Amazing Wind Tunnel Testing Data on M3 and 335

[rzm3]

Got these from Sport Auto. It's pretty amazing that a magazine would spend the money for these data.

Anyhow it seems that the aerodynamic improvements on the M3 are actually quite significant:

Front Lift @ 124 mph:
335: 42 kg (93 lb)
M3: 10 kg (22 lb)

Rear Lift @ 124 mph:
335: 28 kg (62 lb)
M3: 23 kg (51 lb)

Note: these cars do not have the aerodynamic devices to actually create down force.

It is pretty amazing that M3's front bumper and some lower body work reduced the front lift by 71 lb. Looks like M3's rear spoiler also works.

Also provided is a comparison between 911 S and GT3 RS. To create down force you need real wings, splitters, diffusers, etc.

Why is the Gumpert Apollo so fast? Just check out how much down force it can generate.

Finally, one may ask why not give the 335/M3 more down force? The answer is that down force comes with its price -- drag, which reduces your fuel efficiency. Super car owners don't really care about MPG, but for a regular street car like the M3 it matters a whole lot, especially in this age.

[FStop7]

93 pounds of lift on the front end of a 335i at 124mph... that sounds kind of scary to me. Like a recipe for some serious understeer.

I would love to see some wind tunnel data on the GTR, given it has a very smooth underbody and a petty aggressive front end.

[GewoW]

yeah my ASS that an F430 can create 250kg downforce with its rear diffuser

BS!

Front lip should help on the M3! And the rear "Performance" spoiler should as well! Would love to see some tests with those - oh well.

[rzm3]

Originally Posted by FStop7

93 pounds of lift on the front end of a 335i at 124mph... that sounds kind of scary to me. Like a recipe for some serious understeer.

I would love to see some wind tunnel data on the GTR, given it has a very smooth underbody and a petty aggressive front end.

Originally Posted by GewoW

yeah my ASS that an F430 can create 250kg downforce with its rear diffuser

BS!

Front lip should help on the M3! And the rear "Performance" spoiler should as well! Would love to see some tests with those - oh well.

Here you go guys.

[FStop7]

Originally Posted by GewoW

yeah my ASS that an F430 can create 250kg downforce with its rear diffuser

BS!

Front lip should help on the M3! And the rear "Performance" spoiler should as well! Would love to see some tests with those - oh well.

I doubt an F430 can generate that much downforce (unless it's at 300mph, LOL) but it does generate a lot. It channels air through the car pretty effectively. If you've ever been behind one in the rain, you'll see it can kick up a pretty big rooster tail.

[GewoW]

Originally Posted by rldzhao

Here you go guys.

Amazing! Just a few kilos less than an M3 in the back! That's honestly sick, and a true testament to BMW!

[rzm3]

I can't wait for Sport Auto to test the M3 GTS! 7:45 around the 'ring?

[GewoW]

Originally Posted by rldzhao

I can't wait for Sport Auto to test the M3 GTS! 7:45 around the 'ring?

I don't think it will do much less than that if at all less...depending on tires too. But oh will it be fast!

And if they wind-tunnel test that, oh yiessss

[TheKosherStogie]

thats a great article! i swear i heard bmw people say that the m3 has zero lift thou.

The gumpert is unreal

[FruitCake]

Very interesting to see how the lower air travels underneath the car and how it enters the car's intakes.

[kaykay]

Incredible!

[mrkbbd]

good find

[jml]

Originally Posted by rldzhao

Got these from Sport Auto. It's pretty amazing that a magazine would spend the money for these data.

Dude, you are the man!

And Sport Auto is a damn fine organization, it must cost them a fortune to do these tests. I had a business friend I worked with who used to be the chief engineer for Ford Mo Co, and he said they relied on Sport Auto for objective performance data for their benchmarking and modeling processes.

[adc]

The differences between the M3 and 335i (taking into account the suspension too of course) match exactly what my butt analyzer felt during the 2 euro deliveries on the Autobahn. 335i became skittish at the front after 130-140 mph and the M3 rock solid all the way to the limiter.

This is a great find, thanks!

[Serious]

I would suspect it has more to do with the flat undertray of the m3 vs. the 335i

I doubt the bumper and lip spoiler do much.

Look at the gumpert's picture you can see the diffuser and underbody aero effect as the air exits the vehicle.

[STALKER]

Great thread!!!

Very interesting info.

[ersin]

What's with the drag coefficient of 12:29 for the 911 and 12:34 for the Ferrari? Typo?

I find it interesting how the CdA for the M3, GTR and Ferrari are nearly the same, i.e. same aerodynamic drag.

BMW says the side view mirrors of the M3 create downforce. I wonder how much this adds to decreasing lift?


Cheers.

[rzm3]

Originally Posted by ersin

What's with the drag coefficient of 12:29 for the 911 and 12:34 for the Ferrari? Typo?

I find it interesting how the CdA for the M3, GTR and Ferrari are nearly the same, i.e. same aerodynamic drag.

BMW says the side view mirrors of the M3 create downforce. I wonder how much this adds to decreasing lift?


Cheers.

It's the Google translator...

12:29 = 0.29

[jml]

Originally Posted by ersin

BMW says the side view mirrors of the M3 create downforce. I wonder how much this adds to decreasing lift?

That would explain why the rattle/vibrate like crazy at speed.

[1MOREMOD]

nice bit of info!

[Voltigeur]

Originally Posted by rldzhao

Got these from Sport Auto. It's pretty amazing that a magazine would spend the money for these data.

That's the Germans' obsessive quest for engineering data (why I love German cars) - Sport Auto rocks.

And props to you also for correct use of the plural form for 'data' I'm anal about stuff like that.

[gr8000]

Originally Posted by ersin

BMW says the side view mirrors of the M3 create downforce. I wonder how much this adds to decreasing lift?
Cheers.

I read somewhere each one adds up tp 3kgs downforce (dont ask at what speed - don't know)