Good Suspension-basics link

3liter1 · 12-07-2011, 05:39 PM

I searched and did not see any posts here to this, so here is something that I hope you all find interesting !.....

http://www.trackpedia.com/wiki/Suspension

As an aside, I am still doing research on whether changing the subframe bushings would be a positive or negative on the uneven highways here in the northeast. Certainly for track use they make sense, but I'm not so sure for handling the undulations (that I never "knew" existed on highways before putting in the coilovers). Despite many posts I have read here, in discussions I've had with local experts shops, they indicate that making the suspension in any way stiffer will just cause more transmission of the uneven road surfaces as motion to the body. What I read in the link seems to support that view

fboutlaw · 12-07-2011, 06:53 PM

If you're contemplating subframe bushings, do it.

I grew up in the east PA. Potholes suck. Your bushings will not save you from a pothole.

The real difference between the stock bushings and the m3 ones is not the stiffness, it's the core or rubber joining the two parts together. The stock bushings have an inner ring of rubber, an outer ring of rubber and 4 rubber links between the inner and outer cores. The stock bushings will work properly when a load is applied front/back, left/right, but not at any angle that is not perfectly perpendicular or parallel to the orientation of the bushing (90 degree increments). There is essentially zero support to keep the subframe from moving related to the frame in those directions. Thus allowing the inner ring to move significantly in the outer ring of rubber in the bushing. The M3 bushings a lot of us have been swapping are solid cores of rubber. They provide appropriate cushioning in any direction and the subframe is constrained in all dimensions to the body. This provides significantly higher feeling of control as the subframe is now connected to your butt dyno and cant move freely in certain directions that vary by the orientation by which your bushings were installed. Think of it this way, the inner circle of rubber can no longer move freely and always wants to stay centered in the outer circle. This will actually prolong the useful life of your suspension components as they no longer have to account for the extreme angles the stock suspension allowed. Your shocks and springs which also connect between the frame and subframe will be positioned closer to their neutral position and always move up/down.

In short answer, do the change. Your suspension will actually thank you.

GaryS · 12-07-2011, 07:02 PM

In my opinion, there is no way the same person could prefer TC Kline springs & dampers to stock but not prefer M3 rear subframe bushings to stock.

adding: To be clear, I think you should either convert to M3 bushings or put the stock springs back on.

3liter1 · 12-08-2011, 08:15 PM

Quote:

Originally Posted by GaryS

In my opinion, there is no way the same person could prefer TC Kline springs & dampers to stock but not prefer M3 rear subframe bushings to stock.

adding: To be clear, I think you should either convert to M3 bushings or put the stock springs back on.

GaryS:
Well, that's not really helpful. Aa a point of reference, i run in advanced groups at driving schools. I relish passing beginner drivers in their porsche. GT3s and Nissan GTRs. I understand tradeoffs betweem track and street. I know the M3 bushings would be a huge benefit on the track. I am not yet convinced that it is worth spending over a thousand dollars to swap bushings based on the research I've done so far. I am OK with the street ride, but as a typical 1addict, I obsess over that last incremental enhancment. I would gladly experiment and give the M3 bushings a try, if it was a $200 price tag
Can you provide a more detailed before and after explanation?
i looked through your old posts, but did not find anything

3liter1 · 12-08-2011, 08:28 PM

In short answer, do the change. Your suspension will actually thank you.[/QUOTE]

This makes sense to me on the track. As far as street use, here is another way to think about it(not my original thought). Many race setups run 1000 lb spring rates. If you were to run this setup on a highway with any uneven surface at any high speed, you would literally be bounced off the road.Even/especially with racing bushings.

So, I've read numerous posts on how the M3 subframe bushings eliminate "bounce", but not clear that this is an observation of track or autocross dynamics, wherethe suspension is reacting under a full load, as opposed to the lower load experienced just going over uneven road surfaces.

chachacha28 · 12-08-2011, 11:28 PM

are we talking about the bushings that cost $270 on hpashop? where is the $1000 price tag coming from?

delta-9-ginseng · 12-08-2011, 11:43 PM

what are these m3 bushings people talk about? and where can i cop some haha

b/c I totally do feel the bounce in the rear.

Any links?

3liter1 · 12-09-2011, 08:21 PM

I spoke to Eric who was involved in the work they did that was reported in the Bimmerworld article. Eric is happy to speak to anyone with questions.He is at the Ohio location. He reported that the issues they found with the bushings were encountered in situations where the rear suspension is under load, especially when putting on power on corner exits. He also mentioned that the shortcoming was more evident when they tested the 135, which has more power. My concern was more in terms of the suspensions ability to attenuate "bounce" at a constant velocity over uneven road surfaces (not potholes). He felt this would not be improved by stiffer subframe bushings. Rather he suggested adjusting the rebound rate of the damper in 1/4 turn increments.
So in summary, I want to put the word out to make sure that those considering this change do so with full information as to where the benefits will really be

3liter1 · 12-09-2011, 08:22 PM

Quote:

Originally Posted by ezeedee

are we talking about the bushings that cost $270 on hpashop? where is the $1000 price tag coming from?

at least 5 hours of installation

szcyxzh · 12-09-2011, 09:10 PM

Quote:

Originally Posted by AudiS4

I spoke to Eric who was involved in the work they did that was reported in the Bimmerworld article. Eric is happy to speak to anyone with questions.He is at the Ohio location. He reported that the issues they found with the bushings were encountered in situations where the rear suspension is under load, especially when putting on power on corner exits. He also mentioned that the shortcoming was more evident when they tested the 135, which has more power. My concern was more in terms of the suspensions ability to attenuate "bounce" at a constant velocity over uneven road surfaces (not potholes). He felt this would not be improved by stiffer subframe bushings. Rather he suggested adjusting the rebound rate of the damper in 1/4 turn increments.
So in summary, I want to put the word out to make sure that those considering this change do so with full information as to where the benefits will really be

Good info. In my opinion, any real enthusiast / track addicts should get 1 1///m or wait for M2. More than 4k on 128/135's suspension work is really spoiled.

mike the snake · 12-10-2011, 06:48 PM

The M3 bushings really REALLY make a difference. If you drive spiritedly, as I do on my local backroads, or track your car at all, then you'll appreciate the bushing swap. When the car is "set" in a hard, fast turn, the stock bushings have the rear end bouncing and wiggling around, very unsettling. I felt unsafe driving my car fast, especially on bumpy backroads. The back end is basically all over the place. The stock bushings also allowed the rear suspension to shudder after hitting potholes, manhole covers,, anything that was harsh caused the rear to shudder, and this was very uncomfortable.

Especially if you use stiffer springs and coilovers, you need the M3 bushings, as then the forces are more transmitted to the bushings before the suspension begins to work, and the back end gets even more bouncy.

I was really unhappy with my 135 suspension when I first got it. A new sports car shouldn't feel this way, but after installing the M3 bushings and coilovers/springs I am very much enjoying my 135 much more now.

3liter1 · 12-12-2011, 09:31 AM

Quote:

Originally Posted by mike the snake

The M3 bushings really REALLY make a difference. If you drive spiritedly, as I do on my local backroads, or track your car at all, then you'll appreciate the bushing swap. When the car is "set" in a hard, fast turn, the stock bushings have the rear end bouncing and wiggling around, very unsettling. I felt unsafe driving my car fast, especially on bumpy backroads. The back end is basically all over the place. The stock bushings also allowed the rear suspension to shudder after hitting potholes, manhole covers,, anything that was harsh caused the rear to shudder, and this was very uncomfortable.

Especially if you use stiffer springs and coilovers, you need the M3 bushings, as then the forces are more transmitted to the bushings before the suspension begins to work, and the back end gets even more bouncy.

I was really unhappy with my 135 suspension when I first got it. A new sports car shouldn't feel this way, but after installing the M3 bushings and coilovers/springs I am very much enjoying my 135 much more now.

This makes sense to me. I will see after a track day in the spring.

chachacha28 · 12-12-2011, 09:42 AM

Quote:

Originally Posted by szcyxzh

Good info. In my opinion, any real enthusiast / track addicts should get 1 1///m or wait for M2. More than 4k on 128/135's suspension work is really spoiled.

i disagree. i bought my car used, its easier for me to justify 10 grand in mods, than to buy a newer car for 30 grand more. especially when i will be able to run laps around the newer car.

then again, priorities are going to depend on the person.

szcyxzh · 12-12-2011, 10:01 AM

Quote:

Originally Posted by ezeedee

i disagree. i bought my car used, its easier for me to justify 10 grand in mods, than to buy a newer car for 30 grand more. especially when i will be able to run laps around the newer car.

then again, priorities are going to depend on the person.

Yep, i heard from a German that 1///m is way over priced in your country after tax.

have fun with this cute baby.

chachacha28 · 12-12-2011, 10:03 AM

Quote:

Originally Posted by szcyxzh

Yep, i heard from a German that 1///m is way over priced in your country after tax.

have fun with this cute baby.

im american, im just stationed here. i got a sweet ass deal on my car though.

szcyxzh · 12-12-2011, 10:08 AM

Quote:

Originally Posted by ezeedee

im american, im just stationed here. i got a sweet ass deal on my car though.

ok, fellow. be safe back to home!

12-07-2011, 05:39 PM	#1
3liter1 First Lieutenant 57 Rep 376 Posts Drives: 2019 X3 Join Date: Aug 2008 Location: Northern NJ iTrader: (1)	Good Suspension-basics link I searched and did not see any posts here to this, so here is something that I hope you all find interesting !..... http://www.trackpedia.com/wiki/Suspension As an aside, I am still doing research on whether changing the subframe bushings would be a positive or negative on the uneven highways here in the northeast. Certainly for track use they make sense, but I'm not so sure for handling the undulations (that I never "knew" existed on highways before putting in the coilovers). Despite many posts I have read here, in discussions I've had with local experts shops, they indicate that making the suspension in any way stiffer will just cause more transmission of the uneven road surfaces as motion to the body. What I read in the link seems to support that view __________________ 2018 M3 Alpine White -gone 2009 128i Auto -gone 2014 128 grand coupe - gone
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12-07-2011, 06:53 PM	#2
fboutlaw Cone Cruncher 31 Rep 534 Posts Drives: Dinan 135i Join Date: Apr 2010 Location: Cupertino, CA iTrader: (3)	If you're contemplating subframe bushings, do it. I grew up in the east PA. Potholes suck. Your bushings will not save you from a pothole. The real difference between the stock bushings and the m3 ones is not the stiffness, it's the core or rubber joining the two parts together. The stock bushings have an inner ring of rubber, an outer ring of rubber and 4 rubber links between the inner and outer cores. The stock bushings will work properly when a load is applied front/back, left/right, but not at any angle that is not perfectly perpendicular or parallel to the orientation of the bushing (90 degree increments). There is essentially zero support to keep the subframe from moving related to the frame in those directions. Thus allowing the inner ring to move significantly in the outer ring of rubber in the bushing. The M3 bushings a lot of us have been swapping are solid cores of rubber. They provide appropriate cushioning in any direction and the subframe is constrained in all dimensions to the body. This provides significantly higher feeling of control as the subframe is now connected to your butt dyno and cant move freely in certain directions that vary by the orientation by which your bushings were installed. Think of it this way, the inner circle of rubber can no longer move freely and always wants to stay centered in the outer circle. This will actually prolong the useful life of your suspension components as they no longer have to account for the extreme angles the stock suspension allowed. Your shocks and springs which also connect between the frame and subframe will be positioned closer to their neutral position and always move up/down. In short answer, do the change. Your suspension will actually thank you.
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12-07-2011, 07:02 PM	#3
GaryS Colonel 37 Rep 2,084 Posts Drives: 2009 135i 6MT Join Date: Feb 2010 Location: Maryland iTrader: (0) Garage List 2009 135i [6.50]	In my opinion, there is no way the same person could prefer TC Kline springs & dampers to stock but not prefer M3 rear subframe bushings to stock. adding: To be clear, I think you should either convert to M3 bushings or put the stock springs back on.
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12-08-2011, 08:28 PM	#5
3liter1 First Lieutenant 57 Rep 376 Posts Drives: 2019 X3 Join Date: Aug 2008 Location: Northern NJ iTrader: (1)	In short answer, do the change. Your suspension will actually thank you.[/QUOTE] This makes sense to me on the track. As far as street use, here is another way to think about it(not my original thought). Many race setups run 1000 lb spring rates. If you were to run this setup on a highway with any uneven surface at any high speed, you would literally be bounced off the road.Even/especially with racing bushings. So, I've read numerous posts on how the M3 subframe bushings eliminate "bounce", but not clear that this is an observation of track or autocross dynamics, wherethe suspension is reacting under a full load, as opposed to the lower load experienced just going over uneven road surfaces. __________________ 2018 M3 Alpine White -gone 2009 128i Auto -gone 2014 128 grand coupe - gone Last edited by 3liter1; 12-08-2011 at 08:31 PM.. Reason: typo
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12-08-2011, 11:28 PM	#6
chachacha28 NCOIC of Kickin It 78 Rep 946 Posts Drives: 08 135i "Simona" Join Date: Feb 2011 Location: Great Falls MT iTrader: (1)	are we talking about the bushings that cost $270 on hpashop? where is the $1000 price tag coming from?
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12-08-2011, 11:43 PM	#7
delta-9-ginseng OG Tray Deee 82 Rep 261 Posts Drives: BMW 135i & F36 435i Join Date: Jul 2011 Location: LA and SF iTrader: (0)	what are these m3 bushings people talk about? and where can i cop some haha b/c I totally do feel the bounce in the rear. Any links?
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12-09-2011, 08:21 PM	#8
3liter1 First Lieutenant 57 Rep 376 Posts Drives: 2019 X3 Join Date: Aug 2008 Location: Northern NJ iTrader: (1)	I called TC KLine about the bushings I spoke to Eric who was involved in the work they did that was reported in the Bimmerworld article. Eric is happy to speak to anyone with questions.He is at the Ohio location. He reported that the issues they found with the bushings were encountered in situations where the rear suspension is under load, especially when putting on power on corner exits. He also mentioned that the shortcoming was more evident when they tested the 135, which has more power. My concern was more in terms of the suspensions ability to attenuate "bounce" at a constant velocity over uneven road surfaces (not potholes). He felt this would not be improved by stiffer subframe bushings. Rather he suggested adjusting the rebound rate of the damper in 1/4 turn increments. So in summary, I want to put the word out to make sure that those considering this change do so with full information as to where the benefits will really be __________________ 2018 M3 Alpine White -gone 2009 128i Auto -gone 2014 128 grand coupe - gone
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12-10-2011, 06:48 PM	#11
mike the snake Captain 68 Rep 643 Posts Drives: 135i Join Date: Sep 2011 Location: Sonoma County, CA. iTrader: (1)	The M3 bushings really REALLY make a difference. If you drive spiritedly, as I do on my local backroads, or track your car at all, then you'll appreciate the bushing swap. When the car is "set" in a hard, fast turn, the stock bushings have the rear end bouncing and wiggling around, very unsettling. I felt unsafe driving my car fast, especially on bumpy backroads. The back end is basically all over the place. The stock bushings also allowed the rear suspension to shudder after hitting potholes, manhole covers,, anything that was harsh caused the rear to shudder, and this was very uncomfortable. Especially if you use stiffer springs and coilovers, you need the M3 bushings, as then the forces are more transmitted to the bushings before the suspension begins to work, and the back end gets even more bouncy. I was really unhappy with my 135 suspension when I first got it. A new sports car shouldn't feel this way, but after installing the M3 bushings and coilovers/springs I am very much enjoying my 135 much more now.
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