Rear Subframe bushings

[dimiras]

Im In the process of changing the bushes in my z3 to improve handling, now I have to choose which bushes should I fit in the rear subframe (Rear Beam).
I found poly bushes from strongflex in 2 Hardnesses 80sha or 90sha.
Which one do you guys recommend? Is strongflex a good brand?

 

[gookah]

I used strongflex 80s
absolutely fine.

 

[Delk]

Besides the raised subframe bushes I have used Strongflex and have had no issues.

 

[dimiras]

Did you noticed much difference from the OEM rubber?

 

[Delk]

Maybe a slight bit more road noise from the vibration but nothing major.

The car is lowered and I did alot to fix the camber and it drives much better now.

 

[Grumps]

When @Lee changed mine he suggested oem rubber bushes as I don't drive particularly hard and they are fine for my style of driving.

 

[dimiras]

Maybe a slight bit more road noise from the vibration but nothing major.

The car is lowered and I did alot to fix the camber and it drives much better now.

My car is lowered to what did you do to fix the camber?

 

[Delk]

I was lucky and picked up a full subframe and arms that I could overhaul and install in the car. This way I kept my original as is if I need it later.

Revshift 12mm raised subframe bushings and Strongflex red diff and swing arm bushings. I welded adjuster plates into the subframe so I could make all the final adjustments. I managed to correct the camber from between 3.5 to 4 degrees back to 1.5. The outside edge is now on the ground unlike before and I shouldn't wear the insides near as much. Thought about going to even 1 degree as I have very stiff sidewalls on 18 inch wheels so there isn't much flex but I left it as is. Toe in has been corrected and the car is much more settled on lumpy Norfolk roads.

I also narrowed the rear by installing Z4 hubs and E46 brake rotors. With the corrected camber I was going to have interference issues with the wheel arches since my rears are 265/35/18's and slightly wider then standard. With this set up I can now look at going even wider but I will wear these out first.

I drilled and installed grease fittings into the arms so I could lubricate the bushings in the future but this was a slight failure. The only place to install the fittings was on the forward top side of the bushings. With the raised subframe the inboard fittings were to close to the fuel tank for my liking and I removed them. With standard subframe bushings this wouldn't have been an issue.

The only thing I would do different next time would be the adjustment plates I used. I installed the toothed plates where you loosen the bolt and move the plates to make adjustments. These are secure and wont move in the future they were a pain to adjust in the car. Next time I would fit the eccentric bolts that move as you turn them. I think this would be far easier to adjust and after spot welded in place so they couldn't move by accident over time.

 

[dimiras]

I found out in some e30 forums that some people would flip the stock bushes and fit the appropriate spacers to the diff to raise the subframe and fix some of the camber in lowered cars. But for what I can see you cant do that with strongflex bushes because they seem to have the same height for both the bottom and top of the subframe. Do you guys know anything about this solution?

 

[Faheem]

Hi, not answering the question you've just asked but thought I'd share my opinion of the polyurethane bushes - I replaced all my rear subframe bushes with polyurethane bushes. Some were strongflex - for the rear beam and trailing arms. I went with powerflex for the diff bushing and rear ARB bush.

I've also replaced all the shocks and springs with bilstein shocks and eibach 30mm lowering springs.

Front control arms were changed along with the ARB bushes and droplinks themselves.

After doing all that the car does handle like new but I would say that the lowering springs combined with the polyurethane bushes does make it a very harsh ride. Almost to the point where it feels like a track car. You feel every bump in the road and hear every rattle in the car. Mine is fine as a weekend car but I can see that I would hate it for the daily commute as the potholes here would cripple not only my spine but also the car! If I were to do this again I would probably opt for OEM rubber bushings as I don't track my zed and it would definitely restore some of the ride quality.

 

[Steve Medlock]

I polybushed everything except the sub-frame bushes where I used OEM. New OEM bushes will definitely improve handling and may well give a nicer ride over poly.

 

[dimiras]

Besides the raised subframe bushes I have used Strongflex and have had no issues.

Do you have any pictures of the raised subgrame bushes?

 

[Andybpowell]

Hi, not answering the question you've just asked but thought I'd share my opinion of the polyurethane bushes - I replaced all my rear subframe bushes with polyurethane bushes. Some were strongflex - for the rear beam and trailing arms. I went with powerflex for the diff bushing and rear ARB bush.

I've also replaced all the shocks and springs with bilstein shocks and eibach 30mm lowering springs.

Front control arms were changed along with the ARB bushes and droplinks themselves.

After doing all that the car does handle like new but I would say that the lowering springs combined with the polyurethane bushes does make it a very harsh ride. Almost to the point where it feels like a track car. You feel every bump in the road and hear every rattle in the car. Mine is fine as a weekend car but I can see that I would hate it for the daily commute as the potholes here would cripple not only my spine but also the car! If I were to do this again I would probably opt for OEM rubber bushings as I don't track my zed and it would definitely restore some of the ride quality.

The other thing don't seem to take into account when replacing standard bushes and shocks/springs is that they are fitted with flexible bushes for several reasons including reducing both shock and vibration to vehicle components as well as the squidgy meat bag driving and those components tend to wear and fail sooner because of it I'm not saying don't do it but remember it comes with a cost

 

[Delk]

Do you have any pictures of the raised subgrame bushes?

No but its not uncommon and you should find some online.
The bush is just offset a bit to raise the suffrage and help with the camber.