135i functional downforce?

[Legion5]

I was going over the technical data that was recently released for the 135i and discovered that the version with a so called "aerodynamic body kit" from BMW's M division was actually a huge 12% LESS aerodynamic than the normal version. (135i vs 128i)

To be honest that number is just sad, and not being some one who researches BMW's all day, I'm posing a question to all those who do.

Is it BMW's style to have functional downforce on it's M models? If the car is 12% slower through the air, then it stands to reason that it should produce 12% more downforce (400lbs) at speed. Will this be the case here, or is BMW all "for pretend" and not all "for real"?

[imported_MPower]

I do not understand what you mean by 12% less aerodynamic. Remember that drag co-efficient does not encapsulate aerodynamics as a whole.

[ichiban]

Unless your going 80+ you wont really feel a difference. And it would make sense to have the m models to have more down force because these are the models that will most likely see track days, thus having more downforce will give the driver better road feel.

[ppDoc]

unless u use it in a track (or the autobahn) u won't see any difference whatsoever.

[atr_hugo]

The biggest aero issue with the 1er can be seen at the front of the car - especially the 135. Look how much tire is exposed in the front view. And it ain't functional downforce - that is staright up fuel economy robbing drag. ; -)

As far as the small wickerbill/Gurney-flap on the rear deck-lid is concerned, it's aero contribution will only be significant at extra-legal speeds (those beyond 100 mph).

[Legion5]

Originally Posted by MPower

I do not understand what you mean by 12% less aerodynamic. Remember that drag co-efficient does not encapsulate aerodynamics as a whole.

You're right I should have used the term "stream lined".

Originally Posted by ichiban

Unless your going 80+ you wont really feel a difference.

Actually now that I look it up, at 50mph it will rob you of 6hp more than you are already losing. At 70mph it will rob you of about 14 and it just gets worse and worse from there.

And it would make sense to have the m models to have more down force because these are the models that will most likely see track days, thus having more downforce will give the driver better road feel.

Right, but does the down force actually exist, or is it akin to most spoilers these days which tend to do nothing (evos and STI's being the exception)?

[BMWeber]

Originally Posted by Legion5

You're right I should have used the term "stream lined".



Actually now that I look it up, at 50mph it will rob you of 6hp more than you are already losing. At 70mph it will rob you of about 14 and it just gets worse and worse from there.




Right, but does the down force actually exist, or is it akin to most spoilers these days which tend to do nothing (evos and STI's being the exception)?

read up a bit more on aerodynamics CD is a very meaningless number by itself. and that .03 difference could just be from the tire size difference.

[rbehny]

If you're really worried about .03 I hope you'll never open your windows or sunroof at speed.

[spudw]

When it comes to performance, I'd rather have a higher CD and higher downforce. Unless you're going for time at the Brickyard or at Monza, a marginally higher CD means nothing. A little extra downforce, however, is always nice to have on a twisty road...

But it's all marginal really. If it's a real track car, it'll get modded anyway. Take the gurney flap off, lower the ride height, tape up the seams and you'll lower the CD. But we're not talking about 1,200 pounds of downforce like an F1 car. It's really marginal on a road car...

Anyway, I'm generally not concerned with CD and downforce on my drive into the office. Just keepin' it real...

[Legion5]

To answer the questions of the previous two posters I'm not worried about small differences like 14 hp here or 10 there (actually what many sources quote as power lost away from fuel economy and acceleration when the windows are down in a sedan).

What I am worried about it BS engineering, I'd like to see this car as a zippy streamlined thing but actually, not only is it only marginally lighter than the 335i, it's seeming to have more drag than it as well.. (135i that is)

Infinity for example has functional aero kits, that actually reduce the coefficient of drag on their cars, yet their competitor BMW has an aero kit that makes the car seemingly "slower".

So if Infinity can stay away from BS why can't BMW do the same?

To me this is cutting down a car I actually like and it worries me that this is a sign of more things to come from the 1 series that we are just unaware of yet.

Now, if all this extra drag were put to good use, I'd be all for it (most road cars don't nearly have enough down force) unfortunately it's a little hard for me to accept that that's going on. Fatter tires would only contribute 4% to that 12%, and I'm looking to buy a car that is not watered down here...

If I wanted something that looked fast I would buy a set of "rocket" fins and tape them to my sport coat. I'd also get a scale model of a Veryon and look at it all day instead of going to a track.

So yes, I keep finding out all of these nasty little things about the 1 series and all I have to say is that I'm not here to get a car who's whole purpose is to be slotted below the 3.

I'm seeking something that represents quality.

[ShifterKart]

It is simple, you can't create downforce without creating drag. Look at Formula 1 cars, drag coefficients are well over 1.0 but they stick like glue. Maybe the Infinity doesn't make as much downforce, maybe they started with a cleaner car??? Some might say if Infinity claims positive downforce increases with positive reduction is drag that is BS Engineering!

[BMWeber]

Originally Posted by Legion5

To answer the questions of the previous two posters I'm not worried about small differences like 14 hp here or 10 there (actually what many sources quote as power lost away from fuel economy and acceleration when the windows are down in a sedan).

What I am worried about it BS engineering, I'd like to see this car as a zippy streamlined thing but actually, not only is it only marginally lighter than the 335i, it's seeming to have more drag than it as well.. (135i that is)

Infinity for example has functional aero kits, that actually reduce the coefficient of drag on their cars, yet their competitor BMW has an aero kit that makes the car seemingly "slower".

So if Infinity can stay away from BS why can't BMW do the same?

To me this is cutting down a car I actually like and it worries me that this is a sign of more things to come from the 1 series that we are just unaware of yet.

Now, if all this extra drag were put to good use, I'd be all for it (most road cars don't nearly have enough down force) unfortunately it's a little hard for me to accept that that's going on. Fatter tires would only contribute 4% to that 12%, and I'm looking to buy a car that is not watered down here...

If I wanted something that looked fast I would buy a set of "rocket" fins and tape them to my sport coat. I'd also get a scale model of a Veryon and look at it all day instead of going to a track.

So yes, I keep finding out all of these nasty little things about the 1 series and all I have to say is that I'm not here to get a car who's whole purpose is to be slotted below the 3.

I'm seeking something that represents quality.

just about the CD: if you compair all the 1 series coupes the M sport package adds no drag. only the 135i M package with larger tires(215/245) has a .33 CD. the 123d and 120d with the M sport and little 205 tires have a CD of .30. do a little research next time and try not to start bashing something you obviously have not researched

[imported_MPower]

Originally Posted by atr_hugo

The biggest aero issue with the 1er can be seen at the front of the car - especially the 135. Look how much tire is exposed in the front view. And it ain't functional downforce - that is staright up fuel economy robbing drag. ; -)

That is a trend that most cars are using now-a-days to add aggression to the design. Personally, I like it and if an F1 car can get around it, a road car certainly will. Again, I think it is comical that some would claim that they would be able to feel the difference in something that contributes such a minute amount to the overall feel and performance of the car.

[jasper]

I share the same concern with Legion5. "Show not go" seems to be industry standard these days. Look at the Mini S with it's fake air intakes, diffuser and useless spoiler. The 1-Series occupies a marketing segment immidiately next to the Mini S. Some concerns I have already are the electronic power steering... also, pics of the bottom of the 135i showed it didn't have a true dual exhaust like the 335i.

[mtw]

I remember reading that one of the reasons that foglights are no available on the 135i is because the revised front air dam is needed to increase airflow to the engine.

So, you can look at it either way...it might increase more drag, but the larger M bumper increases air to the engine which undoubtedly increases power (plus it looks badass as well, which never hurts).

I'm sure Infiniti has some great engineers, but I have faith that the boys in Munich know what they're doing.

[ichiban]

Originally Posted by Jasper

I share the same concern with Legion5. "Show not go" seems to be industry standard these days. Look at the Mini S with it's fake air intakes, diffuser and useless spoiler. The 1-Series occupies a marketing segment immidiately next to the Mini S. Some concerns I have already are the electronic power steering... also, pics of the bottom of the 135i showed it didn't have a true dual exhaust like the 335i.

not having a "true" dual exhaust works to the 1er's advantage as it cuts weight and has the same performance as a dual design. and aftermarket exhausts might cost less.

[321]

Originally Posted by atr_hugo

The biggest aero issue with the 1er can be seen at the front of the car - especially the 135. Look how much tire is exposed in the front view. And it ain't functional downforce - that is staright up fuel economy robbing drag. ; -)

:frown::frown: I noticed this aswell... It blow's some serious goat wang. Where's the BMW efficiency there? I guess they bend over for Bangle.

[ppDoc]

Originally Posted by ichiban

not having a "true" dual exhaust works to the 1er's advantage as it cuts weight and has the same performance as a dual design. and aftermarket exhausts might cost less.

yep expect market price for exhaust to cost half less than a normal catback system for the 335i.

i wonder if replacing the headers might make a performance difference in this car. i have the luxury of living in fla and we have no emissions test here

[BMWeber]

Originally Posted by mtw

I remember reading that one of the reasons that foglights are no available on the 135i is because the revised front air dam is needed to increase airflow to the engine.

So, you can look at it either way...it might increase more drag, but the larger M bumper increases air to the engine which undoubtedly increases power (plus it looks badass as well, which never hurts).

I'm sure Infiniti has some great engineers, but I have faith that the boys in Munich know what they're doing.

it doesn't increase drag but like you say it has some function more air to the engine and some provision for break cooling. But I'll admit it is also there for a more aggressive look.