[kaede]

I'll be slowly converting all the suspension parts on my e90 335i to M3 specs. I already have purchased the front and rear control arms which will be going in soon. I have recently secured a rear e93 M3 sway bar 23.6mm. My question is, if I put in the M3 rear sway bar and currently still have stock 335i front sways, will it ruin the handling characteristics horrendously? I am afraid that it will introduce some crazy oversteer when i corner hard. I don't drive on the track but i do drive spiritedly. EVENTUALLY i'll swap the front as well to the e93 sways. But for the time being, will it be dangerous?!?

Thanks!

[335dFan]

Originally Posted by kaede

I'll be slowly converting all the suspension parts on my e90 335i to M3 specs. I already have purchased the front and rear control arms which will be going in soon. I have recently secured a rear e93 M3 sway bar 23.6mm. My question is, if I put in the M3 rear sway bar and currently still have stock 335i front sways, will it ruin the handling characteristics horrendously? I am afraid that it will introduce some crazy oversteer when i corner hard. I don't drive on the track but i do drive spiritedly. EVENTUALLY i'll swap the front as well to the e93 sways. But for the time being, will it be dangerous?!?

Thanks!

There is a relationship between the front and rear sways and effect on handling and I had a good web page on that but can't find it. However, what I was also told was it was best not to put the M3 rear sway on unless you were also going to put in a limited slip differential. At least that's what I recall. On my 2011 335d my first goal (now realized) was to put M3 Rear Subframe Bushings, Quaife LSD, and M3 Rear Sway. Other guys on the forum are more knowledgeable; I just implement their good ideas.

[nitehawk]

Yes, that's a bad idea...rear sway with no lsd will turn your car into a 3 wheel wonder. Not to mention, rear sway is only worth installing if you have the rear subframe dropped for other upgrades (ie bushings).

You can however, just install the front sway and see how you like it. Personally, I would start with a good set of coilovers before anything else.

[CJ421]

I'm in agreement that installing the rear sway bar only isn't a good idea. As a matter of fact I can't see installing the rear sway without an LSD, as 335dFan noted. The problem with upgrading the rear sway without an LSD is the rear is not flexible enough to allow consistent power delivery in turns. The stock 'e-diff' has enough trouble doing that as-is.

Originally Posted by nitehawk

You can however, just install the front sway and see how you like it. Personally, I would start with a good set of coilovers before anything else.

+1 upgrade the dampers/springs before sway bars. Sway bars are tuning tools; the net result is added spring rate in turns. After coilovers, you might discover it's stiff enough and upgrading the sways isn't necessary.

[vasillalov]

Sorry for the threadjack, but I am wondering what would be the effects of doing the opposite: LSD but keeping the 335i RSB?

[kaede]

Thanks guys! I guess I'll just hang onto the sway then for the time being then. I do have plans to upgrade to a LSD in the future, I'll hang tight until i assemble all the parts.

Regarding trying out the m3 front sway first, wouldn't that promote even more understeer in the 335i? I drive a couple or MR cars (aw11 and sw20 mr2, lotus elise, and a NSX) and i love how these cars just pivot around the corner with very control'ed oversteer (mr2 being underpowered, lotus crazy handling, the NSX with moderate suspension tune... but still scary sometimes). I am trying to acheive the same with the 335i even though i know it'd be much harder.

Again, i am not tracking, just like to drive spiritedly sometimes and take corners a little faster than the norm. Thanks though guys!

[cvc 22349a]

Originally Posted by vasillalov

Sorry for the threadjack, but I am wondering what would be the effects of doing the opposite: LSD but keeping the 335i RSB?

More grip

[cvc 22349a]

Originally Posted by kaede

Thanks guys! I guess I'll just hang onto the sway then for the time being then. I do have plans to upgrade to a LSD in the future, I'll hang tight until i assemble all the parts.

Regarding trying out the m3 front sway first, wouldn't that promote even more understeer in the 335i? I drive a couple or MR cars (aw11 and sw20 mr2, lotus elise, and a NSX) and i love how these cars just pivot around the corner with very control'ed oversteer (mr2 being underpowered, lotus crazy handling, the NSX with moderate suspension tune... but still scary sometimes). I am trying to acheive the same with the 335i even though i know it'd be much harder.

Again, i am not tracking, just like to drive spiritedly sometimes and take corners a little faster than the norm. Thanks though guys!

Search sway bars in this forum. 6 yrs worth of reading. They're the last thing you should change in your suspension.

[kaede]

Originally Posted by cvc 22349a

Search sway bars in this forum. 6 yrs worth of reading. They're the last thing you should change in your suspension.

I've been doing a lot of reading as well! But not much on just rear sway bars. Usually most people do all the upgrades all at once

An update though, I have acquired BOTH the front and rear e93 m3 sways, my front and rear m3 control arms as well as subframe bushings have arrived and i'll be putting those in diy (maybe i should yet another diy thread) I will first leave out the sways until afterwards. On the list, I am currently hunting for quaife lsd, KWv1, replace tie rod (meyle?), and maybe m3 struct bar. Thanks everyone!

[335dFan]

Originally Posted by cvc 22349a

More grip

I have driven my car only a few hours since I got the Quaife LSD, but can definitely concur with GRIP. Two rainy wet turns at intersections showed me that. Starts to slip, catches itself in controlled way, and hunkers down and applies power to the pavement. More later.

[RimasRS]

Originally Posted by kaede

Thanks guys! I guess I'll just hang onto the sway then for the time being then. I do have plans to upgrade to a LSD in the future, I'll hang tight until i assemble all the parts.

Regarding trying out the m3 front sway first, wouldn't that promote even more understeer in the 335i? I drive a couple or MR cars (aw11 and sw20 mr2, lotus elise, and a NSX) and i love how these cars just pivot around the corner with very control'ed oversteer (mr2 being underpowered, lotus crazy handling, the NSX with moderate suspension tune... but still scary sometimes). I am trying to acheive the same with the 335i even though i know it'd be much harder.

Again, i am not tracking, just like to drive spiritedly sometimes and take corners a little faster than the norm. Thanks though guys!

Front M3 sway bar will increase understeer. As others said buy good shock spring combo first

[fl335i]

I have a OS Giken Diff. Seriously looking do a complete OEM BMW M3 setup under my E90 335i. I love factory parts.

[Casca]

My car is a 325i non-sport e90. I went with ground control coil overs, camber plates and will have all M3 control arms except for a rear megan toe arm. Not going to LSD as there doesn't seem to be a point with so little power.

Will be droping the rear sub-frame and replace all the bushings with M3 as well when I install the arms. Will be going to front M3 sway bars, but am trying to think what to do for the rear sways.

1: Keep the stock 13mm OEM non-sport rear sway bar and just replace end-links and bushings with OEM parts.

2: Keep the stock 13mm OEM non-sport rear sway bar and replace end link with OEM and bushings wit polyurathane bushings http://www.ecstuning.com/BMW-E90-325...Bar/ES2650414/ . By this point I am already about half-way there to ECStunings e93 M3 rear sway kit.

3: Replace rear sway bars with the e93 sway kit
http://www.ecstuning.com/BMW-E90-325...Bar/ES2622885/

Or maybe
4: Hotchkis front and rear kit http://www.amazon.com/Hotchkis-22834...1&s=automotive

What would you guys do? My car already doesn't lean. I do feel what is probably the subframe bushings...going sideways. I do have another car that is way too stiff for rear and that thing just skips around a corner if there are any bumps, which is less than desirable to me.

[cvc 22349a]

^ imo, sell the front M3 sway bar and leave both sway bars oem. You said roll has been negated by the GC suspension. Why add understeer with the front M3 bar or snap oversteer with a large rear bar? I'd just replace the bushings with oem if they're worn.

[Casca]

Originally Posted by cvc 22349a

^ imo, sell the front M3 sway bar and leave both sway bars oem. You said roll has been negated by the GC suspension. Why add understeer with the front M3 bar or snap oversteer with a large rear bar? I'd just replace the bushings with oem if they're worn.

I'm leaning towards a poly bushing and everything else stock for the rear sways and the fronts be the full M3 kit. Just don't see the bushings being worth costing $65. Trying to find other polyurethane options for 13mm sways.