Sway Bars

SROC3 · 04-04-2007, 03:22 AM

This may have been beaten to death already but i need to ask quick as I am getting them tomorrow. If I get the H&R sway bars for my 335i, should i get both? or is only the rear necessary? I realize the handling characteristics of a sedan may be different so input anyone? (I have the coupe btw).

Also, this upgrade will improve the "solid" feel of the car right? or is that the job of the strut tower brace?

Thanks!!!

teknochild · 04-04-2007, 03:40 AM

Quote:

Originally Posted by SROC3

This may have been beaten to death already but i need to ask quick as I am getting them tomorrow. If I get the H&R sway bars for my 335i, should i get both? or is only the rear necessary? I realize the handling characteristics of a sedan may be different so input anyone? (I have the coupe btw).

Also, this upgrade will improve the "solid" feel of the car right? or is that the job of the strut tower brace?

Thanks!!!

basically what it does is make it so when your left rear wheel goes up, so does your right rear wheel, in corners it will make the car flatter instead of tilting to the side at the expense of a less comfortable ride (if you go over a bump on one wheel you dont really want it transfered across the whole axle)

strut tower brace suposedly improves rigidity crating a sharper turn in (car responds faster when you turn)

just4kickz · 04-05-2007, 05:54 PM

Quote:

Originally Posted by teknochild

basically what it does is make it so when your left rear wheel goes up, so does your right rear wheel, in corners it will make the car flatter instead of tilting to the side at the expense of a less comfortable ride (if you go over a bump on one wheel you dont really want it transfered across the whole axle)

strut tower brace suposedly improves rigidity crating a sharper turn in (car responds faster when you turn)

+1... you can also visualize that when you turn hard... it feels like the outer wheels aren't gripping the road as well and maybe skidding... the sway bars reduce that quite a bit...

Fraggy · 04-05-2007, 06:30 PM

I would get both front and rear. I have the rear only and love it. I do plan on getting the front someday as well, but the rear is the most valuable. You can check their diameters in a few threads by searching, and also I believe there is a sticky in the suspension sub-forum.

ksfrogman · 04-06-2007, 02:23 AM

I thought I'd chime in on this one too. Most of what people have said above is true. The sway bars keep the car flatter to diminish tilting (sway), keeping the outer tires planted more flat against the road, improving the contact surface area. However, more of the car's weight is also shifted to the outer wheels/tires when making turns. Ride quality is also compromised somewhat, though I have no regrets about going with front and rear sway bars. I will admit that when braking and making a quick 180 degree U-turn, the car tends to plow a bit more than I would like it. I wonder if this would be diminished by not having such a thick front sway bar.

As much as this subject has been beaten to death, I gather that people have a hard time understanding how these bars work, because they haven't gone under their cars to see where the bars are, i.e., how they connect the car's body to the strucures that hold the wheels (indirectly). Think of a flimsy corrugated box as the car's body, and this box is on wheels that attach to the 4 corners with 4 soft springs. Whenever this "box" car turns, it leans to the opposite side. The sway bars are solid bars that attach the cardboard box to the wheels to diminish leaning. Strut bars can be thought of as pieces that increase the rigidity of the box structure itself so that the box doesn't deform or change shape (say into a parallelogram) when stressed.

I had the opportunity to ride in the Dinan E90, which keeps the stock sway bars, but changes the spring rates and shocks. It had a very nice ride and handled well around corners without much fanfare either. The ride was very compliant. So I think there are many variables one should consider before jumping blindly into a purchase.

stressdoc · 04-06-2007, 11:32 PM

Quote:

Originally Posted by ksfrogman

I think there are many variables one should consider before jumping blindly into a purchase.

Amen.

HRC · 04-07-2007, 01:34 AM

One lone voter here for rear bar only!

Mike, with the stock front, and the H&R rear, plow will be reduced.

Danny

OhhaiAlex · 04-07-2007, 03:12 AM

I say both. Balance it out.

ScBlacksunshine · 04-07-2007, 03:19 AM

Quote:

Originally Posted by HRC

One lone voter here for rear bar only!

Mikel, with the stock front, and the H&R rear, plow will be reduced.

Danny

Haha you're not alone...love my rear sway only setup

ksfrogman · 04-07-2007, 03:40 AM

Quote:

Originally Posted by HRC

One lone voter here for rear bar only!

Mike, with the stock front, and the H&R rear, plow will be reduced.

Danny

I know that.

Putting a heavy baby in the back seat will also increase oversteer.

montreal_bimmer · 04-10-2007, 09:19 AM

i plan on going with just the rear aswell....

canucklion · 04-10-2007, 09:57 AM

I vote for both, but I support Danny's decision

Quote:

Originally Posted by HRC

One lone voter here for rear bar only!

Mike, with the stock front, and the H&R rear, plow will be reduced.

Danny

SROC3 · 04-11-2007, 03:28 AM

Looks like I'll go rear first and see what the handling is like......then go for the fronts if I need more turn in.

Thanks everyone!!! As usual, a rockin set of answers to my question.

cupspeed · 04-12-2007, 03:51 AM

Both is better. One is fine

obLu · 04-12-2007, 04:24 PM

Ultimately, you want to make sure that any bar you buy is adjustable. Without being able to tune the stiffness you're not really setting the car up to your driving style.

Some people like ultra quick turn in, for them a stiff front bar makes sense. Some like oversteer, stiff bar out back. If both are adjustable you can set the stiffness up to be as close to neutral as possible.

I've learned to stay away from aftermarket sways for two reasons.
1. If they're adjustable (and this is the same reason I tried to shy away from coilovers this time too) I'll constantly find some reason that adjusting them "this" way will be beneficial. Much to my wife's chagrin. Many a saturday has been blown when I wake up early and decide, "I can adjust it real quick and have it buttoned back up before she even wakes up".

2. I haven't had an aftermarket bar yet that didn't make contact with some part of the frame or axle at the extreme ends of suspension travel once the car was lowered. Usually the adjustable end is too long, and then when you set it full still (hole furthest from the end) you loose that 1/16" clearance that you needed.

I'd also be willing to bet that a lot of people who are plowing an e90 came from front drivers. In steady state cornering you should get just a little plow, but if you're plowing in transition, or tight corners, you're getting on the throttle too early. A habit I had to break coming back to RWD after driving AWD for a few years.

04-04-2007, 03:22 AM	#1
SROC3 The limit of adhesion is my home. 1731 Rep 3,778 Posts Drives: Like a Boss. Join Date: Sep 2006 Location: three.one.zero iTrader: (1)	Sway Bars This may have been beaten to death already but i need to ask quick as I am getting them tomorrow. If I get the H&R sway bars for my 335i, should i get both? or is only the rear necessary? I realize the handling characteristics of a sedan may be different so input anyone? (I have the coupe btw). Also, this upgrade will improve the "solid" feel of the car right? or is that the job of the strut tower brace? Thanks!!! __________________ 2019 X3 xDrive30i Glacier Silver \| Cognac w/ Fine Cove \| MSport \| Premium \| Dynamic Handling PKG \| Drive Assist \| HK w/ Bavsound Upgrade \|
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04-05-2007, 06:30 PM	#4
Fraggy Brigadier General 198 Rep 3,469 Posts Drives: 2016 M3 Join Date: Jun 2005 Location: San Diego iTrader: (11)	I would get both front and rear. I have the rear only and love it. I do plan on getting the front someday as well, but the rear is the most valuable. You can check their diameters in a few threads by searching, and also I believe there is a sticky in the suspension sub-forum. __________________ 2016 Alpine White M3 (gone) 2019 Alfa Romeo Guilia (Totaled) 2020 Car-less 😁 (no more) 2020 M340
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04-06-2007, 02:23 AM	#5
ksfrogman Major General 613 Rep 6,750 Posts Drives: E90 330i 6MT Join Date: Nov 2005 Location: Torrance, CA iTrader: (12) Garage List 2006 330i [0.00] 2006 330i [0.00]	I thought I'd chime in on this one too. Most of what people have said above is true. The sway bars keep the car flatter to diminish tilting (sway), keeping the outer tires planted more flat against the road, improving the contact surface area. However, more of the car's weight is also shifted to the outer wheels/tires when making turns. Ride quality is also compromised somewhat, though I have no regrets about going with front and rear sway bars. I will admit that when braking and making a quick 180 degree U-turn, the car tends to plow a bit more than I would like it. I wonder if this would be diminished by not having such a thick front sway bar. As much as this subject has been beaten to death, I gather that people have a hard time understanding how these bars work, because they haven't gone under their cars to see where the bars are, i.e., how they connect the car's body to the strucures that hold the wheels (indirectly). Think of a flimsy corrugated box as the car's body, and this box is on wheels that attach to the 4 corners with 4 soft springs. Whenever this "box" car turns, it leans to the opposite side. The sway bars are solid bars that attach the cardboard box to the wheels to diminish leaning. Strut bars can be thought of as pieces that increase the rigidity of the box structure itself so that the box doesn't deform or change shape (say into a parallelogram) when stressed. I had the opportunity to ride in the Dinan E90, which keeps the stock sway bars, but changes the spring rates and shocks. It had a very nice ride and handled well around corners without much fanfare either. The ride was very compliant. So I think there are many variables one should consider before jumping blindly into a purchase. __________________
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04-07-2007, 01:34 AM	#7
HRC MAUI BUILT 499 Rep 7,781 Posts Drives: 2006 330i MT Join Date: Jun 2005 Location: NORCAL iTrader: (10) Garage List 2002 E46 325i [0.00] 2012 E70 35i [0.00]	One lone voter here for rear bar only! Mike, with the stock front, and the H&R rear, plow will be reduced. Danny __________________ Arctic/Blk Leather/Alum.Trim/MT/ZSP/Sunshades/Blk Lines/M3 Illuminated Knob/Alcantara Performance Wheel/M-E-Brake Handle/Euro Fog Switch/Koni Yellows/H&R Sport Springs/19" VMR V718's w/PS2 Tires/M-Tech Body Kit/Carbon Fiber Spoiler/Bimmian Interior Bulbs/OEM Eye Glass Tray/SSK/Alcantara Boot/Split Armrest/OEM Dual Rear Power Outlets/Rear Ashtray Delete/OEM Alum. Pedals/Osram 6000K/Brex Rings/LED Side Markers/BMS Power Box Last edited by HRC; 04-07-2007 at 03:26 AM..
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04-07-2007, 03:12 AM	#8
OhhaiAlex Oh hai :) 50 Rep 3,880 Posts Drives: M3 Join Date: Mar 2007 Location: Santa Clara iTrader: (0)	I say both. Balance it out. __________________
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04-10-2007, 09:19 AM	#11
montreal_bimmer OEMconcept 180 Rep 5,593 Posts Drives: BMW Join Date: Feb 2006 Location: Canada \| USA iTrader: (6) Garage List 2006 325i [10.00]	i plan on going with just the rear aswell....
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04-11-2007, 03:28 AM	#13
SROC3 The limit of adhesion is my home. 1731 Rep 3,778 Posts Drives: Like a Boss. Join Date: Sep 2006 Location: three.one.zero iTrader: (1)	Looks like I'll go rear first and see what the handling is like......then go for the fronts if I need more turn in. Thanks everyone!!! As usual, a rockin set of answers to my question. __________________ 2019 X3 xDrive30i Glacier Silver \| Cognac w/ Fine Cove \| MSport \| Premium \| Dynamic Handling PKG \| Drive Assist \| HK w/ Bavsound Upgrade \|
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04-12-2007, 03:51 AM	#14
cupspeed Second Lieutenant 12 Rep 277 Posts Drives: E90 M3 Join Date: Mar 2007 Location: Los Angeles iTrader: (0)	Both is better. One is fine
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04-12-2007, 04:24 PM	#15
obLu Major 55 Rep 1,159 Posts Drives: 330i 6MT ZSP Join Date: Jun 2005 Location: Kirkland, WA, USA iTrader: (1)	Ultimately, you want to make sure that any bar you buy is adjustable. Without being able to tune the stiffness you're not really setting the car up to your driving style. Some people like ultra quick turn in, for them a stiff front bar makes sense. Some like oversteer, stiff bar out back. If both are adjustable you can set the stiffness up to be as close to neutral as possible. I've learned to stay away from aftermarket sways for two reasons. 1. If they're adjustable (and this is the same reason I tried to shy away from coilovers this time too) I'll constantly find some reason that adjusting them "this" way will be beneficial. Much to my wife's chagrin. Many a saturday has been blown when I wake up early and decide, "I can adjust it real quick and have it buttoned back up before she even wakes up". 2. I haven't had an aftermarket bar yet that didn't make contact with some part of the frame or axle at the extreme ends of suspension travel once the car was lowered. Usually the adjustable end is too long, and then when you set it full still (hole furthest from the end) you loose that 1/16" clearance that you needed. I'd also be willing to bet that a lot of people who are plowing an e90 came from front drivers. In steady state cornering you should get just a little plow, but if you're plowing in transition, or tight corners, you're getting on the throttle too early. A habit I had to break coming back to RWD after driving AWD for a few years.
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