BMW 1 Series Coupe Forum / 1 Series Convertible Forum (1M / tii / 135i / 128i / Coupe / Cabrio / Hatchback) (BMW E82 E88 128i 130i 135i)
 





 

Post Reply
 
Thread Tools Search this Thread
      04-22-2019, 11:50 AM   #133
vincefreeflyer
New Member
France
26
Rep
25
Posts

Drives: 135I e82
Join Date: Apr 2019
Location: france

iTrader: (0)

hey, what's new with your spherical bushings on trailing arm and camber arm?

I plan to install ball link toe and M3 guid rod on my 135I.
What do you think about this toe arm : https://www.ebay.com/itm/06-12-E90-E...cAAOSw3bBceZOl

They seem to be ball linked, cheap but maybe anybody try this ...

there is also the cheap of the cheap version : https://fr.aliexpress.com/item/rear-...811057537.html
Appreciate 0
      07-10-2019, 08:17 PM   #134
chicken Legs
New Member
0
Rep
6
Posts

Drives: 2011 space silver 135i
Join Date: May 2018
Location: canada

iTrader: (0)

been going threw all this suspension setups looking for the best solution for my 2011 135i DCT rear end moves a lot side to side over bumps any thoughts ..I'm in canada roads arn't the best ( frost )
Appreciate 0
      07-10-2019, 09:22 PM   #135
AndyW
Supreme Galactic Commander (one galaxy over...)
AndyW's Avatar
United_States
518
Rep
1,834
Posts

Drives: 2008 335i E93 & 2012 135i E82
Join Date: Feb 2012
Location: Washington, USA

iTrader: (5)

Quote:
Originally Posted by chicken Legs View Post
been going threw all this suspension setups looking for the best solution for my 2011 135i DCT rear end moves a lot side to side over bumps any thoughts ..I'm in canada roads arn't the best ( frost )
Upgrade the Rear Subframe Bushings (RSFB). Whiteline makes a decent 2-piece poly set.
__________________
Best,
Andy

'12 E82-PS2,Stoptechs,Clubsports+M3 bits,Accusump,Wagner DP+EVO III FMIC,ERCP,BMS Intake,Mason Strut Bar,Wedge Tune
Appreciate 2
dtla1813.50
duder13763.00
      07-11-2019, 09:04 PM   #136
Gangplank
Brigadier General
Gangplank's Avatar
United_States
1469
Rep
3,006
Posts

Drives: 2011 e82 135i n55 Sport w/ DCT
Join Date: Nov 2015
Location: Vero Beach, FL

iTrader: (2)

Garage List
2011 135i  [0.00]
Quote:
Originally Posted by AndyW View Post
Upgrade the Rear Subframe Bushings (RSFB). Whiteline makes a decent 2-piece poly set.
This^^ plus a rear differential lockdown bracket really helps too.

Last edited by Gangplank; 07-16-2019 at 09:07 PM..
Appreciate 0
      07-15-2019, 08:07 PM   #137
chicken Legs
New Member
0
Rep
6
Posts

Drives: 2011 space silver 135i
Join Date: May 2018
Location: canada

iTrader: (0)

differential lockdown bracket this I have not seen I'll check it out do springs and shocks help (seen some guys raving about M sport yellow springs and koni shocks) I'm in canada so I don't what my teeth to fall out
Appreciate 0
      07-16-2019, 05:37 PM   #138
deesea
First Lieutenant
Canada
58
Rep
348
Posts

Drives: 2009 135i
Join Date: Jul 2015
Location: Markham, ON

iTrader: (1)

Quote:
Originally Posted by chicken Legs View Post
differential lockdown bracket this I have not seen I'll check it out do springs and shocks help (seen some guys raving about M sport yellow springs and koni shocks) I'm in canada so I don't what my teeth to fall out
Am canadian, also did the works to my e82 as well. If I were to start again, I'd probably grab some Koni yellows, dinan camber plates, stiffer rear strut mounts, and swift spec-r springs to start.

Then do the RSFB, all the M arms and an alignment (again).

If you're budget limited and you've ditched the stock Runflats, just do the RSFB and leave it until you have funds to do more (or if you even want to do more).

Skip the power mods and focus on suspension instead.

Last edited by deesea; 07-16-2019 at 05:43 PM..
Appreciate 0
      07-19-2019, 12:51 PM   #139
chicken Legs
New Member
0
Rep
6
Posts

Drives: 2011 space silver 135i
Join Date: May 2018
Location: canada

iTrader: (0)

I'm running MHD stage 2+ and all the supporting mods for it, adding meth (have everything just need the time) 235/40/18 MPSS 265/35/18 MPSS REAR AND RSFB inserts stock bushing with poly fillers .....yellow vs gold koni for the street ? swift spec r springs vs stock ....find the car moves around too much after hitting bumps .....bump wig-ill bump wig-ill don't what to turn it into a hay wagon.......power is nothing without control!
Appreciate 0
      07-19-2019, 02:11 PM   #140
dtla1
Colonel
dtla1's Avatar
814
Rep
2,241
Posts

Drives: 2011 135i, Space Grey
Join Date: Apr 2014
Location: Silicon Valley

iTrader: (2)

Quote:
Originally Posted by chicken Legs View Post
I'm running MHD stage 2+ and all the supporting mods for it, adding meth (have everything just need the time) 235/40/18 MPSS 265/35/18 MPSS REAR AND RSFB inserts stock bushing with poly fillers .....yellow vs gold koni for the street ? swift spec r springs vs stock ....find the car moves around too much after hitting bumps .....bump wig-ill bump wig-ill don't what to turn it into a hay wagon.......power is nothing without control!
I felt the inserts didn't really do much for me, get replacements. Whiteline 2 piece is on the easier side of DIY install. Other options out there though.
Appreciate 1
duder13763.00
      08-10-2019, 07:02 AM   #141
Angel67
Enlisted Member
Angel67's Avatar
Canada
39
Rep
44
Posts

Drives: E92 335xi
Join Date: Apr 2019
Location: Canada

iTrader: (0)

Hey guys.

We have manufactured rear toe arms for the e82 and e9x non-M. The design principle is a curved arm, but with dimensions better suited to the non-M suspension.

These are made of billet 6061-T6 aluminum and have been precision CNC machined to accept either balljoints or bushings (which can be either stock bushings or much stiffer Group N bushings, or even polyurethane bushings like those from Powerflex and other suppliers), or any combination of balljoints and bushings depending on individual preferences. They can be anodized in any colour. They can also be made either in the standard length (412 mm) or +3 mm for extra toe.

Just trying to gauge interest at this point so please reply if you might be interested in this product.

a

Stay tuned!
Attached Images
 

Last edited by Angel67; 08-10-2019 at 07:11 AM.. Reason: Adding pic
Appreciate 4
Dackelone9877.50
lab_rat284.50
SKI-R116.00
      08-10-2019, 10:24 AM   #142
houtan
Colonel
houtan's Avatar
527
Rep
2,490
Posts

Drives: 2011 135i
Join Date: Jun 2013
Location: socal

iTrader: (15)

Garage List
2011 135i  [5.00]
Do you have any idea of what the price would be?
Appreciate 0
      08-10-2019, 04:27 PM   #143
Angel67
Enlisted Member
Angel67's Avatar
Canada
39
Rep
44
Posts

Drives: E92 335xi
Join Date: Apr 2019
Location: Canada

iTrader: (0)

I have an idea but the prices will also depend on what options are selected. Regular bushings and balljoints would be similar pricing but Group N bushings are more expensive.

But note that balljoints would provide no contribution to wheel rate while regular bushings would provide some contribution (say equivalent to 15 lb/in per bushing) while Group N would contribute by my calculations an equivalent to 56 lb/in per bushing on the toe arm.

That's the really nice thing about these arms - you can select bushings/balljoints/combination and thereby tweak your effective spring rate in increments.

On my car (e92 335xi) we just installed a set with a balljoint on one side of the arms and a Group N bushing on the other side. All 5 of my arms are bushing on one side and balljoint on the other side, like the M3 arms have.
Appreciate 0
      08-10-2019, 05:08 PM   #144
Angel67
Enlisted Member
Angel67's Avatar
Canada
39
Rep
44
Posts

Drives: E92 335xi
Join Date: Apr 2019
Location: Canada

iTrader: (0)

So, for example, on effective spring rates:

- 2 balljoints: 0
- 1 balljoint and 1 regular bushing: 15
- 2 regular bushings: 30
- 1 balljoint and 1 Group N: 56
- 1 regular bushing and 1 Group N: 71
- 2 Group N: 112

Assuming the contribution of a full set of stock bushings is an equivalent of 109 lb/in, then that can be fully compensated with a set of MRP toe arms with 2 Group N bushings, and the other 4 arms can be only balljoints...

a

Stay tuned!
Appreciate 2
lab_rat284.50
Torgus2754.50
      02-20-2020, 02:10 AM   #145
Skotcoop
First Lieutenant
Skotcoop's Avatar
United_States
254
Rep
326
Posts

Drives: G01
Join Date: Jan 2015
Location: Everett

iTrader: (0)

This information has been invaluable. I currently have the Eibach coilover pro kit on order and should be getting them installed along with the Dinan upper shock mounts March 13th. So in the mean time I've been wondering what else would be a good upgrade to do during the coilover install. After reading this, much appreciated by the way, it seems like better options would be swaybars, diff bushings, and maybe subframe bushings? However, as nice as it would be to do all the work at once I'm very tempted to do it piece by piece in order to better identify each components benefit if it exists. Since going from stock to nice coilovers should feel like a huge improvement in all areas. So that's my plan. Thanks again fe1rx for the mildly obsessive and detailed information.
__________________
2010 135i M-sport SOLD
2019 X3 M40i Glacier silver w/cognac
Appreciate 0
      04-16-2020, 03:54 AM   #146
Joao Basso
Registered
Portugal
6
Rep
4
Posts

Drives: 2007 123d
Join Date: Dec 2014
Location: Lisboa, Portugal

iTrader: (0)

Rear Suspension Guide Rod compression spring rate

GUIDE ROD

Attachment 1143090

The Guide Rod and Trailing Arm react thrust and braking loads. A simple analysis of the in-service load levels is impractical due to the sophisticated geometry of the multi-link suspension.

The OE Guide Rod is a pair of pressed steel halves welded together with inboard and outboard rubber bushings. LH and RH parts are identical as the welded assembly is straight. The two halves of the weldment form two parallel columns that fail by buckling away from each other at a load in excess of 14,000 lbs, based on testing. The unit would be stronger if it were fully welded, but the partially welded design provides for controlled failure.

Attachment 1143091

The M3 Guide Rod is forged aluminum with inboard ball joint and outboard rubber bushing. The forged bodies of the LH and RH arms are identical but installation of the bushings makes them handed. The bodies are curved (downward), not for installation clearance issues, but to ensure that the compressive failure of this member will be by progressive bending. The ball joint used at the inboard location effectively doubles the stiffness and halves the deflection under axial loading versus the OE Guide Rod, which will alter (and presumably decrease) compliance steer effects.

Attachment 1143092


Hello,

Thank you for all this info.
Did you toke note of the compression spring rate of the guide rod before it colapsed?

By the way, I believe the reason for the M3 aluminium arms being curved and flexible is to be compatible the over-restrained geometry of the 5 link suspension.

This means that if you make all suspension arms and the subframe solid enough, the suspension would be locked.

In real world terms, if you make all arms solid, the weakest itens in the suspension arrangement would be forced to flex or bend, creating a failure condition after a number of cycles.

There is a reason for most race cars suspension hub being controled by a 3 ball joint arrangement. Because 3 points define a plane with no need for arm flexibility.

So why BMW spend money designing a 5 link suspension? To acomodate toe-in increase only during cornering and braking, and not during bump/rebound suspension movement, to add stability to the car without adding tyre wear and fuel consumption typical of lots of toe-in setup.

Hope this helps

Joao
Appreciate 2
asbrr440.00
SamN0.00
      04-16-2020, 07:33 AM   #147
fe1rx
Captain
1091
Rep
720
Posts

Drives: 135i, 328i, Cayman S
Join Date: Jan 2008
Location: Canada

iTrader: (3)

A suspension upright has six degrees of freedom: vertical translation, lateral translation, longitudinal translation, steering angle change, camber angle change, and caster angle change. The rear suspension must be constrained to a single unique path.

Six fixed length links would prevent all motion. Making only one adjustable (the spring) achieves one unique suspension motion. Making the toe arm adjustable (I.e. making it a tie rod connected to a steering rack) adds the ability to steer the wheel.

A 5-link is not over constrained and works fine with ball joints everywhere - that is what I am currently running.

I did not measure the stiffness of the steel arm itself because it was clear that at operating loads all meaningful deflection came from the bushings.
Appreciate 4
SKI-R116.00
asbrr440.00
ppointer218.50
      04-16-2020, 04:18 PM   #148
Joao Basso
Registered
Portugal
6
Rep
4
Posts

Drives: 2007 123d
Join Date: Dec 2014
Location: Lisboa, Portugal

iTrader: (0)

Hi there,

Thanks for your reply.

What you said made me look closer to the subject and I have to agree with you and your practical experience: this 5 link suspension will not lock if you use ruber joints or ball joints in both extremes of the arms.

However I don't totally agree with your explanation for this.

First of all, we are talking about the suspension upright control. It can not rotate. The wheel rotates because it sits on a roller bearing. The suspension works the same way whenever the wheel rotates or it is stoped.

For the suspension upright, there are 6 degrees of freedom: 3 linear on 3 axles (vertical, lateral and longitudinal) and 3 rotational over the same 3 axles.

2 longitudinal arms stop longitudinal movement and rotation over the lateral axle.
3 lateral arms stop lateral movement and rotation over the longitudinal and vertical axles.
Vertical movement is allowed and controlled by the spring and damper.

Regarding the Guide Rod, the way it is designed it really looks like it would act as a spring together with the rubber joints.
I'm going to strengthen those in my car and see if I lose some mid corner understeer.

Regards

Joao
Appreciate 2
fe1rx1090.50
asbrr440.00
      04-16-2020, 09:03 PM   #149
fe1rx
Captain
1091
Rep
720
Posts

Drives: 135i, 328i, Cayman S
Join Date: Jan 2008
Location: Canada

iTrader: (3)

Quote:
Originally Posted by Joao Basso View Post
Hi there,

Thanks for your reply.

What you said made me look closer to the subject and I have to agree with you and your practical experience: this 5 link suspension will not lock if you use ruber joints or ball joints in both extremes of the arms.

However I don't totally agree with your explanation for this.

First of all, we are talking about the suspension upright control. It can not rotate. The wheel rotates because it sits on a roller bearing. The suspension works the same way whenever the wheel rotates or it is stopped.

Regards

Joao
Yes ...
I have to agree I got that wheel rotation thing wrong. I have edited my post to better (I hope) make my point.
Thanks for keeping me on my toes.
Appreciate 2
asbrr440.00
cwlo70.50
      04-19-2020, 12:54 AM   #150
128ibro
Private First Class
128ibro's Avatar
33
Rep
123
Posts

Drives: 128i Convertible
Join Date: Feb 2018
Location: United States

iTrader: (0)

Quote:
Originally Posted by fe1rx View Post
Questions that have been plaguing me:

1) What exactly are the benefits of the M3 forged aluminum rear suspension arms vs. the 135i pressed steel arms?
2) Given that the upper, guide and toe arms function structurally as struts, which is to say they react only compression and tension loads (with some structurally insignificant bending due to torque in the rubber bushings), why are the M3 forged aluminum arms curved? This is not required for installation clearance and is structurally weaker than a straight arm. (The corresponding 135i steel parts are straight.)

Perhaps some of the answers can be found below:

Attachment 1143083


M3 Rear Suspension Arms

1 – Wheel Carrier (Upright)
4 – Camber Arm
10 – (Semi-)Trailing Arm
13 – Steering Arm (Toe Control Arm)
17 – Wishbone (Upper Arm)
18 – Guide Rod

These members provide the functional equivalent of a double A-arm suspension, with the triangles formed by the two upper arms (green) and the two lower arms (purple) forming two virtual A-arms.

Attachment 1143084

135i Rear Suspension Arms (Looking Outboard)


RUBBER BUSHINGS

The rear suspension is rubber-bushed at the following locations:

- Camber Arm inboard end (pressed into subframe, M3 and 135i)
- Trailing Arm both ends (pressed into subframe and wheel carrier, M3 and 135i)
- Toe Control Arm both ends (135i only)
- Upper Arm outboard end (M3 and 135i)
- Guide Rod (both ends on 135i, outboard end only on M3)

The rubber bushings in the Upper Arm and Guide Rod consist of a steel bushing core and two concentric metal shells, isolated by rubber. The M3 and 135i bushings are functionally identical and stiffness measurements indicate a radial stiffness of approximately 10,000 N/mm. The stiffness is linear in the (assumed) working range of ±3000 lbs (±13000 N), corresponding to a deflection of ±1.3 mm, but becomes progressively stiffer beyond that. Suspension travel causes rotation of the inner core relative to the outer shell (in the axis of the attach bolt), shearing the rubber and contributing to the total spring rate of the suspension. To minimize stress on the rubber core, it is essential that rubber bushed joints are torqued at static ride height. Rotation of the bushing in the other two axes is possible, preventing any binding in the joint.

Attachment 1143085


Bushing Compliance Test (note dial indicator)

Inspection and measurement of 2008 rear suspension arm bushings with 100,000 km service found no sign of deterioration in the rubber bushings; however, the used bushings were approximately 14% stiffer than new M3 rubber bushings, presumably due to aging of the rubber.

Attachment 1143086

Inboard Rubber Bushing / Outboard Rubber Bushing / Inboard Ball Joint

Attachment 1143087

The other rubber bushings used in the suspension at the Camber Arm (inboard end) and the Trailing Arm (both ends) are similar construction, but were not sectioned or measured for stiffness.


BALL JOINTS (Spherical Bearings)

The rear suspension is ball jointed at the following locations:

- Camber Arm outboard end (pressed into wheel carrier, M3 and 135i)
- Toe Control Arm both ends (M3 only)
- Upper Arm inboard end (M3 and 135i)
- M3 Guide Rod inboard end (pressed into arm)

The ball joints consist of a spherical steel inner race and a plastic outer race housed in a mating outer metal shell. In the 135i Upper Arm, the ball joint is a separate assembly, pressed into the arm weldment. Where ball joints are incorporated into the M3 suspension arms, the aluminum forms the housing for the plastic outer race without a separate steel shell. The bearings are permanently assembled by swaging the shell (or aluminum arm) to affix metal end plates that fix the plastic outer race in place. The bearings are permanently lubricated and sealed by rubber boots. The bearing is free to rotate in all axes, so it is not necessary to torque ball-jointed connections at ride height. This construction provides virtually no radial compliance (large radial stiffness).

Inspection and measurement of 2008 rear suspension arm ball joints with 100,000 km service found no sign of wear on the plastic outer race and no detectable radial play in the bearing assemblies.


UPPER ARM

The Upper Arm and the Camber Arm together establish the camber of the rear tire. Under static loading, the Upper Arm is in compression (less than 1000 lbs). Lateral weight transfer and bumps increase the compressive force in this member, but cornering loads on the more highly loaded outer wheel reduce the compressive force in this member.

The OE Upper Arm is pressed steel with inboard ball joint and outboard rubber bushing. LH and RH parts are identical as the pressed steel body is straight. Asymmetrical section ensures that that compressive failure will be by crippling. Ultimate compressive strength of the arm is approximately 9000 lbs, based on static testing. At this load the arm begins to cripple. The failure is progressive and benign.

Attachment 1143088

Upper Arm Test

Attachment 1143089

Upper Arm Crippling Failure

The M3 Upper Arm is forged 6082T6 aluminum with an inboard ball joint and an outboard rubber bushing. The forged bodies of the LH and RH arms are identical but installation of the bushings makes them handed. The bodies are curved (upward), not for installation clearance issues, but to ensure that the compressive failure of this member will be by progressive bending. The ball joint and bushing on this part are nominally equivalent to those in the OE Upper Arm, so installation of the M3 Upper Arm in place of the 135i Upper Arm is unlikely to have any handling benefit (e.g. reduction of compliance steer effects).


GUIDE ROD

Attachment 1143090

The Guide Rod and Trailing Arm react thrust and braking loads. A simple analysis of the in-service load levels is impractical due to the sophisticated geometry of the multi-link suspension.

The OE Guide Rod is a pair of pressed steel halves welded together with inboard and outboard rubber bushings. LH and RH parts are identical as the welded assembly is straight. The two halves of the weldment form two parallel columns that fail by buckling away from each other at a load in excess of 14,000 lbs, based on testing. The unit would be stronger if it were fully welded, but the partially welded design provides for controlled failure.

Attachment 1143091

The M3 Guide Rod is forged aluminum with inboard ball joint and outboard rubber bushing. The forged bodies of the LH and RH arms are identical but installation of the bushings makes them handed. The bodies are curved (downward), not for installation clearance issues, but to ensure that the compressive failure of this member will be by progressive bending. The ball joint used at the inboard location effectively doubles the stiffness and halves the deflection under axial loading versus the OE Guide Rod, which will alter (and presumably decrease) compliance steer effects.

Attachment 1143092

TOE CONTROL ARM

The Toe Control Arm maintains the toe angle and minimizes bump steer over the range of suspension travel. A simple analysis of the in-service load levels is impractical due to the sophisticated geometry of the multi-link suspension, however loads in this member are obviously less than those in the Upper Arm. This member is also designed for progressive crippling failure under compressive overload.

The OE Toe Control Arm is pressed steel with inboard and outboard rubber bushings. LH and RH parts are identical as the body is straight. A reduced section depth at the center of the arm ensures that that compressive failure will be by crippling at this location, and that the failure will take the arm away from conflict with the suspension spring. I have tested the OE toe arm to a compressive load of 2250 lbs without failure or permanent deformation but have not tested this member to failure. Because Toe Control Arm loads are believed to be relatively modest (in comparison to the other suspension arms), deflection in these bushings is likely small, but it will result in dynamic toe changes. The Toe Arm bushings slightly different construction to the rubber bushings in the Upper and Guide members, and they are about 30% stiffer.

Attachment 1143093

The M3 Toe Control Arm is forged aluminum with inboard and outboard ball joints. T LH and RH arms are identical. The bodies are curved (downward), not for installation clearance issues, but to ensure that the compressive failure of this member will be by progressive bending. The ball joints used at both ends of this member virtually eliminate compliance at the bolted connections. It should be noted that the M3 Toe Control Arm is not dimensionally interchangeable with the OE Toe Control Arm due to different overall pin-center lengths. To say it eliminates all compliance in this member is incorrect though, because the curved design turns the member into a spring. Provided the bending stresses are below the yield stress for the material, the compliance is elastic and reasonably linear.

I have tested an M3 Toe Control Arm to compressive failure to verify its strength and failure mode. Ultimate strength approximately 7600 lbs:

Attachment 1143094

Bending in the member is quite obvious as load increases. Beyond this load the deformation becomes permanent, but the bending is evenly distribute along the length of the member, showing that very large deflections will be tolerated before catastrophic failure. The failed arm is sitting on top of an untested arm for comparison.

Attachment 1143095

This testing was motivated by the desire to design and fabricate a ball-jointed toe arm using the same design philosophy as the M3 arm, but with the correct pin-centre geometry for the 135i. I tested a prototype article with some care to accurately measure deflections vs. load.

Attachment 1143096

Testing proceeded to ultimate then the load was removed. The load was then re-applied to produce significant permanent deformation and the load removed. The resulting load vs. deflection graph shows the classic distinction between the areas of elastic and plastic deformation.

Attachment 1143097

This test shows that the prototype toe arm is structurally equivalent to the M3 toe arm.

Aftermarket Toe Control Arms like the Rogue Engineering that use straight members will provide greater stiffness, but they do not provide the same provision for progressive failure under compressive overload and will fail suddenly if they are overloaded.

(SEMI-)TRAILING ARM

The OE and M3 Trailing Arms are identical and ride in identical rubber bushings pressed into the rear subframe and wheel carrier respectively. These parts are pressed steel and are designed to cripple under compressive overload. As BMW describes it, “the semi-trailing arm features crash beading to ensure the fuel tank is not damaged.” Under compressive overload the arm will buckle down and away from the fuel tank. Rigid, symmetrical trailing arms, like those offered by ECS Tuning do not appear to have this feature.

BUSHING WINDUP

All rubber bushing connections should be torqued at ride height so that the bushings are relaxed (unwound) at ride height. Ball joint connections can be torqued at any height as they are free to rotate and do not wind up. Rubber bushing windup contributes to the overall spring rate of the vehicle. With the OE rear suspension configuration, the wheel rate contributed by the rubber bushings is 35 lb/in. This equivalent to a spring rate of 109 lb/in or 19 N/mm (at the rear spring location), so is quite significant to the overall wheel rate of the vehicle.

Changing the Upper Arm from OE to M3 has no effect on wheel rate as both configurations use similar rubber bushings at both ends.

Changing the Guide Rod from OE to M3 removes one rubber bushing and replaces it with a ball joint, resulting in a softening of the suspension.

Installation of a ball-jointed Toe Control Arm (like the Rogue Engineering part) removes two rubber bushings, resulting in a further softening of the suspension.

Assuming the latter two changes are made, the wheel rate contributed by the rubber bushings is reduced to 23 lb/in. This is equivalent to a spring rate of 72 lb/in or 13 N/mm (at the rear spring location). A fully ball-jointed suspension would remove all this wheel rate and would need to be compensated for by a corresponding increase in spring rate.
Great info! we need more people like you here
Appreciate 0
      04-28-2020, 08:24 PM   #151
isN54
New Member
isN54's Avatar
United_States
54
Rep
22
Posts

Drives: 2013 Bmw 335is
Join Date: Apr 2020
Location: Moreno Valley, CA.

iTrader: (0)

Cool M3 Control arm upgrade.

I would imagine that if you're going to do the fronts, you might as well do the rears as well.I just figure it'll all work better together as it is designed to do so. I recently upgraded my suspension and went with the TRW M3 style upgrade control arms through FCP and with the Bilstein B8's. I was only riding on the stock dampers with some Swift lowering springs.
The car feels sooo much better now. Much more planted on the turns.
Appreciate 0
Post 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



All times are GMT -5. The time now is 01:39 AM.




1addicts
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, vBulletin Solutions Inc.
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