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

[dcaron9999]

Originally Posted by Neovison

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)

You are going to hate the fealing of runflats and solid bushings. If will be like riding on steel rims without the tires... ;-) Time to set some money aside for some good NON-RUNFLAT Exterme Performance (595RSR, RE-11, ZII-SS, AD08R, RS3-V2) , or Maximum Perfomance (S04, PSP) tires, as they are a very large part of the handling equation on a 135i ...

[rpsco]

Originally Posted by 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

Except the subframe mounting points in those cars are likely reinforced to handle it.

[BEAR-AvHistory]

Originally Posted by 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

IIRC they all run on get-flats.

[Neovison]

Originally Posted by rpsco

Except the subframe mounting points in those cars are likely reinforced to handle it.

Per Turner today, the E82 has nothing in common with the E36 or E46. I was wondering if I was endangering my chassis/rear sub frame with solids and asked if I need to reinforce the area before the install… They said absolutely! (only if you are North of 600 HP, otherwise you are completely fine)

[Neovison]

Originally Posted by dcaron9999

You are going to hate the fealing of runflats and solid bushings. If will be like riding on steel rims without the tires... ;-) Time to set some money aside for some good NON-RUNFLAT Exterme Performance (595RSR, RE-11, ZII-SS, AD08R, RS3-V2) , or Maximum Perfomance (S04, PSP) tires, as they are a very large part of the handling equation on a 135i ...

Thanks... I will... Given all the warnings above I actually received the Turner RSFB today, then drove to the post office and shipped them back. They spent one day flying to California, and now they're on a truck back to Amherst, Massachusetts (better vacation than I had)... I have the M1/M3 RSFB's going in on Monday... I couldn't really get to a solid answer on some of my questions. I think I did answer a few. TRUE - no chassis/rear subframe damage running these (on E82). TRUE - NVH is very minimal. TRUE - Virtually no maintenance. What I couldn't determine is the issue with the additional cycling the BMW PS suspension has to do and will that ultimately mess up the other rubber bushings everywhere else (since I was NOT changing the diff bushings...etc). Also, "harsh" ride is as subjective as it gets and no one can fully articulate bad/good/hard/soft via the internet... Just too many variables... The statement ... (the solid bushings)will be like riding on steel rims without the tires" is scary... I hope my issues are resolved with M3 RSFB/BMW PS... I'm certainly not a hardcore track type and value preservation over speed.. (keep the warranty intact too)

[MightyMouseTech]

I just put the M versions in. Can not believe how much better the car feels!!!!

You will be happy.

[NorthernDancer]

Mighty Mouse Tech - who put them in for you?

[MightyMouseTech]

Originally Posted by NorthernDancer

Mighty Mouse Tech - who put them in for you?

I did them myself.

[methodz]

Originally Posted by MightyMouseTech

I did them myself.

Did you rent the tool from hpashop?

[BMW135pls]

Got a question on the topic of bushing modification. I plan to upgrade my RSFBs to M3 models when the summer rolls around, but my question is about the front suspension bushings, and that's this: everyone talks about upgrading their rear bushings, but no one has mentioned front bushings. These cars have 50/50 weight balance, which is a great thing, but when you make the rear bushings stiffer than the front bushings, won't that affect the way the car pitches and rolls and upset that 50/50 balance? Or is it a situation where the front bushings are A-OK 100% and don't really need any modification to begin with?

[Solo_M_Tech]

Im pretty sure the front subframe is bolted directly to the chassis without bushings.

[dcaron9999]

Originally Posted by BMW135pls

Got a question on the topic of bushing modification. I plan to upgrade my RSFBs to M3 models when the summer rolls around, but my question is about the front suspension bushings, and that's this: everyone talks about upgrading their rear bushings, but no one has mentioned front bushings. These cars have 50/50 weight balance, which is a great thing, but when you make the rear bushings stiffer than the front bushings, won't that affect the way the car pitches and rolls and upset that 50/50 balance? Or is it a situation where the front bushings are A-OK 100% and don't really need any modification to begin with?

You can move the entire rear subframe with a long screwdriver stuck between it and the chassis. That's how soft the stock rear subframe bushings. BMW designed the bushings specifically for RunFlat tires, which have very stiff sidewalls.

The minute I replaced the RunFlats with sticker Extreme Performance Tires (RE-11 at the time), I noticed the exagerated rear end sway when taking curves. I first did camber plates and M3 front control arms (come with larger/stiffer bushings), and eventually DIY'ed the M3 rear subframe bushings. Both of these modifications made a large impact to the handling. The rear bushings made the largest difference, even on stock dampers + springs.


Notice all the openings in the stock bushing, versus a solid M3 bushing.

Pic of stock bushings ...


Pic of M3 bushings ...

[cpt97m3]

Originally Posted by HooningB2G

Im pretty sure the front subframe is bolted directly to the chassis without bushings.

This is correct, the front subframe does bolt to the chassis without any bushings. But many of us have upgraded to the M3 front control arms in addition to the M3 rear subframe bushings, and that will help the performance also. One of the M3 arms goes with a stiffer rubber bushing, and the other one has a solid bearing instead of the OE rubber bushing, plus it's a bit longer for extra camber.

[methodz]

For all of you DIY'ers of this mod out there, are you renting the bushing removal tool from somewhere or are you making some homemade bushing tool? I only ask because I called hpashop but don't feel like going on the waiting list. I've seen a few tools on YouTube but they've been for other cars and I'd kind of like to know what you guys have actually used to remove them.

Thanks!

[MightyMouseTech]

Originally Posted by methodz

Did you rent the tool from hpashop?

No, I just cobbled together some bushing press tools we had lying around the shop.

Would have been much faster with the proper tool.

I was in a unique situation. Our car got hit in the right rear corner, so it was in my works body shop. Our dealership group body shop is the shop for Honda, Acura, MB and BMW. The Acura techs do all the mechanical work for them. So, I was the one doing the insurance repair work to the suspension.

The right rear suspension had to be replaced, so instead of using the stocks parts, I installed the M3 arms and did the M3 bushings at the same time. Had to lower the subframe anyways.

Took me about 4 hours or so to do them. The hard part is getting the old bushings out. Putting in the new ones was much easier.

[dcaron9999]

Originally Posted by methodz

For all of you DIY'ers of this mod out there, are you renting the bushing removal tool from somewhere or are you making some homemade bushing tool? I only ask because I called hpashop but don't feel like going on the waiting list. I've seen a few tools on YouTube but they've been for other cars and I'd kind of like to know what you guys have actually used to remove them.

Thanks!

I did not rent the tool, but in hind sight should have done so. I decided to tackle the rear subframe bushing replacement as a DIY. I did not have the special bushing puller tool to do this, but I manage to salvage parts at the local hardware store, and build a mock up tool.

It was a P-I-T-A puliing the old bushings out. I broke and stripped countless number of washers bolts and threaded rods. Thank god I was using an electric impact gun, because extreme forces are required to remove the old bushings out and insert the new.

Do you yourself a favor, and buy 5/8" threaded rods. Anything smaller (1/2") will strip or break with the tremendous force required to remove the bushings.

Also keep lubricating your threaded rods with spray lube. Ditto for the four subframe sleeves, and bushings. Heating the sleeves with a torch did not help much.

Assuming you are not remoiving the subframe from the car, I recommend you loosen up the four main bushing bolts, to help you maneuver the subframe at the rear center point with one jack, and raise and lower one of the four corners you are working on with the other jack. You will need two quality jacks, as you will have to continuously re-adjust to gain enough space between frame of car, and subframe.

Also the rear brake lines need to be disconnected. Get yourself a bottle or two of your favorite brake fluid + pressure bleeder before starting, as you will want to bleed your lines after opening the brake lines.

Job took me about 12 hours, and three trips to the hardware store. What a bitch of a job. Now I understand why the shops wanted $800-$1000 for this.

Took the car to the track a little later with the new M3 bushing installed. Nice difference in the curves and especially through the esses, where weight is shifted rapidly from side to side. Floating and vague movement is greatly reduced. The car behaves much better over bumps when taking high speed turns.

On the street, it makes my 135i back end firmer, and more planted.

Overall, this is a great mod, and this DIY is worth the sweating and cursing.

[BMW135pls]

What is the perceived effect of putting M3 front control arms in? Less understeer into a turn? Is this something that someone who does not track their car would notice?

Also, could someone show me a trusted place to buy M3 RSFBs and maybe control arms if I decide?

[135TX]

http://www.ecstuning.com/BMW-E82-135...ion/M_Upgrade/

Best source for the parts.

I personally would say just from the street I can feel the difference in the front arms. Quicker turn in, less under steer, more neg camber, better tire wear.

I bought the TRW ones...

[BMW135pls]

Originally Posted by 135TX

http://www.ecstuning.com/BMW-E82-135...ion/M_Upgrade/

Best source for the parts.

I personally would say just from the street I can feel the difference in the front arms. Quicker turn in, less under steer, more neg camber, better tire wear.

I bought the TRW ones...

Thanks for the link.

Excuse me for being annoying, but this is the correct one for an N54 right? It looks different than the ones people have linked photos to in the thread.

http://www.ecstuning.com/BMW-E82-135...ade/ES1844489/

It's only $28 so I assume it's only one bushing and not a complete set? I need two of them?

[MightyMouseTech]

Originally Posted by BMW135pls

Thanks for the link.

Excuse me for being annoying, but this is the correct one for an N54 right? It looks different than the ones people have linked photos to in the thread.

http://www.ecstuning.com/BMW-E82-135...ade/ES1844489/

It's only $28 so I assume it's only one bushing and not a complete set? I need two of them?

That is the rear differential bushing, not the subframe.

You need 2 of these:

http://www.ecstuning.com/BMW-E82-135...frame/ES57295/

And 2 of these:

http://www.ecstuning.com/BMW-E82-135...frame/ES57296/

Originally Posted by BMW135pls

What is the perceived effect of putting M3 front control arms in? Less understeer into a turn? Is this something that someone who does not track their car would notice?

Also, could someone show me a trusted place to buy M3 RSFBs and maybe control arms if I decide?

The front suspension M3 arms have much stiffer bearings instead of rubber bushings, so you get faster steering response and less deflection when cornering hard, and the lower arm is a little longer than the stock version, so you get increased front negative camber for more grip from the front end.

The front arms is the first thing I did to my suspension, very highly recommended. Car feels much better with them in. And the increase in front camber means you can install wider front tires without rubbing.

Front suspension M3 arms:

http://www.ecstuning.com/BMW-E82-135...ade/ES2586480/

Then last on the list, if doing the rear subframe bushings, is to install the rear upper arms from an M3. Recommend doing these at the sme time as the RSFB's, as you will have the subframe lowered anyways, makes them much easier to change, and just do one alignment afterwards.

http://www.ecstuning.com/BMW-E82-135...ade/ES2622633/

[mr.fabulous]

Please stop, I promised myself when I bought my car that I'd leave it stock. Please stop.

[MightyMouseTech]