Are the VG's from Rexpeed any good? You can get one from them for only $115.00 (Painted Vortex Generator)

 

thanks guys any pix?

 

Ouch, what was it attached with?

 

yes and i use 3m double sided tape still didn't hold at all so save your money for something else

 

3m double sided tape

 

I like them, but wont do any noticable difference in performance or feel. Wont matter which evo you have from 1- X.

 

Mitsu did wind-tunnel testing with a VG on the Evo X??

Anywho, I'm sure Mitsu Japan knows best.. but I'd also hope that Mitsu UK / Colt Car Co and WRC Developments that designed the FQ400 weren't just adding aero do-dads for the hell of it. 2 of the guys from WRC Dev worked for both Prodrive and the Subaru WRC program.

Wind tunnel data on the FQ400 would be nice, but all I found was this info from the Mitsu UK / WRC Dev press pack (PDF LINK)..
Hopefully they weren't just making random crap up to sell an already limited, sold-out special edition X. I really don't see a motive.. but who knows?

And some food for thought.. in Mitsu's published wind-tunnel data that you mentioned, half the dang article is about their underfloor air-guides.. which are $900, not a USDM option at all, and only available if you import them from Japan.

 

For clarity's sake:

No. At least, not that I know of or have seen data from. What I've seen are the wind-tunnel data of the as-sold body and it clearly shows no need for VGs.

 

Well that sucks

I think APR sells them but they are more than double the price

 

^^ Yeah, the APR is probably the nicest one being made, but it's around $300.

It's weird.. I'm not all that crazy about the look of a VG on the X, and I'm starting to believe Iowa that we probably don't need them.. but for same strange reason, I still kinda want one. Lol.

Kinda wonder if it has enough effect on drag to effect MPG either negatively or positively?

 

That depends, of course, on where you put them. On top of the roof, such that the turbulence is mostly on top of the trunk, they will reduce lift but definitely increase drag. On the back edge of the trunk, in contrast, they will do nothing for lift, but might reduce drag.

The other issue is whether VGs will help or hurt the functioning of the rear wing. If you have some aftermarket wing at least 10-12" over the trunk surface, then have at it. But with either of the OE wings on an Evo X, VGs up on the roof will almost definitely cause the wing to cease doing what it's supposed to, and just add drag, instead. That's the difference between the X and previous Evos. The previous roofline, with the steeper rear window, made it hard for the OE wing to function. In those cases, VGs helped the wing to work. An Evo X's wing needs no help because of the slope to the rear edge of the roof and the softer angle of the rear window.

 

stickers add more HP than the VG does.

 

But what if you add stickers to the VG??


( Photo by BKevoX - https://www.evolutionm.net/forums/ev...oto-shoot.html )


Also, I guess you can actually buy OEM FQ vortex generators..

http://www.fqperformance.com/shop/pr...oducts_id=1791

 

The OEM VG works, but you all seem to have the wrong end of the stick. Vortex Generators are drag reduction devices, they are not for downforce!

The OEM device has offset fins, to help with the production of said Vortex' ...... other the ARP VG has straight veins, so I suspect that it is not so effective.

 

If you want to be technical, the function of a VG is neither to produce downforce or to reduce drag. The function of a VG is to maintain clean airflow over a long surface. (Without help, airflow across a long surface will break up terribly.) Sometimes the cleaner airflow reduces drag. Sometimes the cleaner airflow reduces lift. And sometimes the cleaner airflow allows a downstream deflector (such as a flap on a plane's wing or the wing on the back of a car) to work better.

In the case of an older Evo, the VGs on the roof were there to keep the airflow clean over the trunk. This reduced lift from the trunk and made the wing work better. In the case of an Evo X, no VGs are needed because the flow of air across the trunk is not breaking up and needs no help.

With regard to drag, please note that VGs, themselves, always add drag. There is never a free lunch. In some cases, yes, the downstream gains outweigh the immediate effect of the VGs, so total drag might go down. But often you are trading drag for some other benefit, which is usually a gain in the effectiveness of some deflector. The upshot, with regard to drag is this: If your car doesn't need VGs for some other purpose, then you don't want them. Before you put VGs on the roof of an X, ask yourself what you hope to gain from then.