Hypertek

iTrader: (3)

anyone ever thought about puttin some on?
http://www.manufacturersdepot.com/SPD/vortekz-universal-vortex-generators-black-10-pack-vortekz-vortex-generators-are-universal-to-fit-virtually-all-cars--trucks--vans--suv's--rv's-etc-----800000A6-1180622063.jsp
some Z guys are doin em


Im curious how much of an improvement it may do. Im all for aerodynamic enhancements.

rglbegl

At 160mph+, while drafting another car at 6 inches . . . . they are wonderful.

other than that, they are ricer junk

Lancerman360

I agree. The Evo started it and it is supposed to smooth the air flow on the stock evo wing.

If I ever saw stick on shark fins on any other car I would laugh and point.

Black91n/a

They're not useless and they most certainly don't smooth airflow. What they do is cause vorticies (spinning air, sort of like a tornado) which help keep the airflow attached to the surface for longer, which can bring cleaner, higher energy air to a wing as the EVO does, and it can help reduce the low pressure region behind the car for a reduction of pressure drag.

http://pmsc.on.ca/bulletin/2005/JulAug%202005.pdf

rglbegl

^^^^^^^
And at 160mph while drafting, or being drafted, it makes the airflow do what you want it to.

At 65mph freeway speeds they just get you laughed at

Hypertek

iTrader: (3)

black91n/a you the man! thanks for your input im checkin out that pdf
cool someone already did the homework for these on their fc =p
this article is awesome!

heres the mitsubishi documentation on the effects
http://www.mitsubishi-motors.com/cor...004/16E_03.pdf

Icemark

when you drive a box with a horrible Cd like the Evo, you need all the help you can get.

Pretty pointless on a FC through, since its drag is still lower than most modern cars

Hypertek

iTrader: (3)

i made this jpeg from the documentation that black91n/a posted

Your not going to notice a difference with just putting them on, but it could aid to making the rear spoiler more optimized.

really good article though, they even tested their ideas. even the TII hood is iffy.

BFGRX7

iTrader: (2)

rglbegl, the efficiency of an aerofoil is increased and thus works sooner with the introduction of vortex generators.

An aerofoil on a 1620lbs. Cessna 172 (light aircraft) can start creating lift below 60KTS (74.8mph) with the help of these generators.

While I'm not suggesting that the wings on our cars are creating 1680lbs of lift, or for our purposes, downforce, the point is that the use of vortex generators allow the wing to work earlier and can, in fact, start creating high double digit downforce figures at highway speeds and more importantly at track day speeds.

It doesn't take much to change weight distribution on our cars.

~Mike

Black91n/a

Also see http://www.fatcatmotorsports.com/ -> Chassis Set-up -> Aerodynamics articles (zip)

There's a compilation of Aerobytes articles from RaceCar Engineering mostly looking at CFD models of different cars, looking at how the various paramaters affect performance. It's good reading at least to get an idea of how these things might work.

Even if you don't need vortex generators for a wing or spoiler, it may very well be able to reduce drag ever so slightly, and that picture shows that there is flow separation across the hatch (although the spoiler will be effecting that, but then again, many FC's have stock wings which will also affect it).

You don't need to be going a bazillion miles an hour to get downforce or to have aero give a noticable, worthwhile effect, there's autocross cars that generate LOTS of downforce at corner speeds in the 35mph range. It all depends on how you design it. Although the faster you go, the more important aero becomes, and yes, for something like an EVO, being much more vertical, stuff like that will have more effect, but that's not to say that it won't do anything on something sleeker, like an FC, and even if it's got a good Cd, it can always be better.

sharingan 19

iTrader: (16)

Very interesting stuff!

Frostycrowd

iTrader: (9)

They look ugly, but some good information in here. I would myself assume they would have no effect at less then triple digits, but that is an assumption and it seems like some good information proves otherwise

Aiden671

thats only for like drag purist i say..

Hypertek

iTrader: (3)

http://autospeed.com/cms/A_3061/article.html
they tested the roof mounted ones on the roof of a prius with no rear spoiler though.

They did put them on the front underside of the bumper and got some good results though.

They probably wont look too bad if you mount them on the rear windsheild frame black area.. just get some black ones, you wont need to paint em.

Evil Aviator

If you do use them, get the aircraft grade VG's rather than those cheapie plastic ricer knock-offs.

Black91n/a

Aero stuff doesn't just turn on at some given speed, it affects the cars at all speeds, it mearly has a greater influence at higher speeds.

rglbegl

So an aerofoil can START to be effective at 74mph.
Too bad the streets I drive on have a max speed of 70.



As I have said before . . . . . at 160mph+, they can be useful to help direct the air properly. But on the street they are nothing more than ricer jewelry.
If you are gonna put some on a track car, they can help with airflow. But for daily driving they are useless.


I know this kinda goes in the "personal opinion" trash can. But they are worthless and make you look like an idiot ricer.

Black91n/a

No, what he's saying is that the wing can generate enough lift at 74mph to lift the 1620lb aircraft off the ground, in other words it's making more than 1620lbs of lift at that speed. Below that speed it's still making lift, just not as much.

Aero can be quite effective at moderate, street speeds if it's properly designed. A Mod autocross cars can corner at several g's at very low speeds thanks to aero, and they typically corner at aout 35mph or so and top out on a typical course in the 50mph range.

THERE IS NO MAGIC SPEED AT WHICH AERO "TURNS ON". IT WORKS AT ALL SPEEDS. IT MERELY GETS MORE EFFECTIVE AS SPEED INCREASES.

Sure, VG's on a street FC probably won't really make a noticable difference, but that's not to say that they're not doing anything.

drugblock12a

iTrader: (7)

I have seen and studied these on the aircraft I used to work on. They can be used for a few reasons and I don't think my 7 would ever need those. The only major use I ever saw for them was in the front of an intake for a jet engine so it would break up/create a votex before the air hit the fan blades so it could process it better. There are plenty of things you can do that will look better and work better for your dollar. I like to use horsepower and good tires instead of expensive carbon fiber crap that my car doesn't need or want. (we talk)

Evil Aviator

There needs to be sufficient laminar airflow over the surface for aerodynamic devices to work. There is actually a minimum speed at which aerodynamics will not work, but the actual speed depends on a lot of factors.

For example, here are some pictures of aircraft airspeed indicators. Note the wing stall speed markings. If the pilot attempts to fly much below the indicated speeds, the wing will stop working and the airplane will begin to fall out of the air.
http://en.wikipedia.org/wiki/Stall_s...speed.E2.80.9D

Black91n/a

I know, but I was just trying to simplify things for these people who seem to think that you need to be going a bazillion miles an hour for any aero type thing to work. My point being that if they're designed to do so, aero devices can have a substantial impact at quite low speeds and they don't just suddenly "turn on", they come in gradually and progressively as the speeds climb.

CarzArKoo1

20 bucks, try it hehe

Hypertek

iTrader: (3)

these are teh Sard units



http://i193.photobucket.com/albums/z.../IMG_8584r.jpg
of course tho, these cars that are rockin em have high mounted spoilers.

Interesting, but i cant imagine a aftermarket company is going to invest in wind tunnel just for an item that could easily be ripped off. Their units dont seem like they would produce a vertex. unless they are more like roof fins?

Autospeed did a good 4 part article on their own testing and conclusions
http://www.autospeed.com/A_3058/cms/article.html

Even tho the car they tested on was a spoilerless prius, they did say these are worth teh $20 or so bucks you would spend on em, just have to do a little experimenting.

I dont have any plans to mount any tall GT wings.. Just an extended S4 sport spoiler that comes out an extra 1 1/2-2 inches.

Black91n/a

In a lot of ways the Prius testing is better, because it'll better simulate what most people have, that is no high mounted wing. That said, the rear wondow is steeper, so we may be getting laminar flow across the entire hatch, making these useless. Some wool tufting on a spoiler-less FC would show what's what.

HotRodMex

iTrader: (3)

You wouldn't need a wind tunnel. If you have a theory with a solid aerodynamic foundation, all you would need is a consistent car with a consistent driver, do some laps with the car, then do some laps with the car and new hardware.