Roof spoilers: Eye sore and they suck

[bimmerfan08]

M3 E46
Wind channel
Lift Force at 200 Km/h (160mph) : 18kg (39.6lb) at rear axis
cW Value: 0,32

M3 CSL
Wind channel
Lift Force at 200Km/h (160mph) : -10kg (-22lb) at rear axis
cW Value: 0,33

60lbs of downforce vs. the standard M3 (which also includes front bumper performance) at 160mph is hardly what I would a real performance advantage. The true value of the trunk is that it is made of carbon and the rest is a bonus.

The OE CSL trunk material is a composite, IIRC

[old///MFanatic]

60lbs of downforce vs. the standard M3 (which also includes front bumper performance) at 160mph is hardly what I would a real performance advantage. The true value ofthe trunk is that it is made of carbon and the rest is a bonus.

The point is it’s not purely aesthetics.
Yes the weight savings is another added bonus along with looks. Just to clarify it’s not made of carbon.

[Albino09]

Well it’s been published long ago and it’s not for aesthetics.

M3 E46
Wind channel
Lift Force at 200 Km/h (160mph) : 18kg (39.6lb) at rear axis
cW Value: 0,32

M3 CSL
Wind channel
Lift Force at 200Km/h (160mph) : -10kg (-22lb) at rear axis
cW Value: 0,33

60lbs of downforce vs. the standard M3 (which also includes front bumper performance) at 160mph is hardly what I would a real performance advantage. The true value of the trunk is that it is made of carbon and the rest is a bonus.

[old///MFanatic]

I wouldn't be surprised if the duckbill is purley an aesthetic appearance thing to help justify the MSRP of the CSL over the base M3.

Well it’s been published long ago and it’s not for aesthetics.

[DJAM3]

Depending on the shape of the rear, vortex generators on the roof edge does help keep flow attached at the rear making the rear wing more effective. When I owned my 240z a group of people got access to a wind tunnel and verified this. Looks like what the CSL roof spoiler is trying to do because of the angle of the rear glass. Re-directing the airflow down instead of detaching.

[usdmej]

roof spoilers and vortex generators work when designed to complement a large trunk mounted wing (see EVO 7 and the hawkeye STIs)

its probably safe to say that something like the ACS roof spoiler is a 100% cosmetic mod for our cars

[Estoril]

I wasn’t expecting much downforce from either one of them.

That is a very realistic expectation.

[jpiazzam3]

That spoiler negates any benefits a CSL trunk will give you.

I wasn’t expecting much downforce from either one of them.

[Obioban]

This is embarrassing

[Gearhead55]

Shameful that you guys are forgetting your grand daddy.

You are correct and I am ashamed

[01SG]

Shameful that you guys are forgetting your grand daddy.

[Gearhead55]

My understanding is that they started on the 190E Evo 3 homologation car. There was a rule that the rear wing couldn't obstruct rearward visibility. Mercedes wanted a bigger rear wing, so they obstructed the back window at the window, so that the wing wasn't obstructing any visibility. Fixed.

People liked the look, and here here we are.

I love that solution for the 190E, classic racing outside-of-the-box response to regulations. I laughed out loud the first time I heard it. The window obstruction isn't really a roof spoiler though, I think there must be another genesis of the roof wing concept.

[Arith2]

I have both the roof spoiler and CSL trunk. I love the look. But to each their own.

That spoiler negates any benefits a CSL trunk will give you.

[Obioban]

My understanding is that they started on the 190E Evo 3 homologation car. There was a rule that the rear wing couldn't obstruct rearward visibility. Mercedes wanted a bigger rear wing, so they obstructed the back window at the window, so that the wing wasn't obstructing any visibility. Fixed.

People liked the look, and here here we are.

[jpiazzam3]

I have both the roof spoiler and CSL trunk. I love the look. But to each their own.