Ok, I'm about to buy new side mirror for my 96teg. First to reduce drag and 2nd to reduce weight.

Now, there's 2 differents type I'm interessed in... The Spoon type or the TCS type (F1 like)...

Is there issue I should know before making a choice... I was wondering if the TCS could hold 140mph without moving...

Any constructive comment will be appreciate!

 

I just ran out and hugged my race car just now.
Thanks for reminding me.

I use stock mirrors and dont see any need to reduce weight or drag in that area.
Its like removing your antenna cover and replacing it with a piece of sheet metal.
I dont think noticable gains will be made from spending that kind of money.



[QUOTE=maxogsr;43294054]Ok, I'm about to buy new side mirror for my 96teg. First to reduce drag and 2nd to reduce weight.

Now, there's 2 differents type I'm interessed in... The Spoon type or the TCS type (F1 like)...

Is there issue I should know before making a choice... I was wondering if the TCS could hold 140mph without moving...

Any constructive comment will be appreciate![/

 

yup, hugged mine too. checked mirrors.......... stock

 

lol I want to hug my future race car but I can't ? Still stuck in Indy.


About stock mirrors it's like having to hugh hands outside of the window trust me their is a lot drag. Now if you can notice the difference or can you money be better spent else where now thats the real question. hummm?

Where is Johnny Mac?

 

Craft Square or APR? I agree though you can use the money more effectively elsewhere.

 

Just re-hugged my race car.. and yes Johnny would be a good one to confer with.
Now if you could get some penske mirrors like what was the controversy at Indy a few years back.
Those were good for a couple MPH over the whole field.
Team Penske kept them covered until it was time to go on track so nobody would try and copy them before the 500.

 

Thanks guys for advices and being worry about my wallet but now I'm there... Mirror are about 1% of the total drag of a car. 1% + other 1 % + an other 1% will make at the end 5-10%. It part of a whole... It's like shaving weight... Bunch of my bodies always says :" ah it's only a 3lbs lost blablabla" but at the end, by cutting all those 2-3lbs everywhere, now the car is 400lbs lighter and way more faster on track... To win you need to work around details and have a bit of luck sometimes... Mirror weight at leat 3-4 pound each (power one)... So I might save at leat 6pounds plus I will improve drag...

And btw I don't have antenna anymore. Aren't we in the race+autox forum?

So back to the topic... Anyone know if the F1 style that they sell on ebay are good to hold up about 140mph?

 

All valid points. The biggest problem I've seen from running aftermarket mirror and it might only be limited to me and my car is that the shake so much that it makes them useless. Guess it depends on what mounts you are running.

 

less visible area too. i have the "f1 style" and if i didnt have a wink mirror i would already be back to stock. i have each mirror set to a certain spot.."blind spots" if you will. also the problem with them is people in the paddock or hotel etc bumping them and their adjustability isnt the greatest either.


and you are still in indy. ****..we karted last weekend. also there is an autox tomm. www.indyscca.org at the old bush stadium where the indians used for play. /thread jack.

 

Aren't the F1 style suppose to be convex?

 

Good thing to know...

Maybe putting some rubber washer in between the mirror and car would help... just an idea like that...

 

you can get them either way. i have convex but it still has less "visible" area than the oe mirror.

 

I wonder if i took a manual mirror and reconstructed it with a fiberglass shell but some how made it more aero like so it would flow better in the open?
Here is where a wind tunnel or big fan and some smoke would come into play to see of it actually made a difference in drag.
Also what would make it more aero like.. a sharp wing like angle or golf ball dimples.
Scott... who would probably lose sleep over this if he read it!

Just re, re-hugged my race car, now its time for some coffee

 

Golf ball dimples I doubt would help on a mirror. Their purpose is to create a turbulent boundary layer which resists separation of the main flow stream. The sudden drop off on the back of the mirror (where the actual mirror is) will make flow seperate under pretty much any condition. Just my theory.

 

what about enclosing the drop off area behind it in a see through lexan bubble lol j/k.

 

i pushed my "race car" out of the garage and back in after i cleaned it last night.

and you didnt read the latest grm issue? cheap hillbilly windtunnel..2 floor fans behind you and after a few mountain dews you just start wizzing away. flow seperation is FANtastic!

 

hahaha. snow globe racing mirrors!

 

There goes my Lucky Charms

 

Coffee done... re re re hugged my race car, and then I started to think about the stock manual mirror redesign.
They are a bigger mirror...
Creating a new more aero like mirror shell and retaining the line of sight of the stock glass.
Could it be as simple as making the back of the mirror more tapered?
Halving the mirror and the portion that actually hits the wind be more knife edged?
Im off to the garage to check into this.
Two floor fans huh??? Im gonna have to try this technique.

Scott... who lives far away from me may be trying to communicate via mental telepathy.

 

The OE side mirrors are in fact heavy, high drag, and of course to allow you to see any cars next to you. I once computed my CRX mirrors may contributing as much as 5% of the total aerodynamic drag all while weighing 3.5 lbs each. So back in 2003, I contacted APR and got a set of their GT mirrors for a Mitsubishi Eclipse. Since they didn't and I believe still don't make a GT mirror to bolt up the the CRX, the closest fit for the triangular area on the door where the mirror mounts was the Eclipse mirror. You have to drill your own holes and trim some of the mount, but it looks good once you modify it. Of course, if you have an Integra or an S2K or other Honda model, then you don't have to modify the mount to work.

The APR mirror looks good with its tiny carbon fiber pod with a rounded frontal section - unlike the flat sided OE CRX mirror - and housing a low-distortion mirror element. It is lightweight, actually very light which of course is a good thing. I believe it trimmed a good 4 pounds from my car. Obviously, this isn't a lot of weight but every little bit counts. Especially considering you could buy a $1000 titanium bolt kit from Baller Bolts that shaves only 3 pounds. So the mirrors are lighter, functional, stylish, save more weight and are cheaper by $700 or $850 if you qualify for the APR discount.

Now, for the downsides of the APR or similar mirrors. First, the miirror pod is attached the door mount using a strut with a ball-swivel to allow a good range of angular adjustment. the swivel ball resides in a boss and is fixed in angular position with a plug that is tightened against the swivel ball. Unfortunately, the very small ball diameter requires a large preload to keep the mirror from moving while on track. And with such a large preload, the ball can shed some material in the metal to metal joint. When this happens, the mirror gets loose again and you have to remove the mount base from the door to preload the swivel ball all over again. APR should use a larger - like 50% or even 100% - ball diameter to minimize this problem. However, once you figure out how much to adjust the preload, you shouldn't have too much problem as long as someone doesn't move your mirror causing it to become loose all over again.

In addition to the swivel ball diameter, the mirror area is small and some people complain about this. I don't consider this a problem since I use the mirror for my racecar only and not on the street. Maybe if you use this mirror on the street, you would think it is too small. On the other hand, APR does make a slightly larger mirror and maybe this would suit more people.

 

5% is arguably significant with a CRX's stock hp. I wonder if there are any other aftermarket solutions that would help by a better shape if not necessarily size?

Both the Spoon and the "M3" style mirrors are more contoured, and a little smaller.

Also there's the "SLR" style. They appear to be smaller more like the F1, but inside a housing, so the adjustment point is protected from drag... though I'd rather do without the LED lights:

 

Kewl there is pictures of my car in on their website.
Phillip Chase's old Tein Civic.

Thanks for chiming in Johnny.. Its always good to get the opinion of an aeroguru!

I dont see their Eclipse mirrors there though. Perhaps it's a discontinued item?
260.00 a pop and it will wiggle and move.
There has to be a cheaper and sturdier alternative?

 

ALL MAN you should have told me I being attack by bugs left and right and stay in the hotel all day because the heat is trying to kill me, I would have love to go go karting and I might check auto x if I get a chance. LOL

 

I would use something like this mounted inside so there would be no drag.

 

Sorry about not writing too much about the APR's aerodynamics in my previous post, but I had to leave the house before getting finished with my review on the APR mirrors. So I continue now...

The APR GT3 mirror pod is rectangular at the back and measures approximately 2.125" X 4.5" (cross sectional area: .0664 ft^2 each mirror) whereas my stock CRX mirror measures approx. 4.5" X 9" ( CSA: .281 ft^2 each). The APR's side view projection length is 2.375 inches and the stocker is about 2 inches. Also in the side view, the APR is wedge shaped with radii at the leading edge and near the back and from looking at Hoerner's "Fluid Dynamic Drag" I can estimate the 3-D profile drag coefficient (Cd) at about .6 and the stocker at about .7. These numbers are approximate and the only real way to find out is to test them in the wind tunnel. However, I do feel that the difference in the drag coefficients of the two mirrors or .1 is relatively close.

The other issue that isn't so easily resolved is the mirror's affect on interference drag. The Cd. numbers mentioned above are for an isolated mirror. That is, the Cd is for just the mirror. Now, when you place the mirror near another body - such as the car's body - the overall drag on the car and mirror will be different than adding the drag for just the car alone and the drag from the mirror alone. The difference between the overall drag and the drag of each component separately is called interference drag. Once again, the interference drag must be determined from wind tunnel data. One thing we do know, the farther away from the body the mirror resides usually results in less interference drag. But for arguments sake in comparing the APR mirror to the stocker, lets assume the interference drag is the same for both mirrors.

For the CRX, reliable information shows the Cd = .36, the frontal area = 18.51 ft^2.

So at 100mph, the estimated drag on the CRX = (Cd = .36) X (dynamic pressure = 25.6 psf) X(frontal area = 18.51 ft^2) = 170.6 lbs or 171 lbs. BTW, to make the numbers make sense, we can see how much power the aerodynamic drag is consumming. In this case, drag horsepower = drag X speed = (170.6 lbs drag) X (146.667 ft/sec) / (550 lbs-ft/sec) = 45.6 whp. So drag is eating up about 45.6 wheel horsepower.

So, lets look at the effect of using APR mirrors verses the stockers:

APR:

Drag = (Drag coefficient) X (dynamic pressure) X (cross sectional area of both mirrors)

Drag (lbs) = (.6)(25.6)(.1328) = 2.08 lbs

Stocker

Drag (lbs) = (.7)(25.6)(.562) = 10.07 lbs (5.9% of total)


So, lets see how much speed we can pick up with the CRX by just changing the Stocker mirrors out for the APR GT3 mirrors.

With APR mirrors, the overall car drag reduces from 171 to 162 lbs. With the APR mirrors, we can now get to a speed of 102.4 mph with the same drag as we could get withl the stocker mirrors.

Speed new = Speed old X (171/163)^.5 = 102.4 mph

If you you remove all mirrors like I do when racing at California Speedway, the extra speed becomes 103 mph for same drag as the stock CRX's drag at 100mph.

Obviously, this whole exercise is what we would refer to as an estimate based on the best knowledge we have. I have left out a few things that would need to be looked at for a better estimate at the actual improvement on performace.

1. A racecar has it's windows down. This will greatly affect the overall aero character of the car and thus the Cd estimate of .36 for the car may not be realistic.

2. A racecar is lowered which generally helps reduce drag as long as the car is set at a ride height where boundary layer affects become important.

3. Interference drag was dismissed due to the complexity in its computation. This is especially true due to the affect of the mirror has on an open window.

4. The CRX racecar has larger tires which will undoubtedly increase the overall Cd and frontal area of the car.

I would love to do appropriate coast down measurements to determine a closer approximation of the drag improvement of the CRX or any other car.