Sport Suspension, Includes Sway Bar Upgrade?

Blue Angel · 03-29-2011, 12:35 PM

Done some searching and can't find an answer... everyone's talking springs.

Does the OEM Sport Suspension for the e90 add stiffer front and rear sway bars over the stock suspension? If so, what are the diameters of the stock vs. SS sways?

Also, I couldn't find non-sport spring rates. The "spring rates" sticky at the top of the forum says "135i"... should this read "335i"? If so, are the standard (non-sport) 335i springs different than the 328i springs?

bigdaddycane · 03-29-2011, 12:39 PM

Nope. Same bars for both packages.

E90 Sways are 26.5mm in the front and 14mm in the rear.

Not sure about spring rates, but I don't think they're stiffer on the sport package.

John_01 · 03-29-2011, 07:20 PM

Rear bar is the same, but there are two bars with different part numbers for the front.
Standard front bar is 31356766287
ZSP front bar is 31356766288

Apparently the stock front bar is softer because it has a region in the center with reduced diamter.

Blue Angel · 03-29-2011, 10:28 PM

Interesting... so the sport package has a stiffer front bar and the same rear bar as the stock suspension... that's the opposite of what I would have thought. Sounds like they must have balanced the car by stiffening the front roll resistance with both the springs and the sway bar, and only adjusted the rear with the springs. I wonder if someone putting a set of sport springs and shocks without the upgraded front sway bar is setting themselves up for a bit of an oversteer situation?

John_01 · 03-29-2011, 10:54 PM

Quote:

Originally Posted by Blue Angel

I wonder if someone putting a set of sport springs and shocks without the upgraded front sway bar is setting themselves up for a bit of an oversteer situation?

I wouldn't think so. Plenty of people go for lower springs without chaning the front bar, and companies such as Eibach sell spring kits intended for the stock stay bars. If you use staggered tyres, its hard to imagine having a problem with oversteer. Maybe you can use DSC just to be sure

bigdaddycane · 03-29-2011, 10:59 PM

I have the ZHP suspension and I had the bar with the reduced diameter in the center. I replaced both with the M3 bars.

03-29-2011, 12:35 PM	#1
Blue Angel Major 1248 Rep 1,183 Posts Drives: 2011 323i and 2016 535d Join Date: Mar 2011 Location: Ottawa, ON iTrader: (0)	Sport Suspension, Includes Sway Bar Upgrade? Done some searching and can't find an answer... everyone's talking springs. Does the OEM Sport Suspension for the e90 add stiffer front and rear sway bars over the stock suspension? If so, what are the diameters of the stock vs. SS sways? Also, I couldn't find non-sport spring rates. The "spring rates" sticky at the top of the forum says "135i"... should this read "335i"? If so, are the standard (non-sport) 335i springs different than the 328i springs?
	Appreciate 0 Tweet Quote

03-29-2011, 12:39 PM	#2
bigdaddycane I even mod my cereal 268 Rep 3,480 Posts Drives: 11 ZCP DCT M3 14 328d 21 GT4 Join Date: Aug 2009 Location: Northern Va iTrader: (53) Garage List 2021 Porsche GT4 [0.00] 2014 BMW 328d Xdriv ... [0.00] 2011 BMW M3 [0.00]	Nope. Same bars for both packages. E90 Sways are 26.5mm in the front and 14mm in the rear. Not sure about spring rates, but I don't think they're stiffer on the sport package. __________________ 2011 Mineral White M3 ZCP - Opticoat, Ventureshield, some CF, B&B exhaust, AFE Intake Vorsteiner VFF 101s Ohlins 2014 Mineral White 328d Xdrive Wagon - Opticoat, Ventureshield, B8s, H&R, Apex SM-10s Hawk Pads 2021 718 Cayman GT4 - Fire extinguiser, Neodyme GT3 Wheel Color
	Appreciate 0 Quote

03-29-2011, 07:20 PM	#3
John_01 Colonel 237 Rep 2,643 Posts Drives: E90 325i, E82 135i Join Date: Mar 2009 Location: Sydney, Australia iTrader: (0)	Rear bar is the same, but there are two bars with different part numbers for the front. Standard front bar is 31356766287 ZSP front bar is 31356766288 Apparently the stock front bar is softer because it has a region in the center with reduced diamter.
	Appreciate 0 Quote

03-29-2011, 10:28 PM	#4
Blue Angel Major 1248 Rep 1,183 Posts Drives: 2011 323i and 2016 535d Join Date: Mar 2011 Location: Ottawa, ON iTrader: (0)	Interesting... so the sport package has a stiffer front bar and the same rear bar as the stock suspension... that's the opposite of what I would have thought. Sounds like they must have balanced the car by stiffening the front roll resistance with both the springs and the sway bar, and only adjusted the rear with the springs. I wonder if someone putting a set of sport springs and shocks without the upgraded front sway bar is setting themselves up for a bit of an oversteer situation?
	Appreciate 0 Quote

03-29-2011, 10:59 PM	#6
bigdaddycane I even mod my cereal 268 Rep 3,480 Posts Drives: 11 ZCP DCT M3 14 328d 21 GT4 Join Date: Aug 2009 Location: Northern Va iTrader: (53) Garage List 2021 Porsche GT4 [0.00] 2014 BMW 328d Xdriv ... [0.00] 2011 BMW M3 [0.00]	I have the ZHP suspension and I had the bar with the reduced diameter in the center. I replaced both with the M3 bars. __________________ 2011 Mineral White M3 ZCP - Opticoat, Ventureshield, some CF, B&B exhaust, AFE Intake Vorsteiner VFF 101s Ohlins 2014 Mineral White 328d Xdrive Wagon - Opticoat, Ventureshield, B8s, H&R, Apex SM-10s Hawk Pads 2021 718 Cayman GT4 - Fire extinguiser, Neodyme GT3 Wheel Color
	Appreciate 0 Quote