[stressdoc]

Originally Posted by jbass524

yes you can. **********s you're a great help on this forum and this not to say bah to you.

You need to think of your suspension as a complete system and swaybars are an integral part of that. Just changing bars is usually not suggest on the 335 as you're trying to compensate for something the swaybars are probably not the best solution for. As JPslick said "Yes there is too stiff, you can also really screw with the handling negativley if you go about this the wrong way."

Don't expect miracles with just swaybars and don't go too stiff. OEM M3 if you must.

This is all from someone who has gone too stiff and seen lap times go down even though handling at 85% seemed better because of flatness. At 100% it was worse ... but still flat ;-).

IMHO
1. tires or tires and wheels
2 or 3. shocks/springs/coilovers
2 or 3. M3 suspension bits
4. camber plates
5. swaybars if you still feel you need them

+1 Good advice. HPA and GC have packages that are well designed. Do not over kill one item. Suspensions work as systems.

[chaz58]

Sure, if you know what you are doing and why. All things being equal, the front is going to break away before the rear. Depending on what else you have done to the car, that might be a good thing.

Originally Posted by persian54

I agree that having both sways is always better

but I know many who run just front sways on their 335s and have no problem.
i've driven their cars too and they handle quite nice.
Some have coils, some don't.

[DaFish]

Originally Posted by jbass524

You need to think of your suspension as a complete system and swaybars are an integral part of that. Just changing bars is usually not suggest on the 335 as you're trying to compensate for something the swaybars are probably not the best solution for. As JPslick said "Yes there is too stiff, you can also really screw with the handling negativley if you go about this the wrong way."

Don't expect miracles with just swaybars and don't go too stiff. OEM M3 if you must.

This is all from someone who has gone too stiff and seen lap times go down even though handling at 85% seemed better because of flatness. At 100% it was worse ... but still flat ;-).

IMHO
1. tires or tires and wheels
2 or 3. shocks/springs/coilovers
2 or 3. M3 suspension bits
4. camber plates
5. swaybars if you still feel you need them

Hi jbass524. This is one of the best comments/advise I have heard. I have been battling what to do with my 335i for a while - and I posted a thread (which was really a combination of a number of threads from Orb, Mr 5 and lots of others in the know into a summary of actions I though I would take) called: How to remove understeer, keep ride quality and ZSP height? I have a couple of observations:

1) As jbass524 suggests, and I am realizing now with my winter snows on, wheels and tires make a huge difference. IE: My snows are the same size 17" on 8" rims all the way around. (my summers are the 19" stock 335i rims/tires). When I put my snows on (the same size tire on all around the car) the rotates on corners and has WAY more balance than the summers - it is more fun - the car handles more like what a BMW should. There are a few choices for matching wheels and tires up front and rear - Dinan has a set - but be prepared to swap a kidney for them... they are flippin expensive (but I am considering them (I have 2 kidneys)). Or see this thread on some other rims I think would be great:

http://www.e90post.com/forums/showthread.php?t=88930

Light weight rims and tires that are of closer size front/rear than stock work better for handling.

2) Changing the rear sway bar is probably the most expensive labour item you can do because you have to drop the rear subframe (about 5 to 6 hours of labour - search the forum). Many in the forum says you need to do the rear subframe bushings to control the rear end for traction (controls the alignment on the rear wheels better for a better hookup), and it is cost effective to do both at the same time. I would.

Originally Posted by Orb

On the 335i putting a rear sway bar makes a huge differance in how the car behaves and it is all good. Best single upgrade anyone can do. If i could only keep one mod this would be it.

Orb

--------------------------------------------------------------------------------
Last edited by Orb; 09-12-2007 at 11:16 PM.

2b) If you just change the front sway bar only, you make the understeer worse, you must do both (from what I have read) and match both front and rear sways to get the front/rear bias correct. LOTS of people think that the best option for this is the M3 sways - but read this thread sticky - [url]http://www.e90post.com/forums/showthread.php?t=613 for a description of the sway bar bias (and Orb's threads if you are like me and had no idea what a bias is...). Why mess with any other option on the sways than the M3.... they are made for the chassis.

2c) Koni FSD shocks have a great review from Orb as well.... check that out. easy/cheap mod.

3) The m3 bits - front are easy and cheap to do. See Orbs threads on robbing the m3 for parts. Not sure about the camber plates, but I think if you did the sways/m3 bits and larger rims/tires on the front, then you may not need these... IMHO.

4) I think one of the biggest improvements is the Limited Slip Differential (LSD) and think that will be one of my firsts with the larger rims and tires. Sooo many times coming out of a corner the trac control comes on and cuts the fun, or when you turn it off, smokes the tire... gotta fix that.

If you do them all.... you are into $8 to $10k (Canadian $$), and THEN the rims and tires - I think maybe $5 to $8k... still way cheaper than getting an M3, or trading in for an M3..... and then you get all the torque of the 335 too.

This is my route.

[chaz58]

Ah, you listed all of my favorite threads. Some great info in those

One big advantatage with my snows is they weigh a SHOCKING 20lb less per wheel. That is HUGE. I did try rotating my summer staggered tires, still no problems with oversteer and enough clearance up front to run the 255 tires. Something lighter for the summer is certainly on tap to keep those tires on the pavement.

Some of those threads quote 3.5hrs or ~300 for rear swaybar. The quotes I have gotten are a little less than that.

As for other sways: M3 are a probably a good choice, but some people are going to want adjustable ones.

I feel for you on the LSD thing. I almost didn’t buy the car because of that. Fortunately BMW gave me the e-diff and that does the trick surprisingly well Wheel spin isn’t a problem at all, although the DST has to be turned down for it to be effective. That DST is just too intrusive (especially with 60lb run flats).

You (and Orb and Jbass and Stressdoc) have posted some great info here.

Originally Posted by Bobble

...If not you really want to simply lower the center of gravity a bit, stiffen up the chassis some and tame the body lean...

I don't know about lowering. The BMW performance suspension has less than an inch of travel in the front, and 0.5" in the rear. I don't think that is the best option for everyone.

[uberschnell]

Originally Posted by JPSlick

Yes there is too stiff, you can also really screw with the handling negativley if you go about this the wrong way.

I like everyones recommendation of the M3 sways, that seems to be a sound choice.

I swapped out my H&R set with the M3 set and my lap times improved. Softer sways and stronger springs. Learned this the hard way because changing out that rear bar ain't cheap.

[jbass524]

Originally Posted by MteK

I swapped out my H&R set with the M3 set and my lap times improved. Softer sways and stronger springs. Learned this the hard way because changing out that rear bar ain't cheap.

Amen brother. This is a lesson anyone driving their 335 hard should really consider before putting on STIFF bars.

[roamer]

[QUOTE=chaz58;6662994]
I feel for you on the LSD thing. I almost didn’t buy the car because of that. Fortunately BMW gave me the e-diff and that does the trick surprisingly well Wheel spin isn’t a problem at all, although the DST has to be turned down for it to be effective. That DST is just too intrusive (especially with 60lb run flats).

E-diff is NO subsitute for a LSD, it's an electronic bandaid at best, it just keeps all the power from going up in smoke. It does not allow you to modulate power application or maximize torque to each wheel. Combining a LSD with the M3 rear sway is really the biggest improvement you can make in the handling of this car.
Then, sharpen handling with the M3 bits and appropriate dampers and springs for your driving habits. If you can run 255 square or 255/275 in higher powered cars, the tires should match the capability of the chassis. After that, you would need to start changing the essential character of the car through significant weight loss.

Back to the original question though, the most significant tool for controlling roll is going to be springs. Sway bars are meant to supplement springs by allowing more compliant spring rates for better handling (stiffer is better only to a point), not to be the primary control of body roll. I would avoid a significantly stiffer rear without having an LSD. If you have the sports suspension, the difference between the M3 front and sport front sway is not significant, so you can get away with the M3 rear only with a LSD. As for adjustables, they are great if: (1) you track the car at a variety of tracks; and (2) you have the ability to objectively measure the setup to evaluate if the degree of stiffness and relationship between the front and rear stiffness is appropriate; for the street, they are overkill.

[TheAcAvenger]

+ 1001. I've got the M3 bars and like them way more than I expected to

[1qkviper]

I have a 2009 M-Sport with the complete Hotchkis kit (bars and cross brace) and a Quaife LSD. I think, the car is perfect for the street, and I do not plan to do any other suspension mods.

BTW: If you install the rear sway bar at the same time as the LSD it's not that much more to install. Also add 12mm spacers they look great!

[chaz58]

I thought the dimensions of the M3 sways were similar to the H&R. What is the difference between the two?

Originally Posted by MteK

I swapped out my H&R set with the M3 set and my lap times improved. Softer sways and stronger springs. Learned this the hard way because changing out that rear bar ain't cheap.

[chaz58]

You have different priorities and experiences than me, which is cool. discussion makes people think.

I agree, you should do springs first, then sways (not the other way around). As a lowered BMW typically has less than 1” travel in the front, and ½” in the rear – naturally going lower than factory is not going to work for everyone.

Ultimately, sway bars and coil springs are both technically springs, and both affect body roll. A sway bar is obviously not designed to limit squat/dive or to hold the car up. In other words, you can go too stiff with coil or sways.

M3 vis ZSP? As I understand it the cross section is much different for the M3 sway. There is a lot more to consider than just diameter of the sway, but it doesn't sound like the front M3 and ZSP sways have the same characteristics.

I can understand that you don’t feel you need adjustable sways unless you are at the track. However, I want it for the street.

Honestly, we are talking about modifying a BMW suspension. Saying that one should modify the suspension (springs/sways, etc), and then not be able to modify the suspension (adjust dampening, front/rear balance & stiffness) strikes me as a oxymoron. Clearly though there are people who want a plug and play suspension, and people who want to tune their suspension themselves. That is a personal preference, not a right/wrong thing. You are correct that you can really screw things up handling wise if you don't know what you are doing.

Enjoy!
Chas

Originally Posted by roamer

Back to the original question though, the most significant tool for controlling roll is going to be springs. Sway bars are meant to supplement springs by allowing more compliant spring rates for better handling (stiffer is better only to a point), not to be the primary control of body roll. I would avoid a significantly stiffer rear without having an LSD. If you have the sports suspension, the difference between the M3 front and sport front sway is not significant, so you can get away with the M3 rear only with a LSD. As for adjustables, they are great if: (1) you track the car at a variety of tracks; and (2) you have the ability to objectively measure the setup to evaluate if the degree of stiffness and relationship between the front and rear stiffness is appropriate; for the street, they are overkill.

[Park828]

yup got HR full set and it stiffened up the car lateraly way too much. i switching to m3 bars now... this is not a mistake you wanna make.. rear install is a pita!

[vettegator005]

what would be a more dramatic handling improvement m3 sways or a set of good shocks?

[Robmaster]

i look on the BMW ETK and the M3 front sway bar has the same thickness than the 335i front sway bar. both are 26.5mm thick. so where's the difference?

[jbass524]

Originally Posted by vettegator005

what would be a more dramatic handling improvement m3 sways or a set of good shocks?

Good difference would be the shocks and springs or coilovers

Bad difference would be overly stiff swaybars.

[marconi118]

Originally Posted by Robmaster

i look on the BMW ETK and the M3 front sway bar has the same thickness than the 335i front sway bar. both are 26.5mm thick. so where's the difference?

all 1 and 3 series except M3 have a small portion in the middle that is thinner than 26.5mm. By changing this portion BMW changes the rate of the bar for different cars. The bar has a number like springs. For example 335i coupe is A4, bmw performance 135i has C7 (should be stiffer)

M3 bar has no reduced portion, it has full 26.5mm.
The E93 M3 bar is thicker 28mm, maybe overkill on a E92-335i but maybe ok for my E93-335i ????????