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.
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)
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):