[iqraceworks]

On my 03' Mini Cooper S.....a larger aftermarket rear swaybar made a HUGE difference in handling. When pushing the car on curvy roads, it went from crazy understeer.....to a much more neutral type handling. It was a night and day different...bit it's FWD.

On my 07' 335i....I'm running 255 tires in the front, and 275's in the rear. Would I see any benefit on new sway bars for the front and/or rear? The car seems to handle very well already, but I know things can always be improved.

Thoughts?

[Soravia]

NO. They cost too much money or unknown tuning in car front and rear balance.
Just spend money on suspension kits.
Anti sway bars are meant to tune the front and rear cornering balance for under and over steer.
Better to spend that money on actual tuned springs and Dampers

[iqraceworks]

Originally Posted by Soravia

NO. They cost too much money or unknown tuning in car front and rear balance.
Just spend money on suspension kits.
Anti sway bars are meant to tune the front and rear cornering balance for under and over steer.
Better to spend that money on actual tuned springs and Dampers

I already have the Bilstein B12 pro kit suspension with the Eibach Sport springs......just looking to improve handling even more.

[Soravia]

That's where you got it wrong. They are a TINY bit above the factory kit and charge arm and leg.
Their spring rate increase is negligible.
20-30% ? ��
You want 250-400% spring rate increase, with dampers tuned to handle it, so you control without harsh ride.
Harsh ride comes from dampers that are over controlling the springs.
They do that in most kits to make you FEEL you have "sporty" suspension.
Try www.meisterR.com ask for the E90 kit. You'll see real quality suspension without breaking bank. Trust me. They win touring events in UK.
Website for US doesn't list E90 but 1 series. They have E90 if you call or email

[iqraceworks]

Thanks I will check them out. Is there a reason they make suspension for just about every brand of car....but don't list anything for BMW's??

[Soravia]

Originally Posted by iqraceworks

Thanks I will check them out. Is there a reason they make suspension for just about every brand of car....but don't list anything for BMW's??

US Website issues. Check the https://www.meisterr.co.uk/car/suspension/bmw/ . They have the BMWs. Call / email and ask for US guys on E90 suspension.

Only for RWD. https://www.meisterr.co.uk/products/...ies-e90-06-on/

I've been on their CRD kit on my Miata NC for 34k miles, DD. Not a single issue, leak, noise, or ride harshness.
Lighter than OE with billet aluminum for non-strut types.

I'm keeping OE springs with Bilstein HD/B6 for my wagon for ride height. Wagon springs are plenty strong anyway.

If you want to keep Bilstein, PSS-10 is the kit with actually strong springs, for $$$$

[rothwem]

Originally Posted by iqraceworks

I already have the Bilstein B12 pro kit suspension with the Eibach Sport springs......just looking to improve handling even more.

Where do you feel like it falls short? With an '07, and wobbly-ness could be due to worn suspension bushings, not factory spring rates being "too weak".

[mweisdorfer]

Originally Posted by iqraceworks

I already have the Bilstein B12 pro kit suspension with the Eibach Sport springs......just looking to improve handling even more.

If you have the B12 kit, then get the Eibach swaybars to match. They are tuned to the springs in the B12 Kit

[Kevindshea]

Originally Posted by iqraceworks

On my 03' Mini Cooper S.....a larger aftermarket rear swaybar made a HUGE difference in handling. When pushing the car on curvy roads, it went from crazy understeer.....to a much more neutral type handling. It was a night and day different...bit it's FWD.

On my 07' 335i....I'm running 255 tires in the front, and 275's in the rear. Would I see any benefit on new sway bars for the front and/or rear? The car seems to handle very well already, but I know things can always be improved.

Thoughts?

Text book theory and real life experience don’t always agree with sway bars on bmw . Theory is that a fatter front bar increases push. Reality is fatter front bar can increase oversteer on a car that previously pushed. Stiffer front bar reduces camber loss and maintains contact patch , reduces roll and increases turn in. I have a huge hotchkiss front sway bar w stock rear on my e91 RWD 6MT and it’s proper.

[bbnks2]

Originally Posted by Kevindshea

Text book theory and real life experience don’t always agree with sway bars on bmw . Theory is that a fatter front bar increases push. Reality is fatter front bar can increase oversteer on a car that previously pushed. Stiffer front bar reduces camber loss and maintains contact patch , reduces roll and increases turn in. I have a huge hotchkiss front sway bar w stock rear on my e91 RWD 6MT and it’s proper.

Sway bars reducing camber is just a much of a text book theory. To reduce camber loss you would have to actually limit the amount of suspension compression at the limit. Otherwise, the end result is that you still lose the same camber. Takes much more than a small roll bar change. I dont think there is any sway bar big enough to keep you from getting into your bump stops in roll. Might feel better on the street putting around but at the limit not much changes by increasing roll bar stiffness by ~100lb/in. The roll couple distribution does change though.

[Tambohamilton]

Roll stiffness is suspension geometry, CoG location, spring stiffness, sway bar stiffness, and damping...all at the same time. It makes sense that sway bars are the last thing to change in a setup, since they only really do one thing. But also, sort of by definition, they're really just a fine-tuning tool.

So, if you want more roll stiffness, the chances are you need to change your springs. If the end you need more roll stiffness/less cornering grip from is already stiff enough in bump, consider softening the other end instead. If that's not an option, you could fork out $ for fancy dampers, but you'd probably be best off changing the sways at that point.

E9xs generally have a big bar on the front, and pathetic one on the back. This is mirrored by the spring setup (soft at the front, firm at the back), so the roll stiffness at each end is vaguely similar (maybe).

Adding bar at the front does make them feel much more direct and sporty, giving the impression of better handling when you're not using all of the available grip...but when pushed, the front will push more, guaranteed.

Adding bar at the rear is a band-aid for the generally lower levels of grip at the front; you're removing grip from the good end to help/match the bad end, rather than fixing the bad end. But if you need/want to do it, go for it, but there are other things that you probably should do first, which are more important.

Having said all that spew about how things 'should' be done, the first thing I did after new bushings was an E93 M3 rear sway on my E91, and I'm pretty happy with this wrong decision Do what makes you happy.

[Kevindshea]

Originally Posted by bbnks2

Sway bars reducing camber is just a much of a text book theory. To reduce camber loss you would have to actually limit the amount of suspension compression at the limit. Otherwise, the end result is that you still lose the same camber. Takes much more than a small roll bar change. I dont think there is any sway bar big enough to keep you from getting into your bump stops in roll. Might feel better on the street putting around but at the limit not much changes by increasing roll bar stiffness by ~100lb/in. The roll couple distribution does change though.

I know that a lot of RWD bmw track guys (e46 /e90) with huge money builds often prefer the results they get from running the biggest front bar avail set to full stiff along with a stock rear bar .
Wouldn’t camber loss also be effected by the amount of suspension droop on the unloaded side- I would think that’s where you would get most of your benefits in reduced camber loss from ? Stiffer sway bar reducing body roll and thus protecting camber angle on the louded side even if it is already at full compression ?

[Kevindshea]

“ .but when pushed, the front will push more, guaranteed”
Is this from actual track experience or from text book theory? Not trying to be rude , just asking . Because I don’t pretend to be a track rat. I have only a little experience in the track but a decent amount of experience at auto cross . But I do like to talk to experienced track guys about set up . And surprisingly it is common practice for e46 m3 guys among others to run the stiffest possible bar up front and stock in the rear even if it means leaving the matched “upgraded” bar on the shelf in the garage .

[Tambohamilton]

Indirect track experience, yes. I mechanic for a team who run a 325i at the nurburgring in the VLN series. Setup on the car is just a constant balancing act, trying to get as much front grip as possible, without demolishing front tyres (4h races).

I have no experience of it, but doesn't the e46 have a comparatively flexible chassis? I think that's why e46 guys run firm front bars; they can't transfer roll stiffness from the rear in the same way an e9x can, and they may as well keep grip in the back end for low gear corner exit (and open diff). Also if the e46 rear bars are like the e9x rear bars, the M3 variety is a huge step up in stiffness from the non-m bar!

[bbnks2]

Originally Posted by Kevindshea

I know that a lot of RWD bmw track guys (e46 /e90) with huge money builds often prefer the results they get from running the biggest front bar avail set to full stiff along with a stock rear bar .
Wouldn’t camber loss also be effected by the amount of suspension droop on the unloaded side- I would think that’s where you would get most of your benefits in reduced camber loss from ? Stiffer sway bar reducing body roll and thus protecting camber angle on the louded side even if it is already at full compression ?

I was not saying that a bigger sway bar should not be used or cannot be better. I was just pointing out that a sway bar reducing camber change at the limit of lateral grip is just as much of a textbook theory as a sway bar increasing understeer. You're likely down on the bump stop a lot more than you realize. Also, a sway bar unloads the inside wheel more which is why you see rwd owners hesitant to add a stiffer rear bar. Torque biasing system can be overwhelmed and cause the inside wheel to spin which is wasted time.