04-06-2010, 08:49 PM
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#31 (permalink)
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Master EcoModder
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Motorcycle mirrors are (slightly) convex, if I am not mistaken. And mounting those with the angled stalk would be interesting -- maybe the 'L' can be positioned back, and the mirror has enough pivot in it to make them useful?
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04-06-2010, 09:44 PM
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#32 (permalink)
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Pokémoderator
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RandomFact314 -
Oh yeah, I have spent a *ton* of time scouring motorcycle websites and e-bay for mirrors. I do have a very cool pair of motorcycle mirrors that would have cut my side-view-mirror size in half (and looked good on the car, IMO), but I "leapfrogged" that possibility and I am presently down to one leetle bicycle mirror, so I don't have the need.
Neil -
Quote:
Originally Posted by NeilBlanchard
Motorcycle mirrors are (slightly) convex, if I am not mistaken. And mounting those with the angled stalk would be interesting -- maybe the 'L' can be positioned back, and the mirror has enough pivot in it to make them useful?
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I don't know if they are convex. Part of my old search was finding one that had a "practical" stalk that was useable for a car. The one in RandomFact314's picture is not designed to mount on the "vertical side" of a car. Instead it's designed to mount on something like the motocycle handlebar or cowling.
Another possibility is snowmobile mirrors. You can get small ones that are also convex. This is my favorite one that I never got :
Side Mirror Snowmobile Mirror Wing : eBay Motors (item 250240833784 end time Apr-14-10 06:30:51 PDT)
They are convex, have an adjustable mount that is compatible with cars, and they are *small*, 2.5" * 4". They don't have a stalk mount, but you can't have it all.
CarloSW2
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04-07-2010, 02:30 AM
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#33 (permalink)
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Master EcoModder
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Not bad, but they still have the bulky base, which is going to add wasted frontal area. Though I do like the convex glass, since it will allow you to use a smaller mirror.
I'm just going to stick with the $70 pair I found that'll bolt onto the side of the door, then just cut and tape some coroplast over where the old mirrors were. But that's after I get the money, since ordering the new tires cleaned me out for a while.
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04-07-2010, 07:42 PM
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#34 (permalink)
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So far I have to agree...
Quote:
Originally Posted by Old Tele man
...I think obtaining a "lowest drag" mirror is like "saving money"...where the best way to save money is to "...not spend it!"
...thus the lowest drag mirror is NO external mirror (use a camera!)
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There doesnt seem to be anything available that will mount easily and
look OK and actually make much difference.
So for now, I am moving onto other aero mods I can actually do for little to no $$$.
Under belly pan, front upper grille delete.
Larger, skinny tires, full moon hubcaps.
Later maybe a full vinyl fabric aero bra to smooth out the entire front
of car.
Thanks everyone for the mirror info.
Pete
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ScanGauge II, Unibrow(1 wiper) Air Intake, Mud flap delete, 3.5+" Front Spoiler, Full Moon Hubcaps(Lost). Upper Grille block. (New and improved Fall edition)
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04-08-2010, 01:48 AM
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#35 (permalink)
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Master EcoModder
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Thanks for all the input.
Coupla thoughts:
Closer to the window glass probably = slower slipstream than further out, for lower drag since drag increases exponentially with airspeed
Use Great Stuff polyurethane insulation foam to make streamlined shapes of stock mirrors? That way, a flat mirror and its stalk could be easily sculpted to much more aero shape.
Best idea might be clear model airplane canopy over smaller mirror pretty close to the window glass. Go on Youtube with keywords "plastic vacuum forming" or similar and see how to do this in your kitchen oven + shop vac.
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04-08-2010, 07:56 AM
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#36 (permalink)
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EcoModding Lurker
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I think these may be the most aerodynamic I've seen
Doesn't it make sense to follow the teardrop shape for mirrors?
http://www.racemirrors.com/engineering.html
At least thinking in mirrors alone - without car - it seems logical to me
For a complete solution (car+mirror) I wonder if the solution found in some Opel would be good for any car
What do you guys think of this??
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MrK
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04-08-2010, 11:26 AM
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#37 (permalink)
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Aero Wannabe
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The Racemirror with the clear extension may indeed be the most aerodynamic mirror out there but at $135 each it would take decades to break even on fuel savings.
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https://ecomodder.com/forum/showthre...tml#post621801
Quote:
Originally Posted by freebeard
The power needed to push an object through a fluid increases as the cube of the velocity. Mechanical friction increases as the square, so increasing speed requires progressively more power.
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04-08-2010, 12:31 PM
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#38 (permalink)
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EcoModding Lurker
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I totally agree with you COcyclist, I think no mirror will save you more money than it costs, and with this one is more true!
But I always think in modding my existing mirrors to get this shape
Even I can use a plastic bottle to do this clear extension, even if I have to change it every 2 months or so (sunlight will degrade it) it may be worth...
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MrK
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04-08-2010, 02:08 PM
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#39 (permalink)
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EcoModding Apprentice
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An issue I've noticed on my car (with no side mirrors) this week with tuft testing is the assumed horizontal airflow around the mirror is not correct (at least not on my car, I think most others would show similar results). The airflow where the mirror was is actually inclined in an upward direction (about a 45 degree angle or therabouts) so mirrors that look great for horizontal flow are not even close to good for what's actually happening. I see many mirrors that are flat on the bottom which seems to be the about the worst design.
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The Following User Says Thank You to robertwb70 For This Useful Post:
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04-08-2010, 11:32 PM
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#40 (permalink)
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Master EcoModder
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Hi Robert,
What you say seems to coincide with a drawing from the Hucho book "Aerodynamics of Road Vehicles":
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