M3 Rear Subframe Bushings

[ASAP]

I apologize in advance but this is a random question...

From the M3 rsfb's, would the 2 fronts make a bigger difference or the rears?

[dcaron9999]

Good question.

I think they all contribute evenly, as they sit at the four corners of the subframe.
Why do you ask?

[ASAP]

Originally Posted by dcaron9999

Good question.

I think they all contribute evenly, as they sit at the four corners of the subframe.
Why do you ask?

Lol, let's just say during the 1st go around we were only able to get the rears in and left the stockers on the front... Now I am curious how much of the improvement that I am feeling. Will try the fronts in another week or two when we get a better tool.

[ASAP]

Maybe, I am crazy but I feel like the two fronts would be more important as they probably hold more weight and there would be mote chassis flex there.

[128Convertibleguy]

Any suspension member with bushings on both ends with a substantial difference in stiffness at the two ends, is obviously going to flex more at the weaker end. I think the benefits of just doing one side are pretty limited.

[DietTab]

All you need is a torch and a socket. Takes 2 minutes per corner to let the car's weight push the bushings out.

[dcaron9999]

I did the 4 RSF bushings as a DIY without the proper tool, and it was a bitch. Used heat, impact wrench, assortment of washers, threaded rods, nuts, and two hydraulic jacks. Brake lines also have to come off to allow sufficient subframe movement for the front bushings, IIRC ...

[brocklanders]

I went with the whiteline poly bushings, install was cake, it was harder to change the sway bar. I have no noise or vibration what so ever, there is no reason in my mind to use expensive softer bmw parts for this upgrade.

[TheSt|G]

Originally Posted by brocklanders

I went with the whiteline poly bushings, install was cake, it was harder to change the sway bar. I have no noise or vibration what so ever, there is no reason in my mind to use expensive softer bmw parts for this upgrade.

Says someone who does not have them installed.

[brocklanders]

Originally Posted by TheSt|G

Says someone who does not have them installed.

I have had them in the past.

[KD718]

Anyone have detailed pics or directions doing it with a torch and a socket?

[houtan]

A lot of good info and suggestions here http://www.1addicts.com/forums/showthread.php?t=802595. I just installed the two piece whiteline RSFB using information in that thread. However, I opted to rent the tool from hpautowerks to remove my bushings. Either way, you're going to need two jacks. Install was straightforward and the bushings came out easily with the tool but others have successfully used the weight of the car and applied heat to remove the bushings. Took me about 5 hours by myself taking my time to apply all the information in the thread and choose an install route. Couple of notes from my install are: I only disconnected the bottom nut on the rear shocks and nothing else suspension wise; I did not disconnect my exhaust, I disconnected my brake lines.

[ASAP]

Guys, the bushing job is not that easy. The rears arent too bad but the fronts go in from the top if you get the m3 ones. You need to lower the subframe enough to gain clearence and press it in. We had a professional bushing tool when doing this, even the regular bmw one wasn't too good. If you have the tool and have done it before it's simple but without the tool I can imagine this being a disaster. Also, to gain enough clearence, the rear brake lines need to be disconnected... so add a brake flush to your checklist.

[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.

[Solo_M_Tech]

I am getting the rsfb installed next month and I can't wait.

[chris82]

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.

Something doesn't sound right . . .

[Solo_M_Tech]

Agreed with above statement.

[FactorX81]

Originally Posted by chris82

Something doesn't sound right . . .

+1
I was going to do the bushing this summer but if it still flops around I'll skip it. I have kinda gotten used to it now, and still have fun at the track anyway.

[chris82]

Originally Posted by FactorX81

+1
I was going to do the bushing this summer but if it still flops around I'll skip it. I have kinda gotten used to it now, and still have fun at the track anyway.

I've been on these forums a while and everyone who does the bushings say they make a huge difference. You could always try the solid aluminum ones from turner. They're $300 and from what I read do no introduce much extra NVH

[fboutlaw]

Originally Posted by ASAP

I apologize in advance but this is a random question...

From the M3 rsfb's, would the 2 fronts make a bigger difference or the rears?

Finish the job.

You're probably getting ~50% the benefit, but you're going to destroy the new bushings since you have 2 supporting the movement of the car now. The stock ones are doing nothing other than being a placeholder. The new ones will prevent the car from moving much and the old ones won't provide much resistance at the small amounts of deflection.

[TS135i]

@ASAP
I also have RSFB along with rear upper/lower M3 control arms, I dialled the Koni's at front 1&1/4 turns, rear 1 turn - car feels right now.

[John_01]

If you feel the car is unstable due to the short wheelbase, you can use a front sway bar upgrade to make it settle down. Especially if you use non-staggered tires sizes and have increased the front camber.