Another solid bushing install at MRF

[Bx Tpr]

Any close up pictures of the mounting points after the subframe is installed with the solid bushings?

[Beedub]

MRF do you have any that are suitable for the z4m??

[JEllis]

Originally Posted by Bx Tpr

Any close up pictures of the mounting points after the subframe is installed with the solid bushings?

Sorry no but not much to see once in the car.

[Bx Tpr]

Originally Posted by JEllis

Sorry no but not much to see once in the car.

Thanks. I was wondering what exactly contacts the chassis of the car with the new bushings? Bushings only/bushing and part of subframe? Looking at the pictures it looks like the top part of the bushing is flush with the top part of the mounting hole in the subframe.

[Exclusivs]

Great Upgrade

[klammer]

I second the subframe bushings. Replaced over a year ago, multiple cross country trips, great solid feel, and as stated earlier, ZERO increase in NVH.

[JEllis]

Originally Posted by Bx Tpr

Thanks. I was wondering what exactly contacts the chassis of the car with the new bushings? Bushings only/bushing and part of subframe? Looking at the pictures it looks like the top part of the bushing is flush with the top part of the mounting hole in the subframe.

There is a small gap between the subframe and unibody just like OEM.

[Superfly_M3]

zero NVH? how can that be? there is no isolation like the factory ones.

This sounds a great mod, but I am skeptical that there is zero NVH. Thanks for posting though.

[JEllis]

Originally Posted by Superfly_M3

zero NVH? how can that be? there is no isolation like the factory ones.

This sounds a great mod, but I am skeptical that there is zero NVH. Thanks for posting though.

No NVH from the subframe bushings. The solid diff bushings do have a little NVH.

If anyone is thinking about a new M car, you are getting solid subframes.

[TXmtrhed]

Originally Posted by mlhj83

How are the Turner solid alu subframe bushes pressed into the subframe?

Also, what is preventing the subframe from slipping upwards i.e. the alu bushes do not appear to have upper rims/collars that prevent the subframe from slipping upwards.

Thanks.

The weight of the car is held up by the springs. Essentially, compressing the springs attempts to pull the subframe away from the car. That's the reason to minimize the deflection so that the shocks and springs can be tuned to control the movement of the wheel alone. Replacing the lower control arm bushings with bearings (e.g. from BW) would help also.

[mlhj83]

Yes, I understand the pivot effect of the rear springs in pulling the subframe downwards, but that isn't an effective way to hold the subframe in place especially when the suspension is quickly loaded and unloaded, like when going over a sharp crest or a dip in the road at speed.

[W///]

Originally Posted by klammer

I second the subframe bushings. Replaced over a year ago, multiple cross country trips, great solid feel, and as stated earlier, ZERO increase in NVH.

Did you change your diff bushings as well?

[Malek@MRF]

Originally Posted by Superfly_M3

zero NVH? how can that be? there is no isolation like the factory ones.

This sounds a great mod, but I am skeptical that there is zero NVH. Thanks for posting though.

No need to be skeptical, however I do understand where it stems from. For years it has been preached that Solid S/F bushings will increase NVH, but this has also come greatly from hearsay and was never true. Intuitively we would also think that NVH will increase since rubber is being removed and replaced with forged Aluminum, however that is not true. The front S/F is also solid mounted to the chassis and this unit deals with engine vibration as well as well as suspension loads.

Yes, changing the differential bushings to solid will increase some noise, but not "vibration" or "harshness". There is no reason for vibration to increase as the differential that has been unitized is not vibrating, unless something is out of balancing with the half shafts or propeller shaft itself creating harmonic vibration.

[Beedub]

Originally Posted by Malek@MRF

No need to be skeptical, however I do understand where it stems from. For years it has been preached that Solid S/F bushings will increase NVH, but this has also come greatly from hearsay and was never true. Intuitively we would also think that NVH will increase since rubber is being removed and replaced with forged Aluminum, however that is not true. The front S/F is also solid mounted to the chassis and this unit deals with engine vibration as well as well as suspension loads.

Yes, changing the differential bushings to solid will increase some noise, but not "vibration" or "harshness". There is no reason for vibration to increase as the differential that has been unitized is not vibrating, unless something is out of balancing with the half shafts or propeller shaft itself creating harmonic vibration.

am i invisible or something???

do you do these for the e46 m3 / z4m platform.

[Malek@MRF]

Originally Posted by Beedub

am i invisible or something???

do you do these for the e46 m3 / z4m platform.

I am sorry. These bushings are for E9x platform cars only (M and non M vehicles).

I will be releasing E46 M3 S/F mounts in a similar fashion as the E9x units as well as I have been seeing demand for solid units over the urethane parts.

[Beedub]

Originally Posted by Pertplus

Dude just PM him....and yes, you're invisible.

prick

[Beedub]

Originally Posted by Malek@MRF

I am sorry. These bushings are for E9x platform cars only (M and non M vehicles).

I will be releasing E46 M3 S/F mounts in a similar fashion as the E9x units as well as I have been seeing demand for solid units over the urethane parts.

thankyou

[JEllis]

Originally Posted by mlhj83

Yes, I understand the pivot effect of the rear springs in pulling the subframe downwards, but that isn't an effective way to hold the subframe in place especially when the suspension is quickly loaded and unloaded, like when going over a sharp crest or a dip in the road at speed.

The bushes are pressed into the subframe in a basically identical fashion to OEM. I am not sure how much pressure is required to move the bushes but it is far more than what the weight of the car can apply.

Keep in mind the aluminum bushes hold the subframe the same as the stock rubber bushes. The difference is that the aluminum bushes will not wear over time and allow the subframe movement you are concerned about.

[mlhj83]

Originally Posted by JEllis

The bushes are pressed into the subframe in a basically identical fashion to OEM. I am not sure how much pressure is required to move the bushes but it is far more than what the weight of the car can apply.

Keep in mind the aluminum bushes hold the subframe the same as the stock rubber bushes. The difference is that the aluminum bushes will not wear over time and allow the subframe movement you are concerned about.

Thanks, I understood your first reply - was just replying to another poster.

[aajami]

Originally Posted by Malek@MRF

No need to be skeptical, however I do understand where it stems from. For years it has been preached that Solid S/F bushings will increase NVH, but this has also come greatly from hearsay and was never true. Intuitively we would also think that NVH will increase since rubber is being removed and replaced with forged Aluminum, however that is not true. The front S/F is also solid mounted to the chassis and this unit deals with engine vibration as well as well as suspension loads.

Yes, changing the differential bushings to solid will increase some noise, but not "vibration" or "harshness". There is no reason for vibration to increase as the differential that has been unitized is not vibrating, unless something is out of balancing with the half shafts or propeller shaft itself creating harmonic vibration.

Hi Malek,

What are your thoughts on changing the subframe bushings but keeping the stock differential bushing intact for street driving? Any increase in noise, especially a whine, is going to be off-putting.

[Malek@MRF]

Originally Posted by aajami

Hi Malek,

What are your thoughts on changing the subframe bushings but keeping the stock differential bushing intact for street driving? Any increase in noise, especially a whine, is going to be off-putting.

I have done this for a few cars now. It is an excellent upgrade without exhibiting any form of NVH or whine from the differential. I can 100% guarantee that changing the S/F bushings will not increase NVH by any noticeable or measurable degree.

One of my customers, Pertplus opted for this route, and much like you, he wanted the car to be setup correctly, perform well and provide rear end stability without NVH as the car is only street driven.

The sub-frame bushings provide the following benefits:
- zero deflection of the frame
- zero possibility of tearing the mounts
- maintains alignment geometry, since the frame cannot shift laterally or longitudinally.
- increased traction
- more power applied to the wheels (energy transfer efficiency is increased)
- drastically reduced wheel hop (wheel hop can be eliminated when combined with the differential bushings as well as changing out the lower control arm bushings)

[Hujan]

Originally Posted by Malek@MRF

- drastically reduced wheel hop (wheel hop can be eliminated when combined with the differential bushings as well as changing out the lower control arm bushings)

Like these?

http://www.dinancars.com/products/M-...oball-Kit.aspx

Also, out of curiosity, you talked about the drawbacks of replacing the differential bushings, but what are the benefits of doing so for a DCT car? The benefits of the subframe bushings seem obvious to me, but what should we be looking for with the differential bushings?