DIY hitch-mounted boat tail on Audi A2 3L (photos)

[MetroMPG]

Found out about this Audi + tail from an inbound link to my thread about the Blackfly's prototype boat tail.

An Audi A2 forum was reacting to this vehicle:



Did a Google search of the text on the side of the tail, which led me to a Netherlands web site documenting the build: aerotail

EDIT: the tail builder has joined EcoModder and posted a thread here: http://ecomodder.com/forum/showthrea...2-18413-2.html







More photos & info (you'll have to Google Translate it, unless you read Dutch) here:

aerotail

[MetroMPG]

I like their analysis:

+ 50% boot

- 10% fuel

and general description (Google translation):

This tip is mounted on a pivoting, extended bike rack on our Audi A2 3L.

We looked for a way to get some more baggage to be taken without compromising speed or fuel consumption. With a trailer you can not ride as hard longer. And luggage on the roof creates more drag and thus more fuel.

With this car we drive fairly economical (average 1:30 on diesel). Now we have fuel economy by reducing wind resistance point behind the car.

[Tango Charlie]

Wow, I really like this. It looks decent. The build quality is quite good.
You hear that?...
It's the sound of gears turning.

Hmmm.

I could so DO THIS.

I have the need (Trips out west in my future). I have the skills. I have the tools. I don't have the materials, but that can easily be remedied.

I should do this. I must.

[MetroMPG]

Looking forward to the build thread.

[Angmaar]

It's surprising to see people bash something that gets better fuel efficiency. I guess i'm too used to ecomodder.

[thatguitarguy]

Well, that looks a lot smarter than a car-top box - and smart is pretty in my book.

If it were built and marketed as storage enhancement first, and aero/economy enhancement second, it might be more acceptable to the naysayers.

Looks like it could use some better gap management, but I like it. A lot.

[lunarhighway]

considdering the A2 already has an 0.25Cd ! one can only imagine what the Cd of this combination must be. plus the fact this is esentially a cargo box makes it legal where permanent extentions would not be

[Piwoslaw]

Metro, THANK YOU for the link This is the kick in the ar$e I need to get my mods going again (and legalizing, see below).

Have you contacted the owner? I'd like to see a few more construction details covered, maybe in a new thread? If you like, I can write them a message since I'm interested in how to legalize this in Europe (the license plates suggest it is legal).

I followed a link and noticed a page about an aero'ed e-motorcycle, which I thought I'd seen before (EM?):
e-motion

That A2 forum is hilarious
But should I be laughing at them when they are already laughing at us? Feedback loop, feedback loop, feedback loop, ...

Originally Posted by Tango Charlie

I could so DO THIS.

I have the need (Trips out west in my future). I have the skills. I have the tools. I don't have the materials, but that can easily be remedied.

I should do this. I must.

Same here, only...
I have the need (car used mostly for long trips with friends). I can find the materials and tools. I only partially have the skills, but I'd be more than happy to remedy that

Originally Posted by lunarhighway

considdering the A2 already has an 0.25Cd ! one can only imagine what the Cd of this combination must be. plus the fact this is esentially a cargo box makes it legal where permanent extentions would not be

And here is my problem: making it legal. Polish parliament has been too lazy to pass laws allowing the use of rear-mounted cargo carriers, so it is illegal here to mount anything that covers the registration plates, and it's also illegal to take your plates off and transfer them to the bikerack/cargo carrier, even if it was designed for it (and legal in other European countries). Go figure
Gotta find a way around that.

[lunarhighway]

And here is my problem: making it legal. Polish parliament has been too lazy to pass laws allowing the use of rear-mounted cargo carriers, so it is illegal here to mount anything that covers the registration plates, and it's also illegal to take your plates off and transfer them to the bikerack/cargo carrier, even if it was designed for it (and legal in other European countries). Go figure
Gotta find a way around that.

what about laws regarding trailers? i'm sure they must have some regulations for them (and perhaps the fewer the better).

what i'm thinking is if you add two wheels to the tail and perhaps some other things to place it in the legal definition of a trailer, (without being one)
if you'd ever get into some legal trouble because of the contraption, and you can prove it's legally a trailer, they can't do much. bit of a silly idea perhaps, but if lawmakers fail to be creative you must

[skyl4rk]

I have been planning to build a similar cargo box, delayed by a boatbuilding project. I really want the extra 10% FE. If I build a cargo box and add a killswitch, I think I could get 20% by EOC as much as possible. With my car, I think I could reach 60 mpg. For a while I was thinking about selling my car and going without a car, but I really enjoy driving through the country and seeing the sights so I think I will do what I can to increase FE. I like it that I could get better mpg than a lot of motorcycles out there.

There are two methods that I have been thinking about:
1. Plywood stitch and glue - this is a boatbuilding technique using epoxy and thin plywood. I would use the thinnest, lightest plywood I can get from Menards. This would result in a squared off cargo box.
2. Insulating foam - find an adhesive that will glue foam (PL Concrete and Masonry Sealer?). Get sheets of insulating foam and cut them to shape. Use screws to screw and glue the sheets together. Do some minor shaping with an orbital sander.

The frame of the cargo box would be a simple "T" of 1-1/4" steel square tube. I already have one made up. Then bolt on a piece of 3/8" plywood as a base, and the rest of the cargo box is fastened to the base.

I may build one to open up and actually use for cargo but I don't want any weight that far back so I don't expect to use it for cargo. I rarely fill my trunk, I have more space than I need. If I need to haul something big, I use a bigger vehicle. It is probably easier to just build a box that doesn't open.

Because of the reaction I got from my previous tail, I would label the thing "CARGO" with large letters. Even if it did not open up to hold cargo. just to minimize the hassles of rubberneckers.

I would add handles on top and skids on the bottom to make it easier to install and remove. Even if this reduces aero a bit, it will make it much easier to deal with.