Why the 135 understeer bias is so unnecessary...

[Devon K]

Everyone has been saying that the inherent understeer is needed for safety reasons, so the novice driver or the non-enthusiast doesn't spin themselves into a dangerous situation. But I'd argue that this explanation is now irrelevant, given all the electronic nannies on this car (TC, DSC, etc). These would catch any oversteer in plenty of time to prevent problems - so why not leave the neutral tuning intact for the enthusiast who wants to turn off the nannies and have a little fun? The mere act of intentionally turning off the DSC etc. should absolve BMW of any liability for the consequences....

This would be the perfect, best-of-both-worlds solution - safety for the masses, neutral at-the-limit fun for the enthusiast/weekend tracker.

[BForbes]

I wish everyone would SHUT THE HELL UP about the understeer for just a few minutes. If this car was 100% perfect there would be no need for an //M or Tii or whatever. BMW allegedly expects the 135i to account for a smidge over half of the 1 series sales. Theres gonna be a lot of idiots behind the wheel or these things. Anyhow, I believe it is very evident that they are working on a more FOCUSED MACHINE to ''top'' the 135i. If this bothers you so much then wait for it.

[Sigma]

Originally Posted by Devon K

The mere act of intentionally turning off the DSC etc. should absolve BMW of any liability for the consequences....

And the mere act (or lack thereof) of not bucking your seatbelt should absolve an automaker of liability if you get thrown from your car in an accident, but that's simply not the case. Hell, there have been cases where a driver was drunk, unbuckled and speeding when in an accident and the automakers still lost the case.

[JO3]

Just get 225 or 235 tires up front, and a stiffer rear sway bar and call it a day. Understeer cured.

[ZAMIRZ]

Originally Posted by onehots2k

I wish everyone would SHUT THE HELL UP about the understeer for just a few minutes. If this car was 100% perfect there would be no need for an //M or Tii or whatever. BMW allegedly expects the 135i to account for a smidge over half of the 1 series sales. Theres gonna be a lot of idiots behind the wheel or these things. Anyhow, I believe it is very evident that they are working on a more FOCUSED MACHINE to ''top'' the 135i. If this bothers you so much then wait for it.

[ChrisK]

Everyone seems to be forgetting that the 1 series is an enthusiasts car, right?

Enthusiasts like to mod their cars. What fun would it be if the car was perfect right our of the gate. Dinian, BMW, and others will fill the gap. aka understeer, fog lights, LSD, etc.

[Crashspeeder]

Originally Posted by joe

Just get 225 or 235 tires up front, and a stiffer rear sway bar and call it a day. Understeer cured.

is it strictly a matter of the tires not biting enough due to surface area? I'd expect the sway bar to make a bit of a difference tho.

[TGrits10]

Originally Posted by Devon K

I'd argue that this explanation is now irrelevant, given all the electronic nannies on this car (TC, DSC, etc). These would catch any oversteer in plenty of time to prevent problems

When I read this, I couldn't help thinking of modern jet fighters, which employ this principle to great effect by being inherently unstable (oversteer, woohoo!!) for maximum maneuverability. Powerful computers (electronic nannies?) take care of keeping things on the right path...fwiw, I dunno.

[josh]

Is it possible that it would have cost them more to balance it and they left the understeer as a cost-saving measure?

[Crashspeeder]

Originally Posted by josh

Is it possible that it would have cost them more to balance it and they left the understeer as a cost-saving measure?

that almost sounds like "it's not a bug, it's a feature!"

[TGrits10]

Originally Posted by josh

Is it possible that it would have cost them more to balance it and they left the understeer as a cost-saving measure?

Not with 50/50 weight distribution. If you can't balance that, you should just kill yourself and get it over with. This is BMW we're talking about, they know what they're doing, it handles that way because they want it that way.

[Propagator]

Originally Posted by chriskurn

Everyone seems to be forgetting that the 1 series is an enthusiasts car, right?

Enthusiasts like to mod their cars. What fun would it be if the car was perfect right our of the gate. Dinian, BMW, and others will fill the gap. aka understeer, fog lights, LSD, etc.

Oh come on man, you know that's bull. Are we talking about a cheap stripped down tuner car here?

I think Devon raised a good point. An FR car with that much power should in principal be made very neutral with the ability to power steer. This would make auto journalists worship the car all over the world. Then they can make the car understeer with VDC programming. Sounds logical to me.

But I do think it's not such a big deal, especially compared to the lack of 260HP NA engine and other more important things that BMW skipped. The car has a very good chassis balance to play with, and minor suspension mod is by far the easist mod you can do. Well, next to a reflash I guess.

[mikeo]

There is no way that BMW AG's lawyers will let ANY current production car, Motorsport or standard, leave the factories that does not have understeer built-in.

[Devon K]

Originally Posted by Sigma

And the mere act (or lack thereof) of not bucking your seatbelt should absolve an automaker of liability if you get thrown from your car in an accident, but that's simply not the case. Hell, there have been cases where a driver was drunk, unbuckled and speeding when in an accident and the automakers still lost the case.

This analogy blows - the two are simply not comparable. Driving without a seatbelt requires no additional action on your part - just get in the car and drive, voila! - no seatbelt in use. However DSC on is the default setting and has to be actively turned off. I'm no lawyer (thank God) but I have to think that legally the two are very distinct from a liability standpoint.

[Sigma]

Originally Posted by Devon K

This analogy blows - the two are simply not comparable. Driving without a seatbelt requires no additional action on your part - just get in the car and drive, voila! - no seatbelt in use. However DSC on is the default setting and has to be actively turned off. I'm no lawyer (thank God) but I have to think that legally the two are very distinct from a liability standpoint.

My point wasn't that it was a comparable analogy -- you will note that I specifically mentioned that it was a lack of an action in the seatbelt situation. My point was that, just because common sense dictates that someone shouldn't be liable for something, doesn't necessarily make it so.

Unfortunately there's a distinct lack of common sense within the judicial system. Automakers will rarely win a case that is brought up against them by an individual, no matter how obviously right they may be. Juries are very sympathetic to a grieving family or a maimed individual and "it's just a few million" to a massive corporation. As a result, you can't simply an engineer a car with something with an option to keep the car safe, you have to engineer the car to be as absolutely safe as you can make it, so that you can avoid (or at least minimize) the cases of people turning DSC off and then suing you when they get into an accident because it will happen. That's precisely why in most applications you can't actually turn DSC completely off. Because the simple act of the driver consciously pressing that button isn't going to help the automaker in court at all if/when there's an accident. So, even when it's "off" it's still making sure you don't get too messed up before stepping in.

You see the same thing in the railroad industry (I've been an engineer in both industries, so I've seen all this and had to attempt to deal with it all first-hand). No matter how much active crossing warnings on, no matter how difficult to get around the gates you make it, no matter how loud and bright you make the warnings, people will still find ways around gates and attempt to beat the train. And hundreds of people a year won't make it. And every single one will receive a settlement from the railroad. History has shown that juries will almost always find against the railroad. And even if they do win, the negative press costs exponentially more than whatever they avoided by not just paying them off to begin with.

Besides, even if we were in a perfect world where juries used common sense, simply pressing a button still doesn't absolve anyone of liability. There's a whole lot of legal precedent out there on the subject. You can't even begin to argue that liability was absolved unless you can prove that the person was making an educated decision when they decided to press that button. Turning off DSC and accepting the potential hazards of doing so, are 2 seperate acts. That would mean that when you press that button a screen pops up with a warning telling you that pushing the button can cause a potentially more hazardous driving experience (which of course would have to happen when the car was stopped if you were expected to actually read it) and you would have to accept it.

[Ryephile]

"...it depends..."

The understeer reported by media may be a few things:
*the runflat tires are terrible
*the staggered tire sizes reduce front end grip
*the drivers lack finesse/skill to drive the car through the corner with a good line
*the suspension tuning is setup for understeer

Let's address the first one with some alternate perspective. I bought an '07 Cooper S. I put on 215 wide summer street tires. It understeered lots. I went to the racetrack and put on a set of 205 wide Hoosiers, and the car was perfectly neutral. I was able to induce lift-oversteer at will, understeer if I went into a corner too hot and stayed on the throttle, and neutral if I nailed the line correctly.

The second case is easy; a smaller footprint tire will reduce your mechanical grip! Putting the same 245/35-18 on the front as is standard on the rear would give equal tire grip per axle, especially if the car has a 50/50 distribution like the 1-er. This is of course disregarding roll-centers.

The third case, well, lets just say that media personnel may be enthusiasts, but that doesn't mean they are trained professional drivers!

The last case isn't as easy. Given the same tire, we can tune the suspension to be more neutral. Driver preferences and skill will have an impact on how the setup is done. Essentially, you want to make the rear end firmer and the front end softer. This can be done with a stiffer rear spring or stiffer rear anti-sway-bar to name the obvious ones. I'm not going to get into the specifics right now, but there's a time and place for each tweak.

If I was to make an off-the-cuff recommendation based on the [sometimes wrong] perspective of the media, I'd put the same size tire in front as what's in the rear, install stiffer rear springs along with firmer rear dampers and leave the front end and all the anti-roll-bars alone.

Cheers,
Ryan

[mikeo]

Ryan,

I agree with everything you propose, except my preference would be to leave the rear suspension alone, go with the 245 tires in front, as you said (on 8.5" wheels I'd hope), and add fixed or adjustable front camber plates to dial in what BMW MacPherason strut cars love--negative camber. If that didn't make the car neutral, then would come the aftermarket sways.

It would be important to do these thinga one at a time for best overall results.

[dna550]

Passive Restraint Systems, Supplemental Restraint Systems, read Air Bags were mandated because drivers and passengers did not buckle-up their seat belts. Then it became the law to wear your seat belt.

The M Series have the stiffer suspension that enthusiasts are looking for. Most auto shoppers choose comfort, convenience and luxury over track-ready options.

The tii Concept points the way for the 1 Coupe that will perform better on the track. If you track your car regularly, however, you are still going to want negative camber up front, special tires, brakes, etc.

This is a good thing since the more time you spend on the track the better your skills will be at driving a car with a wider range of steering options and the potential for more oversteer.

At a recent BMW perfromance Driving Experience event I drove the 335i with sport suspension on an autocross course, back-to-back with a variety of M cars [Z4 Coupe, M5 & M6]. The 335i just did not have the suspension stiffness, nor the Z-rated non-run flat tires, that the M cars had.

It was a softy, just like the 135i will be until the tii or Club Sport version of the 1 Coupe is offered by BMW.

Of course you can modify the standard 135i with performance parts, but it would be nice to have the BMW factory mods offered with a BMW 4 yr/50,000 mile warranty and the benefit of their suspension tuning experiments on the Nordschleife.

Originally Posted by Sigma

And the mere act (or lack thereof) of not bucking your seatbelt should absolve an automaker of liability if you get thrown from your car in an accident, but that's simply not the case. Hell, there have been cases where a driver was drunk, unbuckled and speeding when in an accident and the automakers still lost the case.

[ppDoc]

you do know that you can induce oversteer with all that torque available to you

[mikeo]

Hanging the tail out with throttle is not the fastest way around a track--looks cool--just not fast.

[Crashspeeder]

i hate to sound horribly noobish but as far as I'm concerned my 325Ci ZSP understeers as well. However as soon as I let go of the throttle a touch it immediately starts to steer into the corner, sometimes feeling like it'll quickly oversteer and spin (with DSC off of course) depending on the curve and my speed. I'm sure the people driving these things know something about driving around a track but I can't believe the 135 will track worse than a 325. Is it just me?

[Ryephile]

Originally Posted by mikeo

Ryan,

I agree with everything you propose, except my preference would be to leave the rear suspension alone, go with the 245 tires in front, as you said (on 8.5" wheels I'd hope), and add fixed or adjustable front camber plates to dial in what BMW MacPherason strut cars love--negative camber. If that didn't make the car neutral, then would come the aftermarket sways.

It would be important to do these thinga one at a time for best overall results.

I think we're on the same page basically. Yes, adding front camber would add bite in the corners assuming that there isn't enough in the factory alignment [which there probably isn't!]. Also, yes, keeping tire size on an appropriate wheel width is important. It'd be interesting to see if the rear wheels are a direct fit in front w/out messing with scrub radius too much.

Cheers,
Ryan