why hasnt someone made the inflatable boat tail yet?
 

hi

ive not been posting for a year because i didn't have a car. now that i'm back i feel a little disapointed that no commercially available retro-fits are available for either the inflatable boat tail or the hybrid retro fit.

how difficult would it be for us to go on dragons den or american inventor and propose this idea?

How much time/money do you have? That will be a big factor.

inflatable
 

I looked into it in the 1980s and determined that scope of it was beyond me.Here's a short list of the challenge:
1 Without standard,rationalized car design,one must engineer a unit for every vehicle.
2 That requires that you re-invent the wheel for every vehicle out there.
3 This requires an inordinate amount of capital.
4 Venture capitalists want patent protection before they'll risk their money.
5 Patents are very expensive,and are no protection against infringement unless you have $250,000 set aside ( cash) for each case,to prosecute.
6 The trials can take years.
7 Since you're attempting to create a market for something that has never existed,you have no guarantee that even if you produce the product,that anyone will purchase it.
8 If the 'market' doesn't purchase the product, you default on your leveraged operation,you file for bankruptcy,and disappear from the marketplace.

Many a soul has taken out a second mortgage to finance their dream,gambling the security of themselves and their family against an uncertain future.80% fail within the 1st three years.
To be pragmatic,if you want an inflatable unit for your vehicle,I suspect that you'll be left to your own devices.
Nobody is going to risk their future on you.
That said,if you approach a would-be entrepreneur with enough cold cash to make it worth their while,I'm sure they'll be happy to jump into production.Or do like Santo Island,Denmark,and simply get all your neighbors to go in on a CO-OP to produce for yourselves first,then after you're all satisfied,begin selling to the outside world having already recovered your full investment and retire on the income generated.

It may be possible to engineer a kit that adjusts for a wide range of cars, but that is yet another challenge. One needs either internal ribbing to keep the top flat, or an arrangement with stringers inflated to high pressure. It could probably use a standard rear panel with trailer light hook-ups. That might be carried on a lazy-tongs frame, so it could be retracted neatly and then help contain the deflated tail. This all has to be done with good rear vision, and a fashionable look, if you want more than a few sales.

How about start some market research here with a thread/poll of how much people would spend on an inflatable boat tail? Would be interesting.

If it increases FE 15% It might pay for itself quickly. Working backwards from the results you could figure out the production cost target you would need to be profitable.

We have not seen anything close to a slick, professional-looking inflatable tail extension even as a prototype yet. Do we want to ask about the demand for a reasonable attempt at the wish-list, or the demand for something that wives would only veto because they look Too sexy?
This may not be the best place for market research - we are just as bad as companies for wanting to invent our own stuff, methinks. :-)

Fkfs
 

Has everyone seen the 'extensible' inflated boat tail from 1936 FKFS that Fachsenfeld et al developed? It's featured in Hucho's book and is the sweetest I've ever seen.
Hucho suggest up to a 35% drag reduction,which would be a 17.5% mpg at 55-mph,more at higher speed.
Goodyear Aerospace has the fabric.Inflatable advertising manufacturers.

I remember seeing a newsreel (very old from the 40's) about an inflatable plane made by goodyear. When deflated it could fit in a crate, the engine and prop were the only solid devices. When inflated it looked very solid, and had an onboard pump to stay inflated. Seems like this is very doable, maybe Goodyear could get onboard with this new idea. If it could save you 20% on fuel, it would pay for itself.

I've been thinking about this for a while too. However, I plan on making it for cargo trailers where the back is completely flat and vertical and the improved aerodynamics would be most drastic. Any ideas on what materials would work best for testing, prototyping?

Perhaps the best place to start would be a Van. Can't imagine a much worse tail so the mod would stand a great chance of significantly improving aero.

Just need someone who makes those inflating jumping houses to get interested. Considering all the intricate stuff they put on them these days I'm sure they could do it. They likely also have a van.

Exhaust from a V8 could inflate it and intake vacuum could deflate it.