Aero Trailer? Could it help FE?

[The Atomic Ass]

Originally Posted by bbjsw10

I was just thinking the motorcycle rims/tires would not add much RR.

Careful with that... Most motorcycle tires are NOT LRR. Grippy sport bike tires aside, most bike tires are made to GRIP. The RR of my scooter tires is something stupidly high, worse I think than offroading tires for trucks, and they're considered an LRR tire.

[bbjsw10]

Atomic Ass, would this because alot of the time you are on the side of the tire. Would it be the same about RR even when always 90deg. to the road? I was thinking smaller contact patch/lighter weight the better.

[wagonman76]

If it is light enough, how about bicycle tires? Theyre made to hold the weight of people, big or small, and take off-road abuse, most of which youll never encounter on-road. And if you really screw one up its super cheap to just scavenge another rim and buy a new tube.

[aerohead]

It would be really helpful to see the scale of your trailer in relation to the Metro,as Cd posted with his "Flea" integrated trailer (which by the way looks pretty damn good to me!).---------------------

And also looking at Cd's image,consider complete,movable gap-fillers to close the void between car and trailer.I never got to do this with the 2-wheel trailer at all,and with the 1-wheel trailer,I had only enough time to cobble up a panel for the top.-----------------------------

With respect to weight,my 2-wheeler and cargo added 1,300-lbs to the CRX and mpg dropped from 52,to 50-mpg.There was also no "bottom" on the 2-wheeler,so I suspect I lost some mpg potential there also.------------------------------------

With the 1-wheeler,I ran it virtually empty.At around 250-lbs and no side or bottom gap-fillers,I pulled 48-mpg across Texas,New Mexico,and Colorado,at speeds up to 80-mph and mountain passes as high as 10,600-ft ( Vail Pass ).Note: unbeknownst to me,I had two carburetor hoses completely burned through and engine ran rich ( you can see the black soot from the tailpipe on the front side of the trailer ),so I don't actually know how well or not the trailer might have done with good vacuum lines.Hope to repeat experiment one day.I hope for alot of things!----------------------------

Lets see a car/trailer image,then we can better advise.----------------------

I suspect you could improve flat-land mpg with the trailer and I'd love to see you do it.It's one way to create the ridiculously long tail the air likes so much ( see my photo=shopped Honda Insight micro-RV for a chuckle!).

[bbjsw10]

Thanks Aerohead, was hoping you would key in on this. Your opinion is highly regarded around here.

I will make a car + trailer image this weekend. The mpg numbers you had on yours are quite inspiring. With some time and planning I could see this working. Especially when you only had a 4 mpg loss with a car running that rich. It had to been increasing your mileage just no way to know it.

Could you post a link to that Insight RV? I couldn't find it.

[pugmanic]

Originally Posted by bbjsw10

Its a great idea, but then you have to take into account you have rigidly elongated your vehicle and therefore reduced the effective turning circle because of the way the back end will swing out on a corner.

Could you use vortex generators to re-attach flow to a standard tear drop trailer?

[bennelson]

I love the idea of a flexible gap filler between the car and trailer.

I have thought about that almost ever since I built my teardrop. I still haven't been able to think of an ideal material to do that with.

It has to be flexible, (so you can make turns!) yet not be flapping in the breeze the whole time. The best I can think of is something like Spandex, which would be pulled snug, but still have enough give for turns.

I would imagine snaps would be the best way to attach it, although Velcro could work too.

[trikkonceptz]

To seal the gap you could design a gasket like an inflated inner tube, with a release valve that would let air out when pinched in a turn, kinda like a bounce house for kids. This bag could be inflated with exhaust gas.

As far as using bicycle tires for the trailer, I use to build mini choppers with 20hp engines that achieved speeds upward of 90mph. Our first obstacle was the front tires. At first we used standard bicycle tires and were melting bearings @ high speeds. In the end we found high speed sealed bearings that would fit in the rim housings and all problems were solved moving forward.

[bbjsw10]

I have been thinking about the flexible gap filler, what about camper rubber roof. Water tight, tough, flexible and lasts for years. And for attaching what about using a track like a Jeep Wrangler uses for its soft-tops. This would work especially well with a double hitch setup no side to side just up and down to worry about.

[MetroMPG]

That Samurai owner could have saved a ton of gas by doing this :



But you're right, pugmanic: the swing arc would be ridiculous now!

Here's the Insight w/trailer photochop from Phil's album. Click to zoom: