Aero Trailer? Could it help FE?

[mtgeekman]

I was wondering about that type of a boattail/ trailer for the insight and what it would do to the Cd.

[FunkSkunk]

I GOT IT!! Ok so adding the trailer is great for aero but why not combine that with an Electric Fifth wheel! (I call dibs on credit if someone builds it) Somehow you could make the wheel or wheels on the trailer electric and assist with forward moment at slow speeds! I know, I know with it attached to the trailer how do we keep it going straight... but that's for you guys to figure out I just get to keep the royalties!

Fifth wheel info --> http://ecomodder.com/forum/showthrea...brid-1191.html

[aerohead]

I'm guessing on the order of Cd0.12.There is no wake,and the kinetic energy of the original turbulent wake behind the Insight has all been converted to higher base pressure,basically eliminating the profile drag altogether,leaving only skin-friction drag and perhaps a bit of induced drag at the windshield header and A-pillars,and a little interference drag behind the sideview mirrors.----------------- HONDA has achieved Cd 0.10 with their Dream-2 solar car,I believe the Taruff twin-boom also had Cd 0.10,and many Bonneville cars (like" Pumpkin-Seed") have Cds on the order of 0.12.Seems like Cd 0.12 could be doable with the trailer.I intend to find out.

[aerohead]

Originally Posted by FunkSkunk

I GOT IT!! Ok so adding the trailer is great for aero but why not combine that with an Electric Fifth wheel! (I call dibs on credit if someone builds it) Somehow you could make the wheel or wheels on the trailer electric and assist with forward moment at slow speeds! I know, I know with it attached to the trailer how do we keep it going straight... but that's for you guys to figure out I just get to keep the royalties!

Fifth wheel info --> http://ecomodder.com/forum/showthrea...brid-1191.html

Sorry,you're too late on that one.Others and myself have already done that one.My concern was with safety,as in an emergency evasive manuever,you've already got your hands full trying to stay alive,let alone having to deal with a traction drive unit behind you applying forward thrust to a car which may be already yawed.---------------------- And since braking may not be the first instinctive reaction in some collision scenarios,it would take a very "intelligent" safeguard system to dis-engage the unit under duress.----------------While I think a streamlined pull-behind power unit for plug-in electrics would be great for cross-country travel,I remain very wary of a "pusher".Just my opinion.

[mtgeekman]

If you are going to build on I hope you will take lots of pictures and I cant wait to see it!

I can also see the advantage of it being a power source. Maybe it would be a good place for the V-Boost stuff for the MIMA system.

[aerohead]

Originally Posted by 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.

I wanted to throw out an idea,yet unrealized for both the 1 and 2-wheel trailers.I will attempt four rigid panels,hinged at the rear of the car,projecting horizontally rearward.When the trailer is straight,the panels "nest" together,held in slight tension by an interlaced cable/pulley system with spring tensioner.In-line skate wheels project beneath the trailing edge of each panel,just touching the forward face of the trailer,which is wedge-shaped.------------------------

As the vehicle turns and the trailer pivots,the appropriate roller forces it's panel to swing away,riding up the wedge to allow clearance for the turn (much as basjoos and Darin's rigid front wheel skirts),acting against spring tension.-----------------

After the turn is negotiated,the panel recedes to its "stowed"position,pulled back in by the cable/pulley/spring.-----------------------

All the panels contact one another with chamfered 45-degree edges which cannot bind,and remain nested until the next turn event.-------------

Likewise,any "vertical" event is handled above and under ( like rolling over railroad tracks,steep driveways,etc.),with cable/pulley/spring raising the lower panel,the top panel aided by gravity alone.---------------------------

I meant to have all this on the 1-wheel trailer for the test,but as it happens,reality intruded upon my dreams,and at the alloted moment,had to leave,ready or not.-------------------------

Test data for 18-wheelers have shown this gap to be profitable if sealed and I have to believe it would also pay dividends to ecomodders,regardless of how it is accomplished.

[bennelson]

I was also thinking that some sort of rigid panel system could work well, but couldn't think of good mechanicals for it. But it sounds like you have it pretty thought through.

[aerohead]

Originally Posted by 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.

I'm not sure about other states,but if DOT isn't stamped on things,it won't pass muster with state troopers and such.It is possible also,that at some tangential loading (in a curve),that a bicycle wheel would simply "fold",since it can't "bank",something it's bearings are also not designed for.Just a thought.

[whokilledthejams]

Originally Posted by aerohead

I'm not sure about other states,but if DOT isn't stamped on things,it won't pass muster with state troopers and such.It is possible also,that at some tangential loading (in a curve),that a bicycle wheel would simply "fold",since it can't "bank",something it's bearings are also not designed for.Just a thought.

All good points.

I was thinking spindle-mount drag fronts for trailer tires, but I can't find any on the intertubes that are DOT legal (Hoosier makes DOT tires, but specifically says not to use them on public roads-- it has more to do with meeting drag racing rules than being street legal). Same goes for dune buggy fronts, AFAIK.

Still, most normal trailer wheels are fairly small, especially if they don't have to be able to carry a lot of weight.

Perhaps motorcycle wheels and tires might work? They can be had in spindle-mount applications, and tend to run tall and skinny, while still being road-legal.

[aerohead]

Originally Posted by whokilledthejams

All good points.

I was thinking spindle-mount drag fronts for trailer tires, but I can't find any on the intertubes that are DOT legal (Hoosier makes DOT tires, but specifically says not to use them on public roads-- it has more to do with meeting drag racing rules than being street legal). Same goes for dune buggy fronts, AFAIK.

Still, most normal trailer wheels are fairly small, especially if they don't have to be able to carry a lot of weight.

Perhaps motorcycle wheels and tires might work? They can be had in spindle-mount applications, and tend to run tall and skinny, while still being road-legal.

There was a set of spindle-mount, drag wheels(spoked 60s style) at a Goodfella's Hot Rod Show and Swapmeet last month here for $100 (US).I passed 'em up cause they were"for racing only" stamped,and I figured,sure enough,if I try an' run 'em on the street or highway,I'll get nailed for sure! They were for early model ford,were absolutely beautiful but I got scared off.--------------

I've got a Suzuki TM-400 moto-cross rear swingarm and wheel on my one-wheeler and so far no one has picked up on that.It's got really robust spokes,a good road tire, and I've tossed the trailer around hard over three states and she's done fine.( but I never said that!).-------------------

I have thought of mating a trailer spindle to an s-shaped swing-arm (as sport-bikes have with uni-strut suspension) and just use a 13-inch radial trailer tire/wheel combo.They're designed for this kind of duty,are DOT-rated,and can be had at Northern Tool pretty cheap.The motorcycle wheel/bearing unit seems to be an unknown quantity because of the "upright"geometry it would see with a trailer.Perhaps a forged alloy wheel and LLR radial would bolt-up.-----------------

If the RR of motorcycle tires is that big of an issue,this may be a way to go.Had the carburetor hoses on the CRX been okay,I might have had usefull info on that issue.Rats!