Adding Sway Bars

jclaib7 · 06-18-2014, 08:05 PM

My understanding is that the stock 128i has no front or rear sway bar.

The M sport package adds an 11 mm front sway bar and no rear sway bar. (Not 100% sure about this)

I have an appointment next week to upgrade my M Sport front sway bar to the M3 28mm front sway bar.

I may also add the H&R rear 20mm sway bar.

Let's be honest though, i'm not completely sure what the overall impact on the car will be. It has the M sport stiffer suspension. I have no plans to add coilovers/shocks/suspension. The ride is fairly rough as it is.

What will the overall impact on the car be if I go with both front and rear bars?

I'm looking to just tighten the car up a bit overall without sacrificing too much ride quality.

TJ710 · 06-18-2014, 08:19 PM

I would start with just a front sway bar. This is what I did with my e46 and I loved it. When I added the rear sway bar I noticed less of a difference and ride became way more rough.

Kgolf31 · 06-18-2014, 08:39 PM

The stock car has a front sway bar. The M Sport package adds 1mm to the front diameter. I think that puts it at a 26.5mm on the outside at 24mm in the middle?

The stock car has no rear bar. The M Sport package has an 11mm rear bar, IIRC

Adding bars will help increase turn-in. I found that the front bar increases understeer regardless of camber...and you really need a rear bar to maintain overall balance. IMO.

Ride quality will not be effected UNLESS you hit an uneven bump...then you will see an increase in harshness because you have a bigger bar which is effecting your roll rigidity.

Makes sense?

06-18-2014, 08:05 PM	#1
jclaib7 First Lieutenant 142 Rep 324 Posts Drives: 2018 M2 Black Shadow Edition Join Date: Jul 2013 Location: United States, Beverly Ma. iTrader: (2)	Adding Sway Bars My understanding is that the stock 128i has no front or rear sway bar. The M sport package adds an 11 mm front sway bar and no rear sway bar. (Not 100% sure about this) I have an appointment next week to upgrade my M Sport front sway bar to the M3 28mm front sway bar. I may also add the H&R rear 20mm sway bar. Let's be honest though, i'm not completely sure what the overall impact on the car will be. It has the M sport stiffer suspension. I have no plans to add coilovers/shocks/suspension. The ride is fairly rough as it is. What will the overall impact on the car be if I go with both front and rear bars? I'm looking to just tighten the car up a bit overall without sacrificing too much ride quality. __________________ 2018 M2 Black Shadow Edition
	Appreciate 0 Tweet Quote

06-18-2014, 08:19 PM	#2
TJ710 Private First Class 35 Rep 120 Posts Drives: 2011 135i Join Date: Apr 2014 Location: Edina, Mn iTrader: (0)	I would start with just a front sway bar. This is what I did with my e46 and I loved it. When I added the rear sway bar I noticed less of a difference and ride became way more rough.
	Appreciate 0 Quote

06-18-2014, 08:39 PM	#3
Kgolf31 Brigadier General 459 Rep 4,531 Posts Drives: 2007 Z4MC, 2012 128i Join Date: Sep 2008 Location: Ohio iTrader: (4)	The stock car has a front sway bar. The M Sport package adds 1mm to the front diameter. I think that puts it at a 26.5mm on the outside at 24mm in the middle? The stock car has no rear bar. The M Sport package has an 11mm rear bar, IIRC Adding bars will help increase turn-in. I found that the front bar increases understeer regardless of camber...and you really need a rear bar to maintain overall balance. IMO. Ride quality will not be effected UNLESS you hit an uneven bump...then you will see an increase in harshness because you have a bigger bar which is effecting your roll rigidity. Makes sense?
	Appreciate 0 Quote