[bigdaddycane]

A little background on my car:
I had previously install KW V1 coilovers on my 07 335 and really liked the setup. But the more I drove the car I realized that something was off.; nothing major, but the car was twitchy and I attributed it to the very small rear sway bar. The 335 comes with a 26.5 mm front sway bar and a 13mm rear. The oem rear sway bar can be mistaken for a brake line; it’s tiny! I’ve seen Honda Accords with bigger rear sway bars!

Anyway, I did some research and the aftermarket sway bars (Hotchkis and H&R) are really expensive so I started looking at the oem M3 sways. The M3 has a 26.5mm front sway bar and a 20mm rear sway bar. Those sizes are very close to the aftermarket sway bar kits. The bushings are also much stiffer than the stock 335 sway bar bushings due to their makeup which is rubber coated steel bearings. The front and rear sway bars, bushings and clamps run ~$310 before shipping from Faulkner BMW in Pa. Most aftermarket kits are near $400 or more. Part numbers can be found on realoem.com. I can post them here if anyone is interested as well.

Also, the E90 M3 Convertible runs a 23.5 rear bar, but I did not want to go this extreme as I wanted to keep the car balanced. I noted this for anyone who is looking for something more extreme. The cost is the same as the non-convertible rear sway bar.

Now to the install:
The front bar is very straightforward and does not take much time (approx 45 mins). Why change the front when they are the same size you ask? Well, the stock 335 front sway bar has a taper in two spots and the M3 sway does not. The taper affects the bar’s affective rate. Also, the M3 bushings are rubber coated steel bearings, not just rubber bushings like the 335 bar uses.

The rear sway bar is a giant m*thaf*ker. Basically you have to lower the entire rear subframe and exhaust to make room to fish the bigger M3 sway bar into place. Probably took 2.5 hours to do but could be done faster now because of lessons learned. Basically, any suspension work in the rear of the 335 is a PITA.
Fitment for front and rear is perfect.

Driving impressions:
Wow! Much better, this is the way the car should have come from the factory. Huge improvement in the rear and the understeer is minimized. 7mm makes a noticeable difference. There is a bit more “road noise” but nothing that could be considered annoying.

Overall, I’m really happy with this upgrade even though the install was draining.

Here are some comparison pictures of the stock 335 rear sway bar and the stock M3 sway bar that replaced it.

[PaulBailey@ltbmw]

Nice!!
I needs sways so bad!

[lawgone]

Wow, the originals ARE tiny! That's surprising.

[2kaccordocoupe]

nice upgrade, may have to price out tischer

[Verbiage]

Fack. Its like a hot dog and a horse penis.

[brocklanders]

that is a big difference, but keep in mind that there are other differences in the m3 over the 335 or any other e90 92 or 93. if you notice dinan does not offer rear bars that size, i think its because they try to keep the car safe and comfortable while providing an improved performance feel to justify their clients spending money. this is why i chose the eibach sways over m3, it keeps the bias the same while providing a stiffer suspension. not to mention if you stiffen up the rear too much without an lsd you are going to dramatically lose traction defeating the purpose of suspension "upgrades".

[stressdoc]

Impressive that you DIY'd the rear!
Definitely need LSD with M3 rear sway. Also recommend M3 rear subframe bushings.
Probably need alignment.

[bigdaddycane]

nice upgrade, may have to price out tischer

Give Faulkner a try....they are cheaper than Tischer and they are in the same shipping zone.

that is a big difference, but keep in mind that there are other differences in the m3 over the 335 or any other e90 92 or 93. if you notice dinan does not offer rear bars that size, i think its because they try to keep the car safe and comfortable while providing an improved performance feel to justify their clients spending money. this is why i chose the eibach sways over m3, it keeps the bias the same while providing a stiffer suspension. not to mention if you stiffen up the rear too much without an lsd you are going to dramatically lose traction defeating the purpose of suspension "upgrades".

I realize this as I said, I did my homework and this is not my first suspension rodeo. I have modded several cars before this.

The M3 set up is moderate and there is no dramatic lose of traction.

The main issue to be concerned with in chosing sway bars is if the car will OVERSTEER more due to the larger bars (specifically the rear). This is, as I said, why I stayed away from the larger M3 convertible bar.

Definitely need LSD with M3 rear sway. Also recommend M3 rear subframe bushings.
Probably need alignment.

Thanks, I had a great mechanic with me....excellent tools as well. Makes a big difference having someone that has done the install before.

LSD is NOT needed, but I will definitely do the subframe bushings.

Alignment is NOT needed as the lower control arms were not disconnected and the coilover settings never changed.

[AlanAZ]

I recently upgraded to the 14 mm M-sport rear bar (leaving the front zsp), and it has done a lot to balance up the car.

[bigdaddycane]

Here is the links to the site I used to get the part numbers. Write down the part numbers then go to Faulkner BMWs site.

Note: You don't need the nuts. Use your existing hardware.

Front Sway Bar
http://www.realoem.com/bmw/showparts...04&hg=31&fg=10

Rear Sway Bar
http://www.realoem.com/bmw/showparts...11&hg=33&fg=45

[SHOWTIME]

Originally Posted by AlanAZ

I recently upgraded to the 14 mm M-sport rear bar (leaving the front zsp), and it has done a lot to balance up the car.

M - Sport has a slightly thicker rear sway bar than regular? did not know that

[bigdaddycane]

1mm thicker.....not that noticeable. If it comes with upgraded bushings that would be more noticeable.

[cvc 22349a]

Originally Posted by AlanAZ

I recently upgraded to the 14 mm M-sport rear bar (leaving the front zsp), and it has done a lot to balance up the car.

Alan,

I'm considering the 14mm rear sway, instead of the M3 f/r bars, with my zsp springs and koni fsd's. What is your spring shock combo? Do you still drive on rft's? What difference do you feel going up from the 13mm bar?

tia

[AlanAZ]

M - Sport has a slightly thicker rear sway bar than regular? did not know that

The older M-sport performance suspension had this rear bar, while the newer performance suspension has a heavier front bar, which seems counter-intuitive.

1mm thicker.....not that noticeable. If it comes with upgraded bushings that would be more noticeable.

It's not just diameter, but composition, it felt noticeably heavier than a 1mm difference, and the shape, it was straighter (and i think stiffer) after the bend going to the links. It does use different bushings.

I'm considering the 14mm rear sway, instead of the M3 f/r bars, with my zsp springs and koni fsd's. What is your spring shock combo? Do you still drive on rft's? What difference do you feel going up from the 13mm bar?

I have zsp springs with old performance pkg struts/shocks. Front lowering perches and Meyle HD control arms going on next week (and m3 front strut brace back on.) No RFTs, RE760s on 18s, 225f, 255b.

Quite a bit flatter at back, seems balanced with the front now (stock zsp front bar), some freeway ramp curves were down-right scary before (now it's more like my E46 was.) The ride is about perfect, stiffer, but not too much -- stiffer sways also stiffen up the ride. I didn't want to be in the situation where I over-did the back, then I'd have to do the front, and now have a car more suited for the track than everyday driving. The only other bar I considered was the Eibach 15mm, but figured the 14mm was designed to work with my struts/stocks/springs combo.

[bigdaddycane]

The shape will NOT be that different (if at all) seeing that it's coming from BMW. If you look at my pics you'll see the M3 bar is the exact same shape as the stock 335 bar.

You are most likely benefitting from the bushings.

The Eibach rear sway is a nice comprimise between stock and the M3 bar.

[AlanAZ]

The shape will NOT be that different (if at all) seeing that it's coming from BMW. If you look at my pics you'll see the M3 bar is the exact same shape as the stock 335 bar.

I don't have the M3 bar, I have the 14 mm, and the shape is different. Looking at the stock bar in the photos above and here (driver's side), the two minor bends between the first bend after where the bushing would be and the big arc to where the end links attach, are gone. The next time I have a rear wheel off, I'll photo the new bar and attach.

[ADV.1 Matt]

Swaybars have some of the biggest impact (and are some of the least expensive mods) on handling. I'm surprised it isn't the "go to" handling modification for more people.

Thanks for posting up the detailed review!

[ShyGuy]

what's the part # on the M3 sway?

[bigdaddycane]

don't have the M3 bar, I have the 14 mm, and the shape is different.

I know you don't have the M3 bar....I have been reading this post. You have a BMW Performance bar which is produced by BMW. That is what I was referencing.

I would be interested to see photos

I listed links to the part number above

Here is the links to the site I used to get the part numbers. Write down the part numbers then go to Faulkner BMWs site.

Note: You don't need the nuts. Use your existing hardware.

Front Sway Bar
http://www.realoem.com/bmw/showparts...04&hg=31&fg=10

Rear Sway Bar
http://www.realoem.com/bmw/showparts...11&hg=33&fg=45

[ShyGuy]

your links dont' work...

[DaFish]

Originally Posted by brocklanders

that is a big difference, but keep in mind that there are other differences in the m3 over the 335 or any other e90 92 or 93. if you notice dinan does not offer rear bars that size, i think its because they try to keep the car safe and comfortable while providing an improved performance feel to justify their clients spending money. this is why i chose the eibach sways over m3, it keeps the bias the same while providing a stiffer suspension. not to mention if you stiffen up the rear too much without an lsd you are going to dramatically lose traction defeating the purpose of suspension "upgrades".

I did the Dinan Stage 3 - not the rear bar... due to the fact they recommend a LSD at the same time due to loss of traction with just doing the rear bar and no LSD.

I am doing both now - I did do the Dinan rear bar to match the Stage 3.. I felt I had to stick with Dinan on the rear bar. If was to do this over, I would do the M3 bars and a setup from Harold with Swifts...but I didn't.

I'll post up how my rear bar affects things when I get it on with the LSD (doing the subframe bushings at the same time).

And ya, I spent way too much fn money... the Dinan rear bar along was $369 before shipping, taxes and duty . I might as well have given them a kidney...

[chrisw335i]

better off saving your money and just changing the bushings..cost ya like 25 bucks for the m3 sway bar bushings..cause there isnt much of a difference at all between the sports package sway and m3 sway.just the bushings