M3 Rear Subframe Bushings

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Originally Posted by ASAP

With the pss both the up and down bounce and thr side to side flex exists.

Gotcha. I read the problem going away, didn't catch that it was half the problem.

[ASAP]

I almost feel like the culprit may be the rear bushings on the control arms... That's the only place that I can imagine side to side flex coming from.

[MightyMouseTech]

Did not see anyone else mention this, so I thought I would add.

Just installed the M3 subframe bushings on my own car. One thing both myself and my wife noticed right away was how much better the clutch engagement feels. I have done the CDV delete and the car used to, what felt like, bounce off the bushings when letting out the clutch. It would sort of lurch forward, hit a stop, and bounce back a bit. I am exaggerating the feeling a bit, but that is what it felt like. With the subframe bushings done, the clutch is smooth as butter. Let out the clutch, no lurch, just smooth take off. Makes sense as the subframe is not rocking back and forth when you apply power.

Very happy with this.

I now understand the hive mentality about replacing them. God the stock bushings are horrible. Now the wife can not wait for the next upgrade. She comes home every day now beaming about how much better the car feels.

[ASAP]

Originally Posted by MightyMouseTech

Did not see anyone else mention this, so I thought I would add.

Just installed the M3 subframe bushings on my own car. One thing both myself and my wife noticed right away was how much better the clutch engagement feels. I have done the CDV delete and the car used to, what felt like, bounce off the bushings when letting out the clutch. It would sort of lurch forward, hit a stop, and bounce back a bit. I am exaggerating the feeling a bit, but that is what it felt like. With the subframe bushings done, the clutch is smooth as butter. Let out the clutch, no lurch, just smooth take off. Makes sense as the subframe is not rocking back and forth when you apply power.

Very happy with this.

I now understand the hive mentality about replacing them. God the stock bushings are horrible. Now the wife can not wait for the next upgrade. She comes home every day now beaming about how much better the car feels.

Drive it hard around corners and let me know about any side to side flex.

[MightyMouseTech]

Originally Posted by ASAP

Drive it hard around corners and let me know about any side to side flex.

Will be a while. Still in the deep freeze here and running my 205 Hakka's. But even with with super sloppy winters, it feels MUCH, MUCH better. Although, I did install the M3 rear upper arms at the same time.

You mention you are running PSS tires. What size tire are you running on what size rim? Using a tire too wide for the rim can cause exactly what you are describing, like fitting wider than a 245 on the stock rim.

@ASAP

[brocklanders]

I'm pretty sure a 255 is just fine on a 8.5" wide wheel.

[ASAP]

Originally Posted by MightyMouseTech

Will be a while. Still in the deep freeze here and running my 205 Hakka's. But even with with super sloppy winters, it feels MUCH, MUCH better. Although, I did install the M3 rear upper arms at the same time.

You mention you are running PSS tires. What size tire are you running on what size rim? Using a tire too wide for the rim can cause exactly what you are describing, like fitting wider than a 245 on the stock rim.

@ASAP

Stock size pss on stock rims... setup is getting changed up to wider wheels and tires, I shall report back to see if it helps.

[MightyMouseTech]

What pressures are you running?

[ASAP]

Originally Posted by MightyMouseTech

What pressures are you running?

37 Rear
35 Front

I am sure the issue is deflection of all of the rear control arms and the guide rods.

[chris82]

Originally Posted by brocklanders

I'm pretty sure a 255 is just fine on a 8.5" wide wheel.

Yea it's the minimum width wheel that tire should be on. 255 is usually measured on a 9" wheel, and the range of suitable wheels are from 8.5 - 10 inches. So yea, 255 is fine on 8.5".

[MightyMouseTech]

Originally Posted by ASAP

37 Rear
35 Front

I am sure the issue is deflection of all of the rear control arms and the guide rods.

My car shows minimum pressures are 36 front, 39 rear. Should be close enough.

[Solo_M_Tech]

I just had the dealer install the M3 bushings on my car with the E92 M3 FSB. MASSIVE upgrade. I noticed an immediate difference. Also, as to side to side flex, if there is any, it's tire or control arm related. Once track season gets here, I will have a better comparison to report, since the issues with the stock bushings were OBVIOUS when driving hard on the Nurbergring. Prelimary feelings are exeptional, and I don't think i could be happier with my current set up!

[JRMorgan]

Originally Posted by ASAP

I will say that I am still disappointed in this car and probably will not buy another short chassis car again in my life. The car is incredibly fun to drive, feels like a go cart and its size perfect... now on to the bad -

I have now replaced the tires for Michelin PSS, done the M3 rear subframe bushings, and installed brand new Koni Yellows all around. Does the car feel better than without those upgrades? Sure it does... Does it still not feel right... yes it does.

The car is now planted and stable after the bushings and dampers but it still exhibits excessive front to back lateral movement and side to side shimmy on acceleration. My 335i never did this... the shorter chassis causes problems for this car and that's pretty much that. While, I will say that for about $2k I was able to improve the car and the way it feels in terms of suspension it is still far subpar to a stock 335i... To me that is a problem.

My E90 335i had far more front to back movement and was bouncy compared to the 135i. If there is a disadvantage IMHO I'd say high speed stability isn't as good as the 335i. But acceleration is just fine for me.

[JRMorgan]

Originally Posted by aloksatoor

I have had a 335 with sport suspension before this car and the 335 never felt right to me in stock form. It felt very soft and cumbersome in addition to a harsher ride (even with a longer base) on the RFTs (thats the best I could describe it), it went like a rocket in a straight line but super hard for the tail to break loose as well (felt super planted at speed). The braking was also sub par compared to the 1er.

As others said somethings wrong with the setup on your 1er, did you get a stealership /performance oriented shop alignment done as well? Maybe that would solve your handling issues? I did notice the year of the car as well. Maybe some of the other bushings are tired as well (drivetrain since it shimmies on acceleration or the rear multilink)? That could cause her to be floppy.

My experience matches yours. I would have used the same words. I didn't find it too hard to break the tail but when it did it really broke with less control than the 135i. The planted feeling at speed is really it's major advantage.

[juld0zer]

Bit of a thread revival here but here's my 2c.

- DSC: Are your observations based on driving with DSC on in normal mode, DTC or off?
- Tyres: PSS are crap when they are cold. They need some warmth in them to work.

I've found that some cars work better with certain tyres but the same model tyre on a different car will yield a different experience. To me it seems that our cars are designed around the stock RFTs. The DSC seems to be calibrated based on these tyres, or BMW has a special contract with the tyre manufacturers to produce a tyre specific to BMW's demands - there might be more to the star designation on the tyre.

I managed to score a set of F20 18" wheels shod with 225/40 front and 245/35 rear Bridgestone S001 RFTs for cheap. Approx 80% tread all round. Put them on my car and immediately noticed a couple of things. They struggle to hold traction under hard acceleration, even in dry conditions. Wheelspin and axle tramp is noticeable and the tyres spin enough to screech. This did not happen with my 50% worn rear RE050As. The fronts despite being 10mm wider and with more remaining tread also did not feel as precise as the 215 wide RE050As with 3mm on the outer and inner edges. Pressures same for both sets. The car stays surprisingly straight when accelerating hard from a stop in damp conditions.

I will be switching to non-RFT later but all these observations are based on a stock DCT car with stock suspension and no alignment since i bought it used. It now has Whiteline subframe bushings and the dancing rear over bumpy corners is significantly reduced. Fast lane changes are also a lot less hair raising now. The bushings actually reduced a lot of the boaty feel - the only reason i am planning a suspension upgrade is due to the poor damping over sharp bumps and big speed bumps. Car has 132,000km so the stock shocks are probably tired despite not leaking any oil

[encarozador]

Hello there! I have an E81 123d and I'd ask you if someone have done the M3 rear subframe bushings upgrade on a Diesel model, due to the reference of the rear bushings is different on diesel models respect petrol models. Thank you!

[goldcoastci]

good！ thanks for sharing!