Z4M (offset) front control arm bushings on E46 M3

[cornerbalanced]

While my front subframe is dropped, I figured its a good idea to swap out FCABs.

Has anyone pressed OE Z4M offset FCABs into their stock housings? Would this be reccomended? Ontop of being marginally stiffer than OE M3 FCABs, they're not liquid filled so they should last longer, and they are offset providing for more caster. I have found regular 330i people doing this swap, but have seen no M3 people do it so figured I'd make a thread so this matter can be searched upon in the future.

Looking to avoid poly/spherical FCABs. Even though I'm doing solid subframe, poly diff, sperhical RTABs, etc. etc. etc. It appears FCABs are best left OE/OE+ for street driving.

[Sharocks]

No I just hit up the dude that replaces the stock FCAB's on the forum.

Usually once every few years.

[Tbonem3]

No need if you have camber plates, but perhaps for a car with stock mounts.

[bigjae46]

The OEM M3 FCABs aren't filled with hydraulic fluid...nothing on the M3 is.

[Tbonem3]

I think just the engine mounts. I've seen them ooze grease.

[01SG]

The front z4 M suspension is based on the e36 m3. I do not think these would work out given that they need the proper control arm geometry to function. For example, using the offset bushings from the 95 m3 in the 96-99 models will not work. The control arm is different. It pushes the wheel too far forward. In order to run offset bushings on the later model e36, you need the control arms from the 1995. Z4 M control arms are not going on your e46, and so this is not a viable option.

[PetrolM3]

The front z4 M suspension is based on the e36 m3. I do not think these would work out given that they need the proper control arm geometry to function. For example, using the offset bushings from the 95 m3 in the 96-99 models will not work. The control arm is different. It pushes the wheel too far forward. In order to run offset bushings on the later model e36, you need the control arms from the 1995. Z4 M control arms are not going on your e46, and so this is not a viable option.

They seem to work on non-M cars which has relatively similar geometry to M3. Not saying they will work on the M3 but just saying…

[cornerbalanced]

The OEM M3 FCABs aren't filled with hydraulic fluid...nothing on the M3 is.

Just the engine mounts, but you’re right. I was reading info off the ZHP forums when they referred to the OE bushings as liquid filled—didn’t connect the dots that the M3 FCABs would be different.

[cornerbalanced]

The front z4 M suspension is based on the e36 m3. I do not think these would work out given that they need the proper control arm geometry to function. For example, using the offset bushings from the 95 m3 in the 96-99 models will not work. The control arm is different. It pushes the wheel too far forward. In order to run offset bushings on the later model e36, you need the control arms from the 1995. Z4 M control arms are not going on your e46, and so this is not a viable option.

This is what I was most curious about, and the primary reason why I posted this thread in the first place. Yes, in theory that makes a lot of sense. There are however a lot of non-M E46s (ZHPs, etc) running these without issue, which lead me to believe they may work.

Probably just going to go OE for simplicity’s sake.

[01SG]

Apparently the Z4 M uses ZHP control arms, at least according to the Bimmerworld description. That explains why they might work on that car. Regardless, the E46 M has a different design. They are not interchangeable. I would indeed stick with OE.

[thegenius46m]

I believe the ID of the Z4M bushing is different than the E46 M3 variant

[PetrolM3]

I believe the ID of the Z4M bushing is different than the E46 M3 variant

That’s not possible because both of them fit in the non-m lollipop..

[bigjae46]

I believe the ID of the Z4M bushing is different than the E46 M3 variant

Its been awhile but i think earlier model E46s were 60mm ID and then updated to 66mm. Could be E36 vs E46 thing as well.

Either way, a stock E46 M3 FCAB is your best non-spherical option. If you are looking for more negative camber then use a non-M Vorshlag camber plate. Otherwise just keep it stock because there aren't any other options that don't require more frequent maintenance and inspections...aka suitable for street use.

[terra]

Its been awhile but i think earlier model E46s were 60mm ID and then updated to 66mm. Could be E36 vs E46 thing as well.

Either way, a stock E46 M3 FCAB is your best non-spherical option. If you are looking for more negative camber then use a non-M Vorshlag camber plate. Otherwise just keep it stock because there aren't any other options that don't require more frequent maintenance and inspections...aka suitable for street use.

Non-M was increased to 66. E46 M3 stayed at 60

I think the actual hex hole that the control arm slots into is bigger on the e46 m3 too

I did run the Z4M bushings on my ZHP when I had one. It was a nice little upgrade there. But I don’t think the e46 M3 would necessarily benefit.

[the_fly]

Late post but figured I'd chime in since I've pressed about 200 FCABs of all kinds for folks...

The hex hole is the same. However, going to the Z4m units means that you would lose the reinforcement undertray that the 3rd mounting point on the e46m3 lollipop gets you. And as mentioned, they are different diameters (60 vs 66).

Agree that stock rubber FCABs are best for e46m3. Though I press poly units for the XI, poly is not recommended for e46m3. Plenty of folks have seen heat-related failures due to proximity to the exhaust headers.