Hey everyone,

I decided to put some vortex generators on my 04 WRX sedan...
I decided to go with these:
http://www.vortekz.com/
the website has pretty good pics and directions.

Obviously these are present on the EVO IX and as multiple old
posts on various boards have shown, they perform a similar function as the roof spoiler
on the 06-07's. Basically they cause air to be redirected so as to reduce drag and
flow over large rear spoilers better (and in theory generate a little more downforce?)
So on a WRX sedan with the WRX spoiler, will this actually do anything?
Who the heck knows?

So then why these particular ones? Well, several reasons. If you look at the following research
paper:
http://www.mitsubishi-motors.com/cor...004/16E_03.pdf
then you 'll notice that there are a few key points about functional vortex generators like those found
on the EVO IX.
First of all, the generators should be twice as long as they are tall. The Vortekz generators come fairly
close to meeting this requirement as shown in the pics - they are roughly 2" long x 1" tall. Secondly,
the generators should be ANGLED - in the paper, they talk about angling the center generators 15
degrees to the airflow direction, whereas the outside generators should be close to 0 degrees. You can actually
see this if you look closely at EVO pictures - the built in vortex generators are indeed angled. Achieving this is easily
done with the Vortekz generators and in fact if you look at the website, this is exactly how they recommend
installing the things. Third, the generators should be located about 100mm ahead of the edge of the roof where
it meets the rear windshield. Since you decide where to put these, that should be much of problem either.
Fourth, these are dirt cheap. I got a set (10 generators + 10 3M mounting tape strips + instructions and mounting templates) for like $25.

The closest things I could find to these for the WRX are the standard roof mounted vortex generator "plates"
like those you can find on eBay - you know what I'm talking about... (see the pic in the next post - the fins are not straight, not angled --
apologies to owners of pirated pics). Even the cool roof spoiler with the built
in vortex fins probably functions more as a roof spoiler than a vortex generator.

So here we go - I got the pre-primered Vortekz generators and painted them with Duplicolor spray paint. After about 3 coats of paint,
I put on 3 coats of clear coat and then let them dry completely before sticking them on. In retrospect, I probably should have put them on
so that they hugged the curvature of the rear edge of the roof better.... oh well. They're on now... I'm happy with the way they look so far.

Will they work? Will they do anything? Hard to say. Obviously the original application was on a totally different car with a different body shape.
Can the measurements be translated from EVO to WRX/STI? <shrug> OK, so if they're just for looks, then I'm no worse off than
the standard eBay roof vortex generator "plate".. but at least the potential of functionality is there Oh yeah, if they happen to blow off within 3 years,
Vortekz will give you 5 free replacements provided you pay S&H.

 

first pic is wrx with straight roof fins for comparison (apologies to owner)
other pics of mounted vortekz generators

 

can you do some tests with it? I'd be interested to see if it will actually help push air down the back window straight and possibly increase airflow on the trunk and wing. For one increase flow for the wing to maybe increace performance for the wing when i'm on the track and to blow the dust off the trunk while i drive daily while making the rain go down straight instead of doing that ring movement on the window.

http://autospeed.drive.com.au/A_108674/cms/article.html

and heres an article about the vortexes
http://autospeed.drive.com.au/cms/A_3058/article.html

 

you are crazy!!! if you wanted downforce you should have gone with the 06-07 roof spoiler... compared to the evo vortex generators the subaru wing yield's superior downforce...

if you're into the vortex generator then its cool, but why not get the evo strip instead of all the individual ones?

but, good effort and looks like you did your homework, just definately not my style

 

I can't find the evo windtunnel pictures right now, but ill gaurantee their downforce with the vortex generators is not as good as the 06-07 sti below:

 

sti roof spoiler is a lot more expensive than vortex generators and requires drilling into the pillars. plus they don't fit the GC bodies without modification. I don't remember anyone making a replica and selling it for cheaper than OEM.

by the way, that looks like a drawing and not an actual wind tunnel test photo, but I could be wrong

 

I actually contemplated getting the rear roof spoiler... only there were two things that kinda edged me towards the vortex generators -

1. cost - the only roof spoiler would have been the one with the built in vortex generators, and that's pretty darn expensive (relatively speaking).

2. have to drill into the side pillar. Plus paint matching would probably not have been as easy - I'd prob. have to get it painted and installed by someone else... hey, it already took a lot of testicular fortitude to drill into the freaking side fenders to do the side marker install. I may eventually try this route in the future, but let's see how these things hold up first.

wrxtunerd - I appreciate your posts. Yes I've seen the downforce comparison photo - the STI generated a buttload more downforce than the evo in their article (which I think was in japanese). However, there are two things - I never said anything about doing this mod specifically to generate downforce. Plus I believe you would also need the STI or similar large rally-style wing to take full advantage of either the vortex generator or the roof spoiler. No, my desire was for a cheap alternative that would offer some marginal functionality - I believe that vortex generators also have a benefit of reducing drag (which may also translate into better fuel economy, although I fully have no expectations of this whatsoever). These were so darn cheap that I was like "might as well"...

Daios - thanks for the links - very interesting reading - esp. if you look at parts 2, 3, and 4 of that article. I'm not sure I really want to tape bits of yarn to my rear window and go carting down the freeway with someone trailing behind me taking pictures. Sounds like a good way to attract the popo if you ask me, although the scientific implications are definately intriguing. I don't suppose anyone has a windtunnel they're not using??? Plus I no longer have a stock control vehicle to compare airflow patterns with...