Side Mirrors...
 

I was thinking of replacing my big side mirrors with little tiny 3 inch side mirrors that are usually just use as wide blind spot mirrors. then id probably fit a another mirror inside the actual car for added safety

by making my mirrors 1/4th the size that they were, that should really help with drag right?

do laws state that side mirrors need to be a certain size? or that you just only need a mirror and nothing specific?

South Carolina law just stated that you need a mirror that can see 100 yards behind the vehicle and that you only need side mirrors if you can’t see out through the interior mirror, no minimum size given. On the Aerocivic, I removed the external side mirrors and replaced them with smaller side mirrors mounted on the door on the interior side of the glass. As long as I didn’t pile luggage inside to the point of blocking line of sights for the main interior mirror, I was fine. Every time I got pulled over by cops curious about the car, I would ask them if anything about the car was illegal, and none of them had any complaints about the mirrors. Removing the exterior side mirrors reduced the wind noise inside the car considerably since these wind noise generators are located about 2 feet from your ears on the opposite side of the glass.

On my panel van I had two [approx. 2.5x4"] rectangular convex mirrors . The rear window was about the size of a piece of legal-sized paper.

Objects 100 yards behind were visible, but very small. Peripheral vision and situational awareness were good.

See I’m trying to avoid getting pulled over period. I’m technically running 15 percent “ illegal” window tints but cops here don’t care unless you give them a good reason to pull you over. I have 1300 dollar nano ceramic tints all around that block 98 percent of IR rays. They allow me to run my ac at only a fan speed of one in my black car, even in hot Arizona summer deserts. It’s amazing. That obviously helps save gas. Probably not 1300 dollars worth of gas, but extra privacy and comfort from the sun is nice. I just try to avoid getting pulled over because I don’t want a “ fix it” ticket


If I get small little micro side mirrors, I’ll probably also have to fabricate some type of mini aero curved shell on the leading side so it’s not a hard flat base pushing into the wind

Windshield included? Uprated headlights?

yup. 70 percent on the windshield. xpel xr plus all around the whole car

headlights are the brightest LEDs on the market currently according to bulb facts and third party testing. even have my reverse back up lights upgraded

heres a video i made last year of my headlight upgrade. over 300 percent brighter

https://www.youtube.com/watch?v=kFl6QOAS9Kw

<iframe width="560" height="315" src="https://www.youtube.com/embed/kFl6QOAS9Kw" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>

Took of side mirror as a test to see how it would look. These are the slots. What have others done to cover this area up or make it more seamless? I’ll probably replace the mirrors though with little skinny 3 inch mirrors. I kind of dig the mirrorless Ioniq look. Gives it a bullet like appearance. Especially being black with tinted windows

Indiana law is just that you need a mirror to see 200 ft behind you. That's all the law says. Nothing stating where or how big.

I used a piece of sheetmetal cut to shape. Put weatherstripping along the edge and painted it black. Then used the domed allen head bolts to attach it.

https://lh3.googleusercontent.com/Aj...V=w714-h951-no

I siliconed plastic covers on the truck:

https://blogger.googleusercontent.co...405_121037.jpg

On the Prius, which has door-mounted mirrors, I fiberglassed over the hole:

https://ecomodder.com/forum/member-v...525-163059.jpg

Before you fit smaller mirrors, test them to see if they are actually lower drag than the larger stock mirrors; they may or may not be. Something like this will tell you which mirror has lower drag (the one further from the pole's centerline when there's no torque developed):

https://i.postimg.cc/YCVXVtsz/Figure-5-7.jpg

But that isn't the whole story; you'll also need to investigate whether the lower-drag mirror by itself is also the lower-drag mirror next to the car, where there is interference between the mirror and body.

I've seen that video. im not even thinking about using smaller car mirror. i was actually going to stick a screw out and then attach one of these super mini 3 inch blind spot mirrors. and then id fabricate some type of little aero cover shell on the backside of it facing the wind. ill be getting a rear view panoramic mirror and then also putting two little mirrors on the inside of both windows too for extra safety

https://m.media-amazon.com/images/I/...AC_SL1500_.jpg

That's fine--but if you want to know if the smaller blindspot mirror (with or without fairing) has lower drag than the stock mirror, you will need to test it. There's an unfortunate belief on this forum that you can assess the aerodynamics of an object or shape simply by looking at it when this is not true, especially when it comes to small add-ons subject to interference drag in areas with complicated flow patterns such as mirrors. (You\'ll find statements to this effect in any textbook on aerodynamics; I know because I\'ve read a lot of them! You can--and should--too).

its hard to do the t shape test thing because ones a 5-10 pound mirror and the other is as light as a feather. 8 by 6 inch electric mirror, versus a tab the size of my thumb

Do you actually want to know if your modifications work, or not? Because every time I've suggested testing something on this and your other thread you've come back with excuses why you can't. You're not alone; this is unfortunately a common attitude (and I used to be the same way), but it's one that needs to change if you want to engage with the real world of aerodynamics and not "mathematics from fantasyland" (to borrow a phrase from my first- and second-semester calculus professor). It's why I wrote this piece a few days ago.

I’m asking for a better way to test. I can do tuft testing for side mirrors easily. But the whole wooden T bar thing like in Julian’s video only works if the two mirrors are the same weight. What I’m asking is how can I get around the inside weight difference? Even if the little thumb tab has more drag hypothetically, the wind in that specific test isn’t going to move back an item that weighs half a gram versus something that is 10 pounds for the full size mirror. You’re not factoring in weight. I’m sure some time of T bar that’s mountained to a super slick pole that’s mounted on a high grade ball bearing could possibly over come the weight difference and be more scientific. But the two mirrors on the stick thing isn’t going to work with such a massive weight difference. That’s why I’m asking if there’s a better test to do

Maybe the aero cover shell of the mirrors of some sports motorcycle might serve this purpose.

Why do you think the weight would make a difference? I think I see what you mean, is it because it's gonna take more force to move the heavy mirror? Or because holding a pole with 2 uneven weights while keeping it mostly straight up could be challenging?

because itll take a lot more force to move the heavy mirror yes.

In some alternate Universe, in the last few days, I saw and maybe even quoted a picture that showed a stock mirror vs one of those blind-spot mirrors inside a [3D prionted?] shroud.

It wasn't this thread or the Ioniq one. There was a thread where everyone compared inside mirror setups. Perhaps linked from ecomodder.com/wiki/Side_mirrors.

edit:
It's a couple.
The pitfall would be binding on the axis.

F=MA

Force
Mass
Acceleration

The heavier mirror would only require longer to move to its resting position at the chosen speed. The force from drag will be a relative constant. The mass will be constant for each mirror. So the only change will be the acceleration rate. Weight is a factor, but if you wait for things to settle out it will be accurate.

I do agree about finding a more convenient test. Julian had a sunroof available. I don't and unless I make a fixture or hang out the window it's not really an option. Unfortunately I don't have any suggestions as far as an easier test.

duckduckgo.com/?q=swan+hood+ornament&iar=images&iax=images&ia=ima ges

Does it make sense to move forward instead of up?

F*=MA
*there will be a trig fuction for angle of attack. ...absent a linkage to reverse the force across the vertical axis.

Adjusting the spacing of the mirrors accounts for the angle. Not sure what you are trying to say with the second half.

I mean I’m going to try and make an aero cover that’s the same shape as the OEM mirrors, and then put that over the little 3 inch tab. I’m currently trying to figure out how I’d mount that little sucker though…

That picture [which I apparently hallucinated] had the long edge of the blind spot mirror against the A-pillar, with a cover shaped like a fat louver.

3-inch diameter
 

There may come a time when the only difference between a collision, or worse, will be instant, visual situational awareness.
The temptation of low-drag has the capability to blind us into missing the premise of some OEM equipment design, and the human factors research that went into the final product.
If nothing else, you might just look at the mirrors on the lowest drag extant production vehicles, and see if you can identify associated trends between their designs, depending on mounting strategy.
Fair market price for mirror wind tunnel testing and validation is $4,000/hour.
Let Tesla, Porsche, Jaguar, Chevy VOLT-II, etc. show you their 'solutions', on their nickel.:)

I’m essentially going to have 5 mirrors. If anything, my visibility should be even better

Two blind spot mirror tabs on outside of car, 2 regular depth square mirrors inside the windows, and then a curved ultra wide rear view mirror hanging

Also random question for the super aero math people, most of the tests that mention side mirrors being about 3 percent of drag, give or take, seem to be tests done at the classic 55mph. So I’d that a static or fluid/compounded percent? Does the 3 percent effect Increase the faster you go?

Obviously mirrors have barely any affect at 30mph in the city. And then tests around 55mph show a measurable drag increase. So would drag multiple even more when you’re going 80-90 mph and you see even more benefit of removing the mirrors? Or would it still stay at that 3 percent they claim

Sorry for such a noob or ignorant question. I’m just trying to soak in all of the knowledge I can!

mirror effect
 

Don't ever stop asking questions! The most stupid one would be the one never asked.
As you've asked it, I'm unsure that the specificity of it has been properly addressed.
Here's some points to ponder:
1) The mirrors are only a fraction of the frontal area of the car.
2) Their frontal area and interference drag is part of the car, although one might wonder if the vehicle's critical turbulent boundary layer would be achieved in advance of the mirrors ( if you treat the mirrors as 'satellites' which orbit in formation close to the host vehicle ).
3) The small size of the mirrors suggest that their own Cd will not become 'constant' until a higher velocity is achieved.
4) Which begs the question of whether or not the 'vehicle's' Cd would require the higher velocity to 'flatline ' its Cd.
5) Convention has it that, around 20-mph, the vehicles Cd is 'fixed.' Warts and all.
6) If we accept that, then whatever percent of the total drag we attribute them to, that percentage would remain a constant, until the vehicle reached transonic velocity, where the air began to compress, and shockwaves could begin to form on certain areas of the vehicle.
Is that cloudy enough for you?:p

I'll side with J. Edgar and Vman455 on that, you'd have to test it.

Large scale vs small scale times Reynolds Number sort of thing.

thanks for that answer. any suggestions on how to mount the little side tabs? off the top of my head, i was thinking of getting a tiny block of wood thats a few inches long, drill a 10mm screw into it, and then just insert it into one of the 3 10mm hole slots from the former mirror, then just stick the 3m tape mirror onto that little wooden arm sticking out. maybe use some high grade gorilla glue combined with the 3m sticky thats included. then obviously build some type of aero shell around it

wood, screws, tape
 

You could certainly mock it up that way, just to see if you could live with the optics of it.
If you like the mockup, then translate that into a structural metal strut , for safety, and some means in which to 'gimble' the mirror for 'aiming.'
The strut could be streamlined after the fact. and some permanent fairing over the new optics.
Technically, the mirror needs to be tested in the exact location in which it will reside. It's the only place where the local flow will be whatever it's going to be.
As a first principle, the mirror fairings on the 1996, PORSCHE 911 GT1 race car, would be an example of a near-minimum drag form, according to Sighard Hoerner's drag tables. You must consider them in the context of their type of stalk, and mounting location on the Porsche.

i like that shape. just gotta figure out how to mold that to be super small

how
 

There are some great videos on composite tooling on YouTube.
They create a 'plug' which is a life-size mockup of the housing.
From that, they create a female mold.
From which the actual part will be made.
Having a 'round' mirror allows both left and right housings to be made from the same tooling.
Anyone local, with a wood lathe could turn the plug.
Take it from there.
The skills you learn can be 'scaled' for larger composite projects.
Rick Dale, of 'Rick's Restorations' charges around $125 /hour to clients for the same kind of skills.

these are about the same size as the mirrors. was just going to cut one in half, spray paint it black and put it on the other side of the mirror

https://m.media-amazon.com/images/I/...AC_SL1500_.jpg

Sometimes, while other parts of the vehicle cause an even greater drag, the mirrors are not that bad of an issue even at a considerably higher speed. But anyway, I don't remember which speed and subsequent increases would increase substantially the performance required to achieve, and thus the fuel-efficiency would go down in the same proportion.

painting plastic
 

Ask around about proper adhesion to plastics.
Epoxy primer is very popular now. It may adhere better than conventional lacquer-type.
It would suck to get a nice top-coat on, only to have it all slough off.:o

Really nice oval ones at the dollar +.25 store that glue well with 3m Weatherstrip. I use them for DLG glider fuselages

Sideways thinking: for estimation/prediction modelling, the phone cad software packages would predict effects close enough for government work.

Set up my panoramic wide angle rear view mirror. Can easily see cars in the blinds spots without moving your head. Also the two mini tab mirrors that will be placed outside the windows came in. I also have two little flat square mirrors I will mount inside windows just Incase

Should be removing the side mirrors next week

At what speed would I even see an mpg improvement? Obviously I won’t see much at 30 mph around town. All the tests I see online are at that basic 55 mph range. Would I see an mpg gain even at 50 mph? How much should I see at 90 mph?

A-B testing would have the answer.

I have a convex clip-on mirror a little narrower that yours in the Metro. The 2.5ft wide Wink mirror goes back in the Superbeetle (from the Dasher) as soon as I find the brackets.

Small blind spot mirror - I've been using this for the past several years with no issues. Definitely less drag than the massive stock mirrors, and the convex shape of the mirror + panoramic interior rear view mirror basically eliminate all blind spots. Passenger side mirror is completely deleted.

Link to picture of my setup: https://ecomodder.com/forum/showthre...tml#post587745

Whether or not it has less drag than something like this remains to be seen. Some state inspections require the side mirror to be adjustable, in which case the motorcycle mirror would be necessary.

These let you rotate and angle and adjust them. I liked what you did with yours. Wish I had thought of it before I bought these. Clearly these are significantly smaller than the OEM mirrors. Heck they are smaller than just the mounting arm sticking out. I just need to install these on the side of the window with an OEM style look