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Polybush Engine Mounts? Possible Subframe issues

2003 - 2009, roadster, coupe, facelift
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RichBergh
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Polybush Engine Mounts? Possible Subframe issues

Post by RichBergh » Mon Oct 16, 2017 8:38 pm

Hi guys,

I am in the middle of trying to make M3 front brakes fit on the Z .. Only doing this because i was given a set of brand new discs, pads and callipers from a mate of mine and soon, i will hopefully have a Big Brake Kit to fit from the same mate.
So far I've had to fit hubs and then wishbones off an E46 M3 as they are slightly different to the Z, one difference being that the ball joint is slightly thicker, so the standard arms don't fit.

So my problem lies, that on the left hand side, the wheel sits too far forward in the arch! However, the front right wheel is spot on.
Im thinking that i may have a slightly misshapen/bent subframe, causing the wishbone sit slightly wrong, so i have just bought an M3 subframe (which is the same across all E46/Z4)

I know i have to undo the engine mounts to take the subframe off, but my question is, has anyone replaced the engine mounts with polybushed versions? Do they create a lot more vibration, and cause the car to become more uncomfortable?

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markplant
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Polybush Engine Mounts? Possible Subframe issues

Post by markplant » Mon Oct 16, 2017 8:44 pm

3.0 Manual. Sterling Grey. Cream leather Electric an Heated. Professional Navigation/Sony tablet replacement. Storm Werks . an parts waiting to be fitted

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bradz
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Polybush Engine Mounts? Possible Subframe issues

Post by bradz » Mon Oct 16, 2017 8:50 pm

I had M3 calipers and discs on my 3.0

The discs bolt on to the normal hub, You just need to use an Si carrier for the M3 caliper, you need to grind about 1mm off the carrier to allow for the bigger 28mm disc.

I hope this helps...

The Z4M and M3 use a similar front sub frame, the sub frame on a 3.0 is not the same
Last edited by bradz on Mon Oct 16, 2017 8:52 pm, edited 1 time in total.
Z4M Coupe, E92 M3, E46 M3 Track car :driving:

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GuidoK
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Polybush Engine Mounts? Possible Subframe issues

Post by GuidoK » Mon Oct 16, 2017 8:50 pm

^^those are not polyurethane.
There are proper polyurethane engine mounts available in different designs but are generally stiffer than the VT ones.

If your subframe is bent, be sure to take a look at the chassis legs and especially the threads inside the bolts that hold the subframe.
The subframe is very strong, so if its bent, it got wacked pretty good. So this is a problem you need to take a very good look at.

And what do you mean that the standard arms dont fit? is the thread/rod from the balljoint thicker? (so that it doesnt fit properly in the hole of the hub)
Z4 3.0i | ESS TS2+ | Quaife ATB LSD | Brembo/BMW performance BBK front/rear | Schrick FI cams | Schmiedmann headers+cats | fully polybushed | Vibra-technics engine mounts | H&R anti rollbars | KW V3 coilovers | Sachs Race Engineering clutch

RichBergh
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Polybush Engine Mounts? Possible Subframe issues

Post by RichBergh » Mon Oct 16, 2017 8:55 pm

bradz wrote: Mon Oct 16, 2017 8:50 pm I had M3 calipers and discs on my 3.0

The discs bolt on to the normal hub, You just need to use an Si carrier for the M3 caliper, you need to grind about 1mm off the carrier to allow for the bigger 28mm disc.

I hope this helps...

The Z4M and M3 use a similar front sub frame, the sub frame on a 3.0 is not the same
Gutted! .. i thought the si ran the same brakes as the 3.0i brakes! .. absolute nightmare haha

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bradz
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Polybush Engine Mounts? Possible Subframe issues

Post by bradz » Mon Oct 16, 2017 8:56 pm

Front sub frame on a

3.0 is part no 31111096902
3.2 is part no 31117838589
Z4M Coupe, E92 M3, E46 M3 Track car :driving:

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bradz
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Polybush Engine Mounts? Possible Subframe issues

Post by bradz » Mon Oct 16, 2017 8:58 pm

RichBergh wrote: Mon Oct 16, 2017 8:55 pm
bradz wrote: Mon Oct 16, 2017 8:50 pm I had M3 calipers and discs on my 3.0

The discs bolt on to the normal hub, You just need to use an Si carrier for the M3 caliper, you need to grind about 1mm off the carrier to allow for the bigger 28mm disc.

I hope this helps...

The Z4M and M3 use a similar front sub frame, the sub frame on a 3.0 is not the same
Gutted! .. i thought the si ran the same brakes as the 3.0i brakes! .. absolute nightmare haha
The 3.0 uses 300mm
the 3.0si uses 325x25

the M3 uses 325x28 (semi floating)
Z4M Coupe, E92 M3, E46 M3 Track car :driving:

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