THEY WORK!! NOW READ ON!
I used tuft testing to see the improvement or lack of from these very famous vortex "vortekz" generators.
I used 4" pieces of yarn-like string, and applied them all over the rear window.
The car used is a 2007 Mazda 6i. The car does have a complete front grill block. Aside from that it is not lowered, or altered in any other aerodynamic way.
The Procedure;
I drove on a somewhat flat road, at
ONLY 45MPH. (held with cruise control so speed was constant. There were also no crosswinds. The pictures are going BOTH ways of the road; again, to minimize any crosswind effect).
I concluded that even a small change in the tuft will mean a much bigger change on the highway at 60+ MPH velocities.
Also, this testing was done just earlier this morning, and the testing was done about 3 hours or so appart from each other (the time it took me to add the "vortekz" generators). So the conditions of the day, or the weather, could have and did not dramatically change.
Now, this is
BEFORE THE "VORTEKZ" GENERATORS
Here I marked the strings
RED so that they would be more visible.
NOTICE how the strings in the middle of the windshield appear to be in A LOT of turbulence. They even twist back towards the front! This means that the air is separating from the window and coming back the other way towards the front; creating turbulence.
Again, this is only at 45mph so the effect at higher speeds would be much much greater.
"Vortekz" Generators Applied
I placed them following the instructions, with the suggested (0, 5, 10, 15 , 15) degree placements.
In order for them to stick better I heated the 3m tape on both sides with a hair dryer for about 15 seconds. And let me tell you, I do not see how these could come off anytime soon!
They were sticking without even any pressure being applied to them! They are constructed very well and painted perfect (i got the painted version not the primered one).
They actually look really really good (I Think), and if they didnt work I would probably still keep them for looks
TESTING WITH THE "VORTEKZ" GENERATORS ON
Same road, same wind conditions, same 45mph speed. NOTHING was changed except the addition of the vortex generators.
Here I marked the strings
RED so that they would be more visible.
NOTE how the turbulence in the middle of the window is gone! Completley gone! All the strings face the same way they should have in the first place and (not apparent in the pictures) they were actually "tighter" indicating that they had faster wind speed over them.
Conclusion
THEY WORK! Even at 45mph they did a great job of straightening the flow out throughout the whole window and most importantly in the middle of the window where the most turbulence was being caused.
When i started driving, I was completley amazed to see such a big change. I was NOT expecting these huge results- considering i was only going 45mph I was truly amazed, truly amazed.
NOW! My observations from this is that, obviously, they will work even better at higher speeds. So the simple $20 purchase in this case was more than worth it. How this reduced turbulence adds up to greater FE... that I don't know for sure but less turbulence has to be greater FE right?!? More aerodynamic?!?
Notes!
Not because it worked on my car will they work on every other car!!
I think that as long as the rear slant of the rear window is somewhat like my car the results could be similar.
However, i just dont see it working on hatchback designs or trucks or the suck. Why? Well, these vortex generators are designed to keep the airflow attatched to the car, but if there is no more car like in the case of hatchbacks or trucks or suv's, then what is the airflow going to attatch to?
I think in that case they would probably just create more drag, and you could not really test them unless you were in a wind tunnel.
ONE LAST COMPARISON. LOOK AT THE TURBULENCE IN THE MIDDLE JUST DISSAPPEAR!
^No Vortex Generators
^Vortex Generators
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