E90Post
 


 
BMW 3-Series (E90 E92) Forum > E90 / E92 / E93 3-series Technical Forums > All-Wheel-Drive (Xi / xDrive) Talk > Xi suspension- my $.02



Reply
 
Thread Tools Search this Thread
      08-30-2012, 09:00 PM   #1
BAL278
Captain
 
BAL278's Avatar
 
Drives: E92 335xi JB
Join Date: Jun 2011
Location: North NJ

Posts: 961
iTrader: (3)

Xi suspension- my $.02

Just sharing some experience tuning the suspension on an xi..
As you know, our cars tend to understeer.. The rwd's as well, but I think its worse on the awd platform..

In order to rectify this problem I first went and replaced the springs with Eibach ones.. I noticed the car was a bit more planted.. And there was significantly less body roll..

Step two was to replace the rear sway bar (what a flimsy POS) with an m3 one.. As was the recommendation from Sal at Autocouture to also replace the rear subframe bushings with m3 ones.. I did this probably six months ago.. So this is a bit overdue

What I've found is that the car feels SO much more balanced.. Understeer has been Dramatically reduced.. And dare I say it, i can even get the car to oversteer.. Turn in feels very sharp.. And the car feels the way it should have from the factory.. I will update this as soon as I install the Bilstein sports

I'm sure alot of you are running coilovers or lowering springs, but I HIGHLY recommend this mod.. It makes a big difference
__________________

2008 335xi Jet Black//Coral Red
Procede V5//VRSF DPs//AMS FMIC//KW V1//M3 Sways & Sub Bushings// Alpina AT flash
Apex EC-7//Hankook V12//Dinan CAI
BAL278 is offline  
0
Reply With Quote
      08-31-2012, 04:44 PM   #2
BrokenMyWallet12
Private
 
BrokenMyWallet12's Avatar
 
Drives: 2009 335xi
Join Date: Jul 2012
Location: New Jersey

Posts: 72
iTrader: (1)

Having the rear end on the XI feel a tad bit soft is excatly what i thought about when i drive it. Is that rear sway bar adjustable? Did you any of the tires get kicked out further than the stock bar?
BrokenMyWallet12 is offline   United_States
0
Reply With Quote
      08-31-2012, 04:57 PM   #3
802Bimmer
Enlisted Member
 
802Bimmer's Avatar
 
Drives: 08' 328xi 6mt
Join Date: Oct 2011
Location: VT

Posts: 34
iTrader: (1)

Garage List
2008 BMW 328xi  [0.00]
Thanks for the info! How are the Eibachs on the stock struts?? also how does the stance look, any reverse rake??

Quote:
Originally Posted by BAL278 View Post
Just sharing some experience tuning the suspension on an xi..
As you know, our cars tend to understeer.. The rwd's as well, but I think its worse on the awd platform..

In order to rectify this problem I first went and replaced the springs with Eibach ones.. I noticed the car was a bit more planted.. And there was significantly less body roll..

Step two was to replace the rear sway bar (what a flimsy POS) with an m3 one.. As was the recommendation from Sal at Autocouture to also replace the rear subframe bushings with m3 ones.. I did this probably six months ago.. So this is a bit overdue

What I've found is that the car feels SO much more balanced.. Understeer has been Dramatically reduced.. And dare I say it, i can even get the car to oversteer.. Turn in feels very sharp.. And the car feels the way it should have from the factory.. I will update this as soon as I install the Bilstein sports

I'm sure alot of you are running coilovers or lowering springs, but I HIGHLY recommend this mod.. It makes a big difference
802Bimmer is offline  
0
Reply With Quote
      08-31-2012, 05:46 PM   #4
pits200
Lieutenant Colonel
 
Drives: 09 335i X-Drive Black Sapphire
Join Date: Mar 2010
Location: Pittsburgh

Posts: 1,896
iTrader: (0)

I lowly recommend springs only. Ride will suffer and rebound will be subpar if you're going over bumps or imperfections.

I agree with the rest
pits200 is offline   United_States
0
Reply With Quote
      09-01-2012, 03:46 PM   #5
BAL278
Captain
 
BAL278's Avatar
 
Drives: E92 335xi JB
Join Date: Jun 2011
Location: North NJ

Posts: 961
iTrader: (3)

Quote:
Originally Posted by pits200
I lowly recommend springs only. Ride will suffer and rebound will be subpar if you're going over bumps or imperfections.

I agree with the rest
I agree with this.. Which is why I'm getting Bilsteins lol
__________________

2008 335xi Jet Black//Coral Red
Procede V5//VRSF DPs//AMS FMIC//KW V1//M3 Sways & Sub Bushings// Alpina AT flash
Apex EC-7//Hankook V12//Dinan CAI
BAL278 is offline  
0
Reply With Quote
      09-01-2012, 03:49 PM   #6
BAL278
Captain
 
BAL278's Avatar
 
Drives: E92 335xi JB
Join Date: Jun 2011
Location: North NJ

Posts: 961
iTrader: (3)

Quote:
Originally Posted by 802Bimmer
Thanks for the info! How are the Eibachs on the stock struts?? also how does the stance look, any reverse rake??

Quote:
Originally Posted by BAL278 View Post
Just sharing some experience tuning the suspension on an xi..
As you know, our cars tend to understeer.. The rwd's as well, but I think its worse on the awd platform..

In order to rectify this problem I first went and replaced the springs with Eibach ones.. I noticed the car was a bit more planted.. And there was significantly less body roll..

Step two was to replace the rear sway bar (what a flimsy POS) with an m3 one.. As was the recommendation from Sal at Autocouture to also replace the rear subframe bushings with m3 ones.. I did this probably six months ago.. So this is a bit overdue

What I've found is that the car feels SO much more balanced.. Understeer has been Dramatically reduced.. And dare I say it, i can even get the car to oversteer.. Turn in feels very sharp.. And the car feels the way it should have from the factory.. I will update this as soon as I install the Bilstein sports

I'm sure alot of you are running coilovers or lowering springs, but I HIGHLY recommend this mod.. It makes a big difference
The eibachs on stock struts.. It is livable lol.. I would recommend to upgrade them, but the drop isnt as aggressive as HR (imo the perfect amount of drop) so the ride isnt as harsh as those

Stance is great.. Could benefit from upgraded shocks.. I will update this when the Bilsteins are on
__________________

2008 335xi Jet Black//Coral Red
Procede V5//VRSF DPs//AMS FMIC//KW V1//M3 Sways & Sub Bushings// Alpina AT flash
Apex EC-7//Hankook V12//Dinan CAI
BAL278 is offline  
0
Reply With Quote
      09-01-2012, 04:14 PM   #7
Carl Morris
Captain
 
Drives: 2008 335xi 6MT
Join Date: Feb 2012
Location: Boulder, CO

Posts: 637
iTrader: (0)

Interesting. I'm not much of a suspension guy...I was thinking that the easiest way to reduce understeer on our cars would be to use camber/caster plates to get the front camber to match the rear. Due to liability issues I tend to assume that the factory has pretty much maximized the traction at the rear and not at the front to make sure there's plenty of understeer and that the fix is just a matter of increasing traction at the front.
Carl Morris is offline  
0
Reply With Quote
      09-01-2012, 05:16 PM   #8
BAL278
Captain
 
BAL278's Avatar
 
Drives: E92 335xi JB
Join Date: Jun 2011
Location: North NJ

Posts: 961
iTrader: (3)

Quote:
Originally Posted by Carl Morris
Interesting. I'm not much of a suspension guy...I was thinking that the easiest way to reduce understeer on our cars would be to use camber/caster plates to get the front camber to match the rear. Due to liability issues I tend to assume that the factory has pretty much maximized the traction at the rear and not at the front to make sure there's plenty of understeer and that the fix is just a matter of increasing traction at the front.
I agree completely, Understeer is the "safe" route.. The rear sway bar is incredibly flimsy.. I'm sure camber would increase front grip, but from my experience with only these mods.. It does a fantastic job of balancing the car.. The rear end just feels too soft.. Using these M3 components makes a noticeable difference
__________________

2008 335xi Jet Black//Coral Red
Procede V5//VRSF DPs//AMS FMIC//KW V1//M3 Sways & Sub Bushings// Alpina AT flash
Apex EC-7//Hankook V12//Dinan CAI
BAL278 is offline  
0
Reply With Quote
      09-06-2012, 03:51 PM   #9
MakkkD
Second Lieutenant
 
Drives: 09 e92 335xi
Join Date: Sep 2011
Location: Westchester, NY

Posts: 231
iTrader: (3)

what is the part number for the Eibach springs you installed?
MakkkD is offline   United_States
0
Reply With Quote
      09-07-2012, 07:09 PM   #10
don_zielke
New Member
 
Drives: 2007 328XI Sedan
Join Date: Aug 2012
Location: Columbus OH

Posts: 6
iTrader: (0)

Would this apply to coupe, sedan, or both?

Thanks,
Don Zielke
'07 328xi
don_zielke is offline  
0
Reply With Quote
      09-08-2012, 08:43 AM   #11
rwgeld58
New Member
 
Drives: 335i xdrive coupe
Join Date: Nov 2011
Location: Boone, NC

Posts: 12
iTrader: (0)

I put kw V1s on last Dec. which markedly improved the floaty feeling, but still feel some sway in curves compared to my prior e92 non-x. Based on yours and others comments, am thinking of doing the rear M3 sway. However, a guy who runs a specialty bmw shop near me actually recommended against it, but I think he may not be as familiar with x-drive issues with suspension. How much should install run?
rwgeld58 is offline  
0
Reply With Quote
      09-10-2012, 10:38 AM   #12
AWD Addict
Chief Executive
 
AWD Addict's Avatar
 
Drives: 2008 335xi 6spd Coupe
Join Date: Dec 2007
Location: Boston

Posts: 2,483
iTrader: (1)

Garage List
2008 335xi  [0.00]
Good tire pressure management can also go a long way to dialing out the understeer. On the stock setup before I upgraded, I found the bias to be pretty close to neutral (though it did still push a bit) with 32/36 F/R psi.

Combined with my new stuts, the car feels dramatically improved. I was thinking about a rear sway and bushings next, but given how much better the car feels, I'm probably going to hold off for a while.
AWD Addict is offline  
0
Reply With Quote
      09-20-2012, 08:48 AM   #13
BAL278
Captain
 
BAL278's Avatar
 
Drives: E92 335xi JB
Join Date: Jun 2011
Location: North NJ

Posts: 961
iTrader: (3)

Quote:
Originally Posted by rwgeld58 View Post
I put kw V1s on last Dec. which markedly improved the floaty feeling, but still feel some sway in curves compared to my prior e92 non-x. Based on yours and others comments, am thinking of doing the rear M3 sway. However, a guy who runs a specialty bmw shop near me actually recommended against it, but I think he may not be as familiar with x-drive issues with suspension. How much should install run?
Install was about 4 hours for the Rear Sway and subframe bushings
__________________

2008 335xi Jet Black//Coral Red
Procede V5//VRSF DPs//AMS FMIC//KW V1//M3 Sways & Sub Bushings// Alpina AT flash
Apex EC-7//Hankook V12//Dinan CAI
BAL278 is offline  
0
Reply With Quote
      02-02-2013, 01:04 PM   #14
drsilvershot
Second Lieutenant
 
drsilvershot's Avatar
 
Drives: 08 335xi jet black
Join Date: Dec 2011
Location: providence, ri

Posts: 281
iTrader: (5)

still available?
drsilvershot is offline   United_States
0
Reply With Quote
      02-03-2013, 07:48 PM   #15
suave5274
Enlisted Member
 
Drives: 335xi
Join Date: Dec 2010
Location: CT

Posts: 48
iTrader: (0)

Does the 22.5 m3 rear sway bar fit a 2007 e90 335xi
suave5274 is offline  
0
Reply With Quote
      02-04-2013, 09:31 AM   #16
jeguth1s
Private First Class
 
jeguth1s's Avatar
 
Drives: 2006 BMW 330xi
Join Date: Nov 2010
Location: Cincinnati

Posts: 186
iTrader: (1)

Yes. All the E9x rears have the same config Sway. Just different thickness.
jeguth1s is offline   United_States
0
Reply With Quote
      02-04-2013, 10:08 AM   #17
Richbot
Colonel
 
Drives: Jerez Black E90
Join Date: Sep 2007
Location: STL

Posts: 2,033
iTrader: (2)

Single best thing you can do to improve balance on a street BMW is add more front camber. The best way to do this, counterintuitively, is often to add a stiffer front swaybar to keep the front suspension in its happy place, because the front suspension geometry de-cambers the tire as it travels through its range of motion in bump. The E90 chassis is much better than past designs in this regard but still not as good as some double wishbone setups which can get by with less than a degree of negative camber and still keep the tire square to the road in a corner. A bigger rear bar just takes grip away from the rear especially under acceleration, what the car needs is more front grip
__________________
Richbot is offline  
0
Reply With Quote
      02-05-2013, 12:53 PM   #18
MSport35TT
Captain
 
Drives: 335i
Join Date: Oct 2012
Location: NJ & MA

Posts: 678
iTrader: (4)

Garage List
2010 BMW 335ix  [0.75]
Quote:
Originally Posted by Richbot View Post
Single best thing you can do to improve balance on a street BMW is add more front camber. The best way to do this, counterintuitively, is often to add a stiffer front swaybar to keep the front suspension in its happy place, because the front suspension geometry de-cambers the tire as it travels through its range of motion in bump. The E90 chassis is much better than past designs in this regard but still not as good as some double wishbone setups which can get by with less than a degree of negative camber and still keep the tire square to the road in a corner. A bigger rear bar just takes grip away from the rear especially under acceleration, what the car needs is more front grip
I though most would disagree to replace the front sway vs the Rear...
__________________
TiAg N54 xDrive M-Sport 6MT 2010 I:I N54 I:I CPO-2016
335i SOLD

TMPS Sensor 09+ For Sale
x1 Seat Belt For Sale
MSport35TT is offline   United_States
0
Reply With Quote
      02-05-2013, 07:12 PM   #19
suave5274
Enlisted Member
 
Drives: 335xi
Join Date: Dec 2010
Location: CT

Posts: 48
iTrader: (0)

Quote:
Originally Posted by MSport35TT View Post
I though most would disagree to replace the front sway vs the Rear...
Correct thats what iv heard too. Rear> Front , although what he said about front>rear does make sense as he explained .
suave5274 is offline  
0
Reply With Quote
      02-11-2013, 01:36 PM   #20
SDV325
N54 or N55?
 
SDV325's Avatar
 
Drives: 99 Impreza 2.5RS
Join Date: Jan 2013
Location: Calgary, AB

Posts: 49
iTrader: (0)

Changing out the swaybars and endlinks are usually the first step in tuning AWD suspension (well technically tires first). You will greatly benefit more from having stiffer swaybars/bushings prior to doing springs/shocks.

Coming from the Subaru scene this is quite common and companies like whiteline have a very good reputation and parts selection. Was quite surprised on how many BMW parts were made as well.

http://www.whiteline.com.au/do_segue...3%2F05-10%2F11
__________________
SDV325 is offline   Canada
0
Reply With Quote
      02-11-2013, 02:02 PM   #21
pits200
Lieutenant Colonel
 
Drives: 09 335i X-Drive Black Sapphire
Join Date: Mar 2010
Location: Pittsburgh

Posts: 1,896
iTrader: (0)

Quote:
Originally Posted by SDV325 View Post
Changing out the swaybars and endlinks are usually the first step in tuning AWD suspension (well technically tires first). You will greatly benefit more from having stiffer swaybars/bushings prior to doing springs/shocks.

Coming from the Subaru scene this is quite common and companies like whiteline have a very good reputation and parts selection. Was quite surprised on how many BMW parts were made as well.

http://www.whiteline.com.au/do_segue...3%2F05-10%2F11

Unfortunately, such is not true with the bmw due to the complexity of swapping out the rear sway and needing to drop the subframe.
pits200 is offline   United_States
0
Reply With Quote
      02-13-2013, 06:02 PM   #22
Bryan71
New Member
 
Drives: 2006 325XI
Join Date: Feb 2011
Location: Harrisburg, PA

Posts: 6
iTrader: (0)

with B8 bilstein's, correct? what is the part number for the Eibach's you put on?
Bryan71 is offline  
0
Reply With Quote
Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -5. The time now is 10:56 PM.




e90post
Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST