m3 rear bar myth: let`s finish this!!

[pixelblue]

Originally Posted by Purple Derple

What is an aggressive, fast, tight corner?

against my better judgement but, a corner where you can steer with throttle.

[fourtailpipes]

Originally Posted by pixelblue

against my better judgement but, a corner where you can steer with throttle.

not to start a semantic digression, but isn't that every corner? ceteris paribus, what's going to determine if the swaybar is a significant piece of the equation or just irrelevant (like it is when driving around at 5/10ths)is the G load. throttle steering is a technique applied by the driver at will. the resulting effect of the swaybar may differ slightly, but a G is a G whether its happening on a long fast sweeper or a tight hairpin.

[pixelblue]

Originally Posted by fourtailpipes

not to start a semantic digression, but isn't that every corner? ceteris paribus, what's going to determine if the swaybar is a significant piece of the equation or just irrelevant (like it is when driving around at 5/10ths)is the G load. throttle steering is a technique applied by the driver at will. the resulting effect of the swaybar may differ slightly, but a G is a G whether its happening on a long fast sweeper or a tight hairpin.

I don't know do you use throttle steer for long fast benders too?

[fourtailpipes]

Originally Posted by pixelblue

I don't know do you use throttle steer for long fast benders too?

sometimes. depends on the car and the situation.

[Purple Derple]

Originally Posted by pixelblue

against my better judgement but, a corner where you can steer with throttle.

haha you are the man pixelblue. as you could tell, yes it is bait. By definition a fast corner cannot be tight, and a tight corner cannot be fast. All relative, naturally. As you know, at a given lateral g-force, the speed and radius of a corner are directly related. Increasing radius will allow for an increase in speed. A smaller radius corner, a tight corner, would necessitate a lower speed so that g-force does not exceed grip available. A corner cannot be fast and tight at the same time Q.E.D.

Originally Posted by int2str

A rear swaybar will show it's effect the most on tight turns on mountain roads or other aggressive, fast, tight corners.

[pixelblue]

Originally Posted by fourtailpipes

sometimes. depends on the car and the situation.

well then that would make for one spectacular drift

Originally Posted by Purple Derple

haha you are the man pixelblue. as you could tell, yes it is bait. By definition a fast corner cannot be tight, and a tight corner cannot be fast. All relative, naturally. As you know, at a given lateral g-force, the speed and radius of a corner are directly related. Increasing radius will allow for an increase in speed. A smaller radius corner, a tight corner, would necessitate a lower speed so that g-force does not exceed grip available. A corner cannot be fast and tight at the same time Q.E.D.

purple you are correct, you got me there. got lost in the semantics

[Purple Derple]

Originally Posted by pixelblue

well then that would make for one spectacular drift



purple you are correct, you got me there. got lost in the semantics

Ah you but didn't say it, someone else did.

[int2str]

Originally Posted by Purple Derple

By definition a fast corner cannot be tight, and a tight corner cannot be fast.

Let's not confuse this thread by getting hung up on semantics here.

It probably wasn't the most elegant wording, but I was trying to differentiate a Lombard street type scenario with tight corners that are taken at very low speeds and relatively tight corners that can be attacked with some speed.

Pixels definition is actually pretty good, too.

[Purple Derple]

Originally Posted by AnooooOH

def sounds like everything I`m searching for!

but because if the marketing thing I`d like to hear some opinions!

But imo this should work out:
square tire setup + m3 front AND m3 rear bar = same neutral feeling and more traction

AnooooOH, why don't you spend the money on a track day instead of anti-roll bars? That would definitely make you appreciate your car as it exists now more, and you would have learned something.

[int2str]

Originally Posted by Purple Derple

AnooooOH, why don't you spend the money on a track day instead of anti-roll bars? That would definitely make you appreciate your car as it exists now more, and you would have learned something.

Timely Fifth Gear segment on the topic (starting at 18:20):

[pixelblue]

Originally Posted by int2str

Timely Fifth Gear segment on the topic (starting at 18:20):

that was great! funny how tires were faster than the tune and weird how exhaust had such an impact but I totally agree with the idea of getting coached first. of course there's always exception for the naturally gifted ones

edit:
on second thought her times have little meaningful value since she was a novice. I missed the point, ooops

[AnooooOH]

Originally Posted by fourtailpipes

with those tiny tires in the back, its doubtful that you'll generate enough lateral mechanical grip on that axle to pick up an inside rear tire anyway. you may not run into issues with the diff, but if you don't, it'll only be because you'll be carrying less speed than you could be and therefore loading the axle less.

take the diff out of the equation for a moment... adding a stiffer swaybar to the rear axle while also reducing the rear tire width from 245 to 225 is going to cause a substantial impairment on the grip generated by that axle.

and for what its worth, in modern times, ac schnitzer is kind of a joke. more of an authority on hideous body kits than chassis dynamics.

how can you say that? have you ever driven one of their cars?
I did! They have 25 years experience! The engineering guy is still the same.
They have the best service you can think of!

Since I only know them from bmw meets and so on,
they made me the offer to make a 600km trip to them and they`ll spend a hotel room and show me every corner of their halls.

And yes, I`m not liking most of the body kits too!

Btw. have you ever driven the 225 square setup?
It feels way better than 225/255 that I had before.

Originally Posted by int2str

AnooooOH, I know you're looking for a simple answer, but I don't think there is one.

You say you want "more stability" and don't want to loose "traction". But it's not that easy. Where/when do you want more stability? Autobahn blasting? Fast corners? Slow corners? It all depends...

If you want more "Autobahn" stability, you're probably fine with a conservative alignment. An alignment can make a big difference in how the car feels. For long sweeping Autobahn turns, yes, maybe swaybars would help, but I'm not sure they'd be my first choice.

What about traction? Do you ever loose it? Doesn't sound like you do. I highly doubt that any suspension mod that you've mentioned so far (swaybars or no bars) will make a significant difference for daily driving. A rear swaybar will show it's effect the most on tight turns on mountain roads or other aggressive, fast, tight corners.

Regarding tires:
A square setup is the best choice in my opinion for a good balance and quick turn-in on our cars. Note that "good balance" is not the same as stability. A naturally under-steering car will always feel more stable than a well balanced car that's ready to turn.

If I had to start all over again I'd probably do this (and in this order):
1. Proper tires (Dunlop Star Specs; Michelin PSS etc.); 235 square probably
2. Camber plates and sportier alignment (note that this is for better turn-in; not stability)
3. Springs
4. Front swaybar
5. All 4 rear sub-frame bushings

Note that the swaybar is 2nd to last in that list....
Unless you've already done 1-3, I'm not sure I'd bother at all.

Now again, my goal is a well handling car, not a rail cart

If you're so bent on swaybars and can't make up your mind. Why not get the front first, run that for a while and if you don't like it, add the rear swaybar later down the road. Who knows, you might end up saving a bunch of money that way if you decide the rear bar isn't needed (which most of us think here)...

Thanks for your great answer!

I want a more planted feeling at high speed.
So I want the bouncing to be gone. That`s what I mean with stability.
That`s the biggest problem!

And I want to reach higher speeds on mountain roads,
where I drive every day.

Atm I have eibach springs, but the m dampers doesn`t feel good at all,
so I want to do the whole thing.
coils, bars and bushings! at the same time.

Now do you think what would be my setup?
Sounds like I don`t need bars at all!

And why sould I go for ONLY a front sway?
I think my car rides pretty neutral at the moment.
wouldn`t it be better to change none or both?

Originally Posted by Purple Derple

AnooooOH, why don't you spend the money on a track day instead of anti-roll bars? That would definitely make you appreciate your car as it exists now more, and you would have learned something.

Who told you I am not?

I think this is a pretty good tip.
But the main problem is at high speeds on the autobahn.

And I did several track days.
With the 130i I had before and with the 135i.
I have a real and famous racetrack in front of my door (Oschersleben).
The nordschleife is not too far away. I was there couple of times.
BMW Performance invited me for couple trackdays where I drove their 135i and 335i with a trainer.

So the problem is not that I don`t know how to drive.
I know what is missing to get it better.
But I don`t know what hardware I need to solve the problems.

Originally Posted by int2str

Timely Fifth Gear segment on the topic (starting at 18:20):

[Purple Derple]

Originally Posted by AnooooOH

So the problem is not that I don`t know how to drive.
I know what is missing to get it better.
But I don`t know what hardware I need to solve the problems.

Wise man once said, "driving is like sex; everyone thinks they are great at it."

Why spend money on parts when there is a limit to how fast you can make your car go? Why not spend it on experience because there is no limit to how fast a driver can go?

Running 225s at the back instead of 245s will decrease lateral grip in dry weather. You have changed the balance of the car by lowering grip on the back to match the front. Overall your car will be slower in turns.

If your car is bouncing then your problem is dampers, and probably bushings too.

[AnooooOH]

But I said that I already have some experience with a driving trainer and with tracking?
Of course I can get better! Everyone can! But I`m as good as I need to be.
I`m not a race driver, but I can have fun on a track like I mentioned.
Maybe someone is faster but idc!
I just want to have fun!

Plus driving trainer will be no solution for the bouncing!

Like I said, it have no loss of grip and I`m not slower in corners than before.
I can go threw the same corners and I am def not slower, because the ride feels way better.

Plus I can driver faster threw high speed corners on the autobahn with this setup!
It is very smooth.

[GaryS]

Originally Posted by AnooooOH

I want a more planted feeling at high speed.
So I want the bouncing to be gone. That`s what I mean with stability.
That`s the biggest problem!

And I want to reach higher speeds on mountain roads,
where I drive every day.

Atm I have eibach springs, but the m dampers doesn`t feel good at all,
so I want to do the whole thing.
coils, bars and bushings! at the same time.

To feel more stable and planted and eliminate the bouncing, upgrade the dampers and install all the M3 arms and bushings front and rear and also aftermarket rear toe arms. Leave the rear swaybar alone, and don't waste money on the strut tower brace unless you also get adjustable camber plates and plan on adjusting them. If you have any money left, you might as well get an LSD too.

[AnooooOH]

where can I get aftermarket rear toe arm?

[GaryS]

Originally Posted by AnooooOH

where can I get aftermarket rear toe arm?

http://www.hpashop.com/HP-Autowerks-...2-e9x-nonM.htm

[fourtailpipes]

Originally Posted by AnooooOH

how can you say that? have you ever driven one of their cars?
I did! They have 25 years experience! The engineering guy is still the same.
They have the best service you can think of!

Since I only know them from bmw meets and so on,
they made me the offer to make a 600km trip to them and they`ll spend a hotel room and show me every corner of their halls.

And yes, I`m not liking most of the body kits too!

Btw. have you ever driven the 225 square setup?
It feels way better than 225/255 that I had before.

they may have great service, but 225 square?!? i'm about to purchase my 11th set of tires for this car, and have used several square setups, but none so narrow. currently loving my (spent) 255/265 star specs! i just can't think of a single decent reason to use such narrow tires.

[AnooooOH]

Originally Posted by GaryS

http://www.hpashop.com/HP-Autowerks-...2-e9x-nonM.htm

thank you!!

Originally Posted by fourtailpipes

they may have great service, but 225 square?!? i'm about to purchase my 11th set of tires for this car, and have used several square setups, but none so narrow. currently loving my (spent) 255/265 star specs! i just can't think of a single decent reason to use such narrow tires.

Because of the square setup it`s feel neutral.
I don`t know how to tell in english, but you have the feeling that you are more connected to the car and to the street.
You feel what the car does way better than before.
You feel exactly when your car hits the stability limit and to want point you can push it.

Plus it`s pretty comfortable in cities and on bad roads.

The setup just fits my driving type perfect!

[flinchy]

Originally Posted by AnooooOH

thank you!!

Because of the square setup it`s feel neutral.
I don`t know how to tell in english, but you have the feeling that you are more connected to the car and to the street.
You feel what the car does way better than before.
You feel exactly when your car hits the stability limit and to want point you can push it.

Plus it`s pretty comfortable in cities and on bad roads.

The setup just fits my driving type perfect!

You can fit square 245 pretty easily

225 is WAY too narrow for the rear even in a 128i

[AnooooOH]

Originally Posted by flinchy

You can fit square 245 pretty easily

225 is WAY too narrow for the rear even in a 128i

I had a 130i before I went for the 135i.
So I can def say that you are not right.
There is enough grip in every situation.
It just wouldnt be nice for drag-races.

245 won`t fit with my rims.

[flinchy]

Originally Posted by AnooooOH

I had a 130i before I went for the 135i.
So I can def say that you are not right.
There is enough grip in every situation.
It just wouldnt be nice for drag-races.

245 won`t fit with my rims.

130i owner here, going hard around a corner my back lets go way too easily (245's right now)

i'd definitely nook at a 255/265 rear with 245 front even without any more power

the 225 front is only too small if i go in too hot, but the 245 rear is too small under just about any kind of hard acceleration, even in a straight light the traction control light blinks WAY too freaking often.

so as someone who CURRENTLY drives a 130i, i can definitely say you're not right