STi Wing, Aftermarket Wing, or No Spoiler?

Alin

Diehard Car Enthusiast!
I've found some more interesting things:

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Alin

Diehard Car Enthusiast!

Apparently Prodrive has already done some tests!!! found this info on several forums, so it must be true!

Tested at 100mph
Vehicle Setup: Front Lift Rear Lift DragHP
WRX with no wing 59.2 70.0 60.5
WRX with stock wing 71.4 50.7 60.5
WRX with Prodrive wing and no lip 75.0 -10.0 0
WRX with stock wing & Prodrive lip 65.8 51.3 57.7
WRX with Prodrive wing & lip 20.8 21.8 58.7
WRX, prodrive lip/wing, 2cm lower 20.8 14.3 54.5
 
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IGOTASTi

System Operator
Staff member
[MENTION=4241]Smee_STI[/MENTION]

Found it!
 
I wonder how well the S204 wing works. That should be one that Subaru tested a lot too, so maybe it'd be close to as good as the STi spoiler. Also wonder if the roof spoiler would be near as effective with the S204 wing as it is supposed to be with the stock STi wing.

And yeah, where is Alin, dude has straight up evaporated here. Unfortunate, hopefully he is alright.
 

Batmobile_Engage

Squirrel Meat Aficionado.
Staff member
I don't think the roof vane would be effective with the S204 wing. If you see the pics and video of STi wind tunnel testing, you'll see a very accurate flow layer directed on top of the factory wing. The S204 wing looks to be a quite a bit lower and therefore, out of the flow layer.
After seeing STi wind tunnel data, I honestly wonder if the S204 wing does much for actual downforce at all. It might reduce lift by disrupting separation flow, but who knows...

I just don't get it.

That said, I feel that its very likely that Subaru spent the time and money getting it right. Too bad they don't put the same effort into their pistons.
 
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Thanks for the input, guys. I've been considering off and on the last few years on doing an S204 wing (probably one of those replicas that are made, genuine likely isn't cheap) on mine eventually. It'd be one of those things that would be done once I get a decent condition Spec-C trunk (Aluminum, baby). And yeah, everything I've heard says the S204 wing was pretty heavily engineered too.

If I do end up doing that combo (Spec-C trunk & S204 spoiler) I may consider hunting down an adjustable roof spoiler and adjust a degree or so CCW (if facing left side of car) to adjust the flow downwards a bit. Removing the roof spoiler would be an option too, but I don't like the idea of random holes being visible on the car.

Planning on going to school for engineering (no clue which discipline yet, but my inclination would be mechanical, even with the bit of EE training I've received in my Army job) so maybe I'll be able to get better input on this type of thing later on down the years (though an aeronautical guy would be a lot smarter about it). Hopefully start/continue next fall.
 

Grinder34

Track Monkey
Soooooo, I actually have a masters in mechanical engineering with a focus in aerodynamics! Woot! That being said, my sub-focus was hypersonics, and I havent done a single aero "problem" in at least six years.

But, without thinking about it too hard after an evening with beer, the roof vane helps pretty much any wing, as it helps the flow not separate over the roof, filling in the low pressure pocket behind the rear wind screen. But the S204 wing being so low never helped anyone. I haven't seen one up close, but if they were going for function >> forum, it'd be at least a dual-plane wing if not a continuously contoured one. I would doubt that the S204 produces as much downforce as the OEM, but I wouldn't bet much on it either way. Neither of them is THAT effective. The OEM one is designed for no front downforce (lift actually), and for even an extra MPG or too. You know that downforce = drag...it's not 1:1, that's why there are a gajillion different airfoil profiles (link). Most people dont care about downforce on their street car, but they do (somewhat) care about fuel economy. I'm not saying the STI wing isn't good, its definitely better than no wing, but it's almost certainly not optimized for giving you serious downforce, and neither is anything except what's on a WRC car. Even then, WRC cars lose front bumpers regularly, so they balance for sometimes having front aero, and sometimes not.

Greg, as far as practical advice, browse forums....a lot. If some old-timers remember, I ended up getting a CF trunk and APR wing for....well crap, $150? It wouldt've been free, but I was on vacation and had to buy it back from someone. The caveat was that they both were in poor condition, visually. I paid to have both paint-matched and STILL came out <$500 (IIRC) and then sold my OEM trunk/wing for something like $400. CF trunks have a lot more fitment issues than aluminium, but for the price I paid, who can complain. ALSO, the APR 200/300 wings are pretty much universal. While you may have to verify part numbers on APR's website, I think the wing is ALWAYS the same, and the "struts" only have something like four versions. So you can get one off of an S2k forum, off of some american muscle, etc...
 

War_Panda04

STill Plays With Toys!
i would say no.. idk how you would take it off tho if that is what you are asking. looks much better with it on
 

Batmobile_Engage

Squirrel Meat Aficionado.
Staff member
That's a tough one. I imagine that it does help and is not merely cosmetic, but I don't know just yet how to compare the two, as the GD and GR chassis are totally different animals.

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No, I love the way it looks. I was just curious if it had the same downforce effect as the "normal wing". I know nothing about physics but it seems pretty pointless where it is located on the wagon.

I guess i'll just have to find someone that will let me take their STi sedan +120 mph to settle this one.
 

Batmobile_Engage

Squirrel Meat Aficionado.
Staff member
Me being a GD owner and having never driven the GR, take this with a grain of salt...or whatever But I would think the GR might be more prone to unwanted oversteer without the wing. It might not produce much downforce, but it likely reduces lift a.k.a. squirrely rear end at high speeds. If you're cool with how it looks and want to adjust high speed handling, have at it, it's your ride.

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Batmobile_Engage

Squirrel Meat Aficionado.
Staff member
By no means will I ever tell anyone what kind of aero is best. Look at mine :rofl:

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Batmobile_Engage

Squirrel Meat Aficionado.
Staff member
No, I love the way it looks. I was just curious if it had the same downforce effect as the "normal wing". I know nothing about physics but it seems pretty pointless where it is located on the wagon.

Where it is, it was likely placed to break up seperation flows, thereby reducing rear end lift.

Where's [MENTION=652]Grinder34[/MENTION], doesn't he know his fluid dynamics pretty well? :)

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War_Panda04

STill Plays With Toys!
from my understanding of the GD wing it only really functions at 70+mph but if you do suspension upgrades its not entirely necessary. i could be totally off tho grinder would be the one to talk to
 

Batmobile_Engage

Squirrel Meat Aficionado.
Staff member
I think it's also fairly reasonable to say that Subaru did a good deal of testing and design work on the GD wing. I can't imagine they'd just slap something pointless on the hatch and call it a day.

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I've considered removing my 05 sti wing but I've taken the car faster then I should have (younger stupid years) and you can tell it helps plant the rear end of the car making it feel more stable at high speeds. Even at 70 mph you can see tge wing flexing in the rear view mirror making me believe its actually helping out.

My wing will stay on even though I'd love to make tge car wingless and low pro.

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