Does the BMW Performance Rear Spoiler provide any aerodynamic benefit?

[jkp1187]

Just what the subject line says - does the OEM rear spoiler on the 135i (or the aftermarket one here, which appears to be similar: http://www.1addicts.com/forums/showthread.php?t=232020 ) have a real performance impact, or is it purely cosmetic.

It's usually my belief that these sorts of spoilers are just for looks and at best have no positive impact (and at worst have a negative one.) But what do I know?

Any engineers out there have a more educated opinion on the subject?

Thanks.

[mugennosora]

unless you're driving like 100 mph i don't think it's going to do anything it's just for looks

[993 911]

Not going to effect anything you feel on the street. Don't buy it for the benefits, don't stress about the downsides. It's all visual.

[italiantank26]

if i'm doing 130 on the highway would it make my car feel more stable than without one?

[1013mm]

Originally Posted by italiantank26

if i'm doing 130 on the highway would it make my car feel more stable than without one?

99% of the time you wont be doing that anyway.

[mugennosora]

^ that and yes you'll have a little more down force...so little if you hit a bump you still are going to fly..

[AtomiK]

Originally Posted by italiantank26

if i'm doing 130 on the highway would it make my car feel more stable than without one?

Not to mention you probably shouldn't be doing 130 mph on a public road.

[Call]

It helps to even out the aerodynamic interference my fat ass adds

Seriously, at 130 it will have no effect other than wiping the smile off the guys you pass

I'm sorry...it must be the mood I'm in at the moment

Call

[jkp1187]

Speaking theoretically - does it actually provide any benefit even at illegal speeds?

I'm just wondering because the way it kind of directs the air up, it looks like it would just generate more eddies behind the car, and therefore more drag. (Again - what do I know? Not an engineer here.)

[mugennosora]

no
wings don't have down force at legal speed, 55 mph

[jkp1187]

Originally Posted by mugennosora

no
wings don't have down force at legal speed, 55 mph

Yes, but at illegal speeds? At 130, even?

[1013mm]

probably a little. any speed that is too fast will rip the tail from your trunk hood.

[mugennosora]

Originally Posted by jkp1187

Yes, but at illegal speeds? At 130, even?

at 130 you'll for sure get some down force to keep the butt down. but it's function compare to zero lift...it's really like not there at all.

so to sum it up our performence spoiler.......does you jack when it comes to driving......but worth every penny when it comes to enhancing the look.

[Carpimp]

I´m no expert, but when i ordered my 135i. I tried my best to get it without the standard "lip", but the answer i got was that the would not remove it.
Germany said that it had to be there, so it has to have some use except look.
Do you guys remember the first Audi TT??? Audi recalled them to add a spoiler to it because it lost traction in high speeds when you started to brake.
And i for one belive that BMW knows what there doing.
I now have the carbonfiber performance wing, and i think it does something.
Anyway, it looks so good i dont care if it does anything except enhance the look.

(Sorry if i spelled something wrong).

Cheers, Morgan.

[esses]

I haven't noticed a difference at 130+ with stock, performance, or without.

[jeremyc74]

Originally Posted by Carpimp

Do you guys remember the first Audi TT??? Audi recalled them to add a spoiler to it because it lost traction in high speeds when you started to brake.
And i for one belive that BMW knows what there doing.
I now have the carbonfiber performance wing, and i think it does something.
Anyway, it looks so good i dont care if it does anything except enhance the look.

(Sorry if i spelled something wrong).

Cheers, Morgan.

The TT was the first thing I thought of as well. I remember when they did that.

IMO the factory spoiler on the 135i is too small to do anything for the styling, so there HAD to be some purpose for the additional cost other than looks.

[amsfoto]

Seeing as how flimsy the performance spoiler is, I seriously doubt it has any real effect on aerodynamics, but I'm no engineer. I was a bit surprised at how flexible and light it was.

[arok]

it shoudl, but it should be minimal...

now if you had a huge wing like my old STi, it DEFINITELY helped plant the car at 100+ .

the truth is, you probably won't feel it...

[IceDragon2000]

Well, I live in Germany and 130+ is normal autobahn driving where I am at here. Would it effect my LEGAL speed? Cause at 136 Mph (Cruise Control set, not GPS Speed) I'm getting around 20 mpg and like to cruise at that speed. So having more stability would be a plus.

[AlienDNA]

No idea if it provides actual aerodynamic benefits, but it will move you out of Stock class for Solo II, if your club uses SCCA rules and has people that like to protest that sort of thing...

[TT1351]

I think the real answer lies with an expert in aerodynmics. All to often everyones opinions are thrown into the mix with no basis for these opinions other then this is what they think. I would be willing to bet it adds down force, and the down force increases with speed. Its flexibility and apparent flimseyness disappears once properly installed. Just my two cents.
Fran

[scorcherjf]

The Koenigsegg CCX on Top Gear shaved almost 3 seconds off its lap time with the top gear wing!