[Yozh]

Tried to search and came to conclusion that there is no consensus which way to go. Some use inserts, but with OEM bushes and some use M3 replacements. I realize that solid aluminum or delrin/aluminum would be a better performance choice, but I do not feel like yanking the subframe altogether.

Opinions, suggestions, experiences - all welcome, and thank you.

Edit: added solid aluminum ref to the title

[Tom Droze]

Originally Posted by Yozh

Tried to search and came to conclusion that there is no consensus which way to go. Some use inserts, but with OEM bushes and some use M3 replacements. I realize that solid aluminum or delrin/aluminum would be a better performance choice, but I do not feel like yanking the subframe altogether.

Opinions, suggestions, experiences - all welcome, and thank you.

M3 bushings or delrin/aluminum bushings would provide the best improvement in handling, as compared to stock or inserts. However, given the cost and the ease of installation, the subframe bushing inserts are a very good option and they will provide a noticeable improvement. You can buy the inserts for about $60 and the installation will take about 1 1/2 hours or less in your garage. What do you have to lose? If you don't like the result, then you know dropping the subframe and installing bushings are in your future.

[shnaggs]

Originally Posted by Yozh

Tried to search and came to conclusion that there is no consensus which way to go. Some use inserts, but with OEM bushes and some use M3 replacements. I realize that solid aluminum or delrin/aluminum would be a better performance choice, but I do not feel like yanking the subframe altogether.

Opinions, suggestions, experiences - all welcome, and thank you.

Just FYI Yozh, the D takes different inserts than the standard 335's. I could only find them from powerflex.

[Yozh]

Originally Posted by Tom Droze

If you don't like the result, then you know dropping the subframe and installing bushings are in your future.

I do not mind dropping the subframe to do the M3 bushes, it's removing the whole thing to press in the aluminum ones that I am not that fond of. If the difference is so dramatic, then may be it's worth it. Doubt I will find anyone who had compared both on the same car.

Originally Posted by shnaggs

Just FYI Yozh, the D takes different inserts than the standard 335's. I could only find them from powerflex.

It is very curious, because the bushings are the same.

[shnaggs]

They shouldn't be the same. If I recall they are the same as the 1 series

[feuer]

Originally Posted by shnaggs

Just FYI Yozh, the D takes different inserts than the standard 335's. I could only find them from powerflex.

2 are the same 2 are different

Originally Posted by Yozh

It is very curious, because the bushings are the same.

I believe some e91 models also have different subframe bushings

Originally Posted by shnaggs

They shouldn't be the same. If I recall they are the same as the 1 series

I think 1 series has the same bushings as regular non diesel e90/92/93

[chris82]

M3 all the way

[Red_Bean_Bun]

Inserts are a short term solution. Go with the m3 bushes ...

[shnaggs]

Originally Posted by Red_Bean_Bun

Inserts are a short term solution. Go with the m3 bushes ...

Is the nvh really loud with m3's??? I have the black powerflex inserts for my 335d, and the noise under any kinda acceleration is pretty obnoxious.

[Yozh]

Thanks for the feedback. I have checked and yes the rear ones are different. Now, I wonder if they will fit. Suppose I shall check in the appropriate subforum, unless someone here can confirm.

[sukutash]

Yozh,

I did my RSFB a while back and went with the aluminum ones from turner motorsport. I highly recommend them as they transformed how the rear end behaved totally under all conditions. I just recommend that you use this tool http://www.hpashop.com/Bushing-Tool-...g-tool-kit.htm it will make life so much easier. You do not have to remove the subframe completely. Just disconnect the rubber brake lines, 2 of them, that go from subframe to the underbody of the car, seal them so you loose minimal fluid and this will allow you enough room to do the job. I tilted the subframe front or back to gain additional clearance depending on which RSFB I was working on.

[Red_Bean_Bun]

Originally Posted by shnaggs

Is the nvh really loud with m3's??? I have the black powerflex inserts for my 335d, and the noise under any kinda acceleration is pretty obnoxious.

From what I know - the M3 bushings does not have a lot of NVH.

[PrematureApex]

Originally Posted by shnaggs

Is the nvh really loud with m3's??? I have the black powerflex inserts for my 335d, and the noise under any kinda acceleration is pretty obnoxious.

That's something else is up.

Absolutely ZERO added NVH from polys in either of my 135 or X1, nor the vast majority of other members' cars. Not even a hint, nor should there be.

[cpie168]

Originally Posted by PrematureApex

That's something else is up.

Absolutely ZERO added NVH from polys in either of my 135 or X1, nor the vast majority of other members' cars. Not even a hint, nor should there be.

Not trying to challenge you or anything, but I'm just curious as to the reason why those solid bushings don't come standard from the factory if they're so good performance-wise with no sacrifice to NVH. Are they that much more expensive? What about solid rubber ones?

[PrematureApex]

Originally Posted by cpie168

Not trying to challenge you or anything, but I'm just curious as to the reason why those solid bushings don't come standard from the factory if they're so good performance-wise with no sacrifice to NVH. Are they that much more expensive? What about solid rubber ones?

I didn't say solid bushings. I said polyurethane. Rarely do OEMs use poly bushings. More prone to noise, more expensive to produce in bulk, etc. Perhaps wear more quickly without adequate/lasting lubrication.

I'm only saying, based on my experience, and that of my discerning wife, and mother, and that of countless other people, subframe bushings simply do not add a noticeable amount of NVH to these cars.

Why did BMW pick such a shit rubber bushing stock?

I have no idea.

Ask them why an E36 or E46 both rides and handles so comparatively well vs. E90s or F series cars stock to stock, without resorting to laughably soft bushings everywhere.

We're all lost on the rationale.

If you haven't noticed, we're all on here trying to figure out how to fix it.

I'm just promising you, if you swap your OE subframe bushings out for polys, you have 10000000% no worries about an appreciable increases in NVH. It simply isn't there. Any search on the subject will bear that out.

[Yozh]

Originally Posted by sukutash

Yozh,

I did my RSFB a while back and went with the aluminum ones from turner motorsport. I highly recommend them as they transformed how the rear end behaved totally under all conditions. I just recommend that you use this tool http://www.hpashop.com/Bushing-Tool-...g-tool-kit.htm it will make life so much easier. You do not have to remove the subframe completely. Just disconnect the rubber brake lines, 2 of them, that go from subframe to the underbody of the car, seal them so you loose minimal fluid and this will allow you enough room to do the job. I tilted the subframe front or back to gain additional clearance depending on which RSFB I was working on.

Guys, thanks, really. Turner solid aluminum is really my optimum choice. Will still need to figure out if it will fit the 335d rear positions. But what I understood is that one needs to completely drop the subframe and shop press them in.

In all the references that I had found previously, that was the sentiment:

http://www.e90post.com/forums/showthread.php?t=1135362

http://www.e90post.com/forums/showthread.php?t=1118656

http://www.e90post.com/forums/showthread.php?t=1125661

But then again, it seems that no one had done it themselves and had always paid a professional to do it. One individual even mentioned that the mechanic had broken two sets of tools to press the bushings into the subframe. I am fairly mechanically inclined and probably will end up going to a buddy's machine shop with a lift to do it, but really do not want to completely remove the whole subframe.

Sukutash, have you done these yourself using hand tools and if so, can you please provide more details on the process. Also, I see you have the 335d as well, so the Turner Solid Aluminum ones did fit, eh? Thanks.

Btw, concerning the NVH issues. The three threads referenced above basically do confirm that there is no additional NVH even with the solid subframe bushings. Differential bushings are a different story.

[Yozh]

Originally Posted by PrematureApex

Why did BMW pick such a shit rubber bushing stock?

I have no idea.

Probably the same reason they use foam for the rear upper shock mounts...

Run Flats...

[shnaggs]

Originally Posted by PrematureApex

That's something else is up.

Absolutely ZERO added NVH from polys in either of my 135 or X1, nor the vast majority of other members' cars. Not even a hint, nor should there be.

Well this is a little disheartening. I had a dramatic increase to (nvh?) I'll say driveline noise, when I installed subframe inserts in my e90 335d. Only noticeable under light-heavy acceleration and loudness increases with more aggressive throttle input. When car is rolling without throttle input there is no noise. Hope this isn't a sign of something prematurely failing?!?!

Oh, and car has 47k miles on it.

[PrematureApex]

OP:

The install process for inserts vs. two piece polys isn't that much different. You don't have to completely drop the subframe. Just lower it enough on a jack to fit a large socket between the frame and the bushing to use as a pusher when you use heat to remove the old bushings.

[PrematureApex]

Originally Posted by shnaggs

Well this is a little disheartening. I had a dramatic increase to (nvh?) I'll say driveline noise, when I installed subframe inserts in my e90 335d. Only noticeable under light-heavy acceleration and loudness increases with more aggressive throttle input. When car is rolling without throttle input there is no noise. Hope this isn't a sign of something prematurely failing?!?!

Oh, and car has 47k miles on it.

Inserts only? Yes, you 1000% have other issues. I ran inserts at first. Besides a slight reduction in motion in the rear when cornering, you'd have zero idea they were there. Same with full bushing upgrades which were done later, on multiple cars, for multiple people.

You clearly have another issue. Throttle dependent noise? And you think it subframe bushings?

[shnaggs]

Yes throttle dependent. I only was blaming the inserts cause the noise started right after I installed the subframe inserts.

Pretty straight forward install, not sure how I could have effed it up?

I still have stock run flats on the car. Do you think that maybe the tires are super loud and I'm just noticing it with the inserts installed, making it more noticeable? I know I'm grasping at straws.

[sukutash]

Originally Posted by Yozh

Guys, thanks, really. Turner solid aluminum is really my optimum choice. Will still need to figure out if it will fit the 335d rear positions. But what I understood is that one needs to completely drop the subframe and shop press them in.

In all the references that I had found previously, that was the sentiment:

http://www.e90post.com/forums/showthread.php?t=1135362

http://www.e90post.com/forums/showthread.php?t=1118656

http://www.e90post.com/forums/showthread.php?t=1125661

But then again, it seems that no one had done it themselves and had always paid a professional to do it. One individual even mentioned that the mechanic had broken two sets of tools to press the bushings into the subframe. I am fairly mechanically inclined and probably will end up going to a buddy's machine shop with a lift to do it, but really do not want to completely remove the whole subframe.

Sukutash, have you done these yourself using hand tools and if so, can you please provide more details on the process. Also, I see you have the 335d as well, so the Turner Solid Aluminum ones did fit, eh? Thanks.

Btw, concerning the NVH issues. The three threads referenced above basically do confirm that there is no additional NVH even with the solid subframe bushings. Differential bushings are a different story.

I did the install myself with home made press tools. I used a 3" pipe coupling with a huge assortment of hard steel/tooling washers, at least 1/2" or larger hardened steel all thread, a rented bushing install kit from the local auto parts store, copper anti-seize or similar lube and a WHOLE lot of elbow grease and beer. The subframe does not require complete removal. You do have to disconnect those brake lines I mentioned to give you the last nth of clearance and tilt the subrame with jacks or jack stand in order to access the corner you're working on. I recommend the tool from HPA because it was specifically designed for this task and if I had to do it again I would definitely utilize it. I was not aware of the HPA tool at the time that I did this mod. Plan on at least 2 days to allow for rest breaks because your going to need to take them frequently in order to prevent fatigue.

I have nothing but pro's for this mod. It completely transforms how the car behaves in pretty much every aspect of driving. There is a very slight addition of noise into the cabin during low rpm, high load acceleration but that pales in comparison to the benefits.