at un-practical solutions to separate the western developed nations from Mesopotamian petroleum and the danger it poses for those reliant upon it.--------------- Un-practical,low-Cd vehicles are a natural candidate for weening oneself from this Middle-East teat.---------------------- The Insight is one of the best candidates among the stable for streamlining,as it has demonstrated the highest mpg of any car ever offered for sale and is already configured for the boat tail,the only modification which can produce significant drag reduction.----------- I'm not lost to "length" issues,which is why I am personally leaning towards a trailer unit as a "practical" solution.In this context,movable gap-fillers constitute a 20% drag reduction and 10% mpg improvement alone,and practical or not,will remain on the plate.

[jime57]

The first full page of Google results for the Honda Dream 2 were for a motorcycle. I guess there might be a PV race car somewhere in the other pages. I'll take your word for it

We really don't disagree all that much, otherwise I wouldn't have bought the Insight in the first place. I'd love to have a workspace to try some of the things you mention, those that wouldn't permanently damage the car.

[aerohead]

Originally Posted by jimepting

The first full page of Google results for the Honda Dream 2 were for a motorcycle. I guess there might be a PV race car somewhere in the other pages. I'll take your word for it

We really don't disagree all that much, otherwise I wouldn't have bought the Insight in the first place. I'd love to have a workspace to try some of the things you mention, those that wouldn't permanently damage the car.

We've kicked around the idea of using some of the "soft-touch" bicycle racks as Thule and others manufacture,as a foundation for mods.These systems are so good,they provide a sturdy base without the need to "penetrate" the vehicle's sheetmetal or plastic fascias.------------ Something like that might allow you to affix a lightweight shell to the car with no risk to the finish.--------- It's possible to mock-up a prototype completely with cardboard and 2-inch masking tape.A coat of polyester resin followed by wet layups of fiberglass cloth/mat/cloth can produce a very durable structure.-------------- If you don't have space at home,you might find a shop which would allow you to use a little floor space for a project.----------- I covered the floor of my apartment in Dallas with 8-mil poly sheet and pulled off all kinds of projects when I lived there.Got all my deposit back too! Creativity will open doors.

[basslover911]

Originally Posted by jamesqf

(I own an Insight, and thanks to having been rear-ended got to see under the skin...)

Any pics by any chance?

[winkosmosis]

Why not keep the stock wheels? They're already aerodynamic and light alloy. You'd have to replace them with heavier steel wheels.

[alohaspirit]

maybe a large foam/inflatable boattails like craigvetter

ive seen the rear bumper support and it really is puny