Did I just make a huge mistake... solid rear subframe bushings

[Neovison]

Hi,

Long time lurker, but this maybe helpful for some... I have 135i coupe, and after a huge amount of research I decided to buy new BMW Motorsport rear subframe bushing and install the BMW Performance suspension. I wanted the BMW MS bushings because I wanted wayyyyy tighter than stock and I thought I would go stiffer than the M3 bushings (they do get rave reviews though)... So the problem... I wanted solid aluminum bushings. I was very, very discouraged from this by the BMW Dealer and the tech guy (accomplished dude) who builds race cars. He said he had them (not on a E82 though) and said that the solid bushing will make for a SOLID rear subframe, therefore It will start breaking my BMW perfomance suspension parts. Just too much energy cycling through suspension. On the other hand, I hear that the solid mounts have very little NVH and handle dreamy and actually prevent stuff from breaking (and no maintenance, and new M3, M4, M5 have solid rearends). The BMW dealer couldn't get the BMW MS bushings, so order at Turner MS. Talked to tech and told him why I'm going BMW bushings over solids... He then told me that NO solid aluminum will not break suspension parts, is maintenance free, will drive dreamy, have lowish NVH and I'll love it. I flipped the order from BMW MS bushings for $850 to Turner solids bushings for $350. BMW will install but reluctantly. SO - did I screw up? should I have gone heavy rubber BMW MS bushings to preserve my car, or did I do good and buy Turner solid aluminum bushings to preserve my car? Can anyone answers this provative question? The one thing we all agree on is that the stock bushings are universally hated. Thanks in advance for your insight. I hope this string will help other with the same conflict... The turner solids and BMW PS go in on Monday. THX!

[methodz]

Well, I just installed the BMW PS suspension and have the M3 bushings ready to go in. But after riding the performance suspension for a few days that alone satisfied my woes in the cars handling. Stock absolutely sucked and had me thinking I bought the wrong car lol but now it's all good. Now I may put off installing the bushings because I'm actually pretty happy with my setup for my driving habits. Though it should be noted that I did install the M3 front control arms as well. I will do the rear subframe bushings because I bought them already but I'm in no rush. I would imagine a solid bushing would be HARSH! I don't know how serious you want to drive your car with track events and such but I have to think solid bushings for daily driving might be a bit of overkill. But, that's just my humble opinion.

If you haven't installed it just return it if you're having second thoughts.

[BLU135i]

PeteA here on the forum has the Turner solids installed on his car. I asked him about them and he said he had no noticeable increase with NVH. I'd do it, unless you live here on the right coast with these shitty roads. Give him a holler and inquire more.

[e36addict]

I have a buddy with an E92 M3 that's basically his track car.. It has all sorts of suspension goodies including solid aluminum rear mounts. The car feels fine on the street..very, very good in fact. The only downside I can see is that you hear a bit more diff whine.. which would annoy me on the highway but it's not really that loud. If I ever do my bushings again for some reason i'll probably go solid.

[dcaron9999]

Post #1 ! Welcome to the forum !!!

Someone on this forum mentioned that the new M3 and M4 run with solid RSFB's, so NVH must not be so bad with stiffer durometer AKG rubber or aluminium bushings. I DIY'ed M3 RSFB's on my 135i, and it made a huge difference in handling and rear end planted fealing. Cant help but wonder what solid's would have been like.

Probably would try them if I was you. The labor is somewhat involving though and mechanics will likely ask for 6-8 hours of labor.

What ratio of street and track driving do you have planned for your car?

What tires are you running with? (as you probably know, the soft stock RSFB's are designed for RunFlat tires)

See this thread about various options for subframew bushings - might reduce your anxiety level ...
http://www.1addicts.com/forums/showthread.php?t=1095127

[uberschnell]

It's seems kind of odd to me that you are mixing BMW PS suspension, which is a compromise between comfort and performance with solid RSFB, which is hardcore performance oriented. I could see it if you were dropping in serious performance mods like Ohlins with 400/800 springs, LSD, complete rear M3 suspension parts, etc.

It seems this level of hardcore, compared to say M3 RSFB, might be a waste if you don't plan on addressing the crap load of other short-comings the car's suspension still has.

I'm all for beefed up RSFB, but if anything, the solid RSFB will make the other weaknesses more noticeable.

[dcaron9999]

Originally Posted by uberschnell

It's seems kind of odd to me that you are mixing BMW PS suspension, which is a compromise between comfort and performance with solid RSFB, which is hardcore performance oriented. I could see it if you were dropping in serious performance mods like Ohlins with 400/800 springs, LSD, complete rear M3 suspension parts, etc.

It seems this level of hardcore, compared to say M3 RSFB, might be a waste if you don't plan on addressing the crap load of other short-comings the car's suspension still has.

I'm all for beefed up RSFB, but if anything, the solid RSFB will make the other weaknesses more noticeable.

You sir, make a very good point ... May become an unbalanced setup if the OP chooses Alu or solid rubber bushings to combine with stock dampers/springs or near stock "Performance Suspension" dampers/springs.

I guess it really depends on OP's eventual purpose for his car. Is he taking small steps towards an ultimate track car? Is he looking for an intermediate phase for a dual duty car? Is he looking for a mild mostly street use upgrade?

If its one of the last two options, than E92/M3 RFSB's will be adequate. Some even get away with inserts to save on parts and mostly labor costs. I myself have done M3 RFSB's and track my car heavily. Im quite happy with them.

[Zombie1]

The M3 bushings are amazing love the car can't say enough about them. I think you'll be alright with the solid ones, but like above metal Subframe bushing is hardcore compared with bmw PS. Let us know how it works out man.

[twinboost_MD]

yea i think solid is definitely overkill plus you can really throw out something else. thats a lott of energy going through there

[ilikebmxbikes]

i have solid rear subframe bushings. They dont really induce any additional noise or vibration. Diff bushings, motor mounts and transmission mounts all ad a lot more NVH.

[Dackelone]

I think your nuts. Your not driving on a race track! Why go with solid race parts? Your gonna regret it.

The ///M parts are really well made and last and have very little NVB impact on the way the car sounds to the occupants. But you WILL notice how much better the car steers and tracks into the turns and out of them.


Dackel's replacement of rear suspension OE bushings with M3 ones…
http://www.1addicts.com/forums/showt...frame+bushings

[PeteA]

I would do coils first + M3 SFB, then M control arms/sways, then I'd start playing with solid SFB's. If you plan on going hardcore, save urself the labor an go directly to aluminum. NVH trade off is definitely worth it.

I have them, but I also have Ohlins coils and a full M control arm setup. The step up from 135i -> M3 SFB - > Aluminium was all progressively better, but the NVH didn't increase too much at all.

The most NVH was induced by my hard riding RS3 Hancook tyres lol.

Pete

[CAVU]

I'm running the BMW Performance Suspension with Whiteline rear subframe bushing inserts. I could accept a bit harsher ride, but right now I have the right balance for my daily driving needs. Handling is more buttoned down for those spirited drives when I'm by myself, but my wife doesn't complain about a harsh ride when she's a passenger. Plus I have a small amount of drop. On the contrary, I'd say the ride with the PS springs and bushings is a bit better than it was with the M Sport suspension.

[chris82]

Yea, aluminum bushings are overkill. It's not like you have $3000 dampers in there, and it's not a dedicated track car. Even if it was, the M3 bushings are plenty, they really are. A former race tech who sets my car up, says the M3 bushings get the job done plenty good, no need for anything stiffer, this is from a guy who sets BMW race cars up for a living . . .

[Neovison]

Originally Posted by methodz

Well, I just installed the BMW PS suspension and have the M3 bushings ready to go in. But after riding the performance suspension for a few days that alone satisfied my woes in the cars handling. Stock absolutely sucked and had me thinking I bought the wrong car lol but now it's all good. Now I may put off installing the bushings because I'm actually pretty happy with my setup for my driving habits. Though it should be noted that I did install the M3 front control arms as well. I will do the rear subframe bushings because I bought them already but I'm in no rush. I would imagine a solid bushing would be HARSH! I don't know how serious you want to drive your car with track events and such but I have to think solid bushings for daily driving might be a bit of overkill. But, that's just my humble opinion.

If you haven't installed it just return it if you're having second thoughts.

Thanks for the insight Methodz... The big concerns were: will i break suspension stuff?(I don't think I will at this point). Do I need to reinforce the unibody? (I was told by a credible source that I'm good with the 135i). NVH? Looks like I'm fairly good there, but the X FACTOR is what will the ride really be like overall. "Harsh" is really subjective, and I'm not into anything remotely like the stock handling - In fact I was so turned off by the backend that I might have gone overkill with the solids? I'm coming off a 2009 Sti though, so fluffy ride is not what I want. I really wonder what I'm in for?

[Neovison]

thanks Blue135i.. I'll ask him... I'm on the left coast (streets just as bad)

[Neovison]

Originally Posted by e36addict

I have a buddy with an E92 M3 that's basically his track car.. It has all sorts of suspension goodies including solid aluminum rear mounts. The car feels fine on the street..very, very good in fact. The only downside I can see is that you hear a bit more diff whine.. which would annoy me on the highway but it's not really that loud. If I ever do my bushings again for some reason i'll probably go solid.

Thanks E36Addict... Your opinion has me less freaked out by the knee jerk switch to TMS solids...

[Neovison]

Originally Posted by dcaron9999

Post #1 ! Welcome to the forum !!!

Someone on this forum mentioned that the new M3 and M4 run with solid RSFB's, so NVH must not be so bad with stiffer durometer AKG rubber or aluminium bushings. I DIY'ed M3 RSFB's on my 135i, and it made a huge difference in handling and rear end planted fealing. Cant help but wonder what solid's would have been like.

Probably would try them if I was you. The labor is somewhat involving though and mechanics will likely ask for 6-8 hours of labor.

What ratio of street and track driving do you have planned for your car?

What tires are you running with? (as you probably know, the soft stock RSFB's are designed for RunFlat tires)

See this thread about various options for subframew bushings - might reduce your anxiety level ...
http://www.1addicts.com/forums/showthread.php?t=1095127

Thanks for the welcome.. I'll go with 25/75, but that maybe wishful. I disdain the current floaty feel and don't mind NVH. I'm on the stock tires. I know how bad they are, and the only thing that will solve that part of the suspension equation is new tires (already spent the rent $ on suspension, so tires next)

[Neovison]

Originally Posted by uberschnell

It's seems kind of odd to me that you are mixing BMW PS suspension, which is a compromise between comfort and performance with solid RSFB, which is hardcore performance oriented. I could see it if you were dropping in serious performance mods like Ohlins with 400/800 springs, LSD, complete rear M3 suspension parts, etc.

It seems this level of hardcore, compared to say M3 RSFB, might be a waste if you don't plan on addressing the crap load of other short-comings the car's suspension still has.

I'm all for beefed up RSFB, but if anything, the solid RSFB will make the other weaknesses more noticeable.

Valid point, but it was a balance talking to tons of people with varied experience and varied opinions. I did want to begin by attacking the the primary weakness in my eyes. NVH not really a problem for me. I was pretty disappointed with the suspension feel and when I pulled the rear frame back and forth with my left hand and a bar I couldn't believe it. Originally I was getting BWM PS with M3 RSFB, then decided BMW MS RSFB, then freaked out on the phone with Turner and flipped the order to solid aluminum(they are so pretty... and saved $450 too). Some folks have said that the solids with the BMW PS might be great (minus the RF tires) and low maintenance.

[Neovison]

Originally Posted by Dackelone

I think your nuts. Your not driving on a race track! Why go with solid race parts? Your gonna regret it.

The ///M parts are really well made and last and have very little NVB impact on the way the car sounds to the occupants. But you WILL notice how much better the car steers and tracks into the turns and out of them.


Dackel's replacement of rear suspension OE bushings with M3 ones…
http://www.1addicts.com/forums/showt...frame+bushings

Thanks for perspective.. I'll report back on the result.. Nothing's more subjective than asking about RSFB opinions. It's like posting a message "hey guys, what's the best motor oil?"... That usually starts wars... I decided on the M3 RSFB because of your install... Then I thought "what is better than firm", then I though "hard is better than firm", so off to purchase the BMW MS bushing over the M3 ones, then I thought, "what's better than hard... hmmm.. frozen rock solid is better than hard" I'm kind of an overkill type of guy anyway.

[BEAR-AvHistory]

As a general rule of thumb, pure race parts are never the best plan for a street car. IMHO most race cars travel the streets on trailers.

[PeteA]

M3, M5, M6...probably M2. All directly bolted subframe to chassis. I say go for it. At least you know it will never require maintenance