E30 & Z3 M Compatibility

[Self Made]

Got an E30 overhaul brewing and Chris Foose is no where in sight.. so I really need someone else with all the answers to chime in.

Z3 M differentials bolt into the E30, just need to use E30 differential flanges for the halfshafts to work, right?

Or I could use Z3 M differential, flanges, and halfshafts. Are these axles really 'beefier'?

Then I would install the Z3 M trailing arms too. Yes I know they're 20mm wider.

Will I have to go 5 lug at this point or can I keep the 4 lugs with the Z3 M trailing arms?

TIA
Matt

[MR 325]

The Z3M diff fits with the E30 axle flanges, correct. The Z3M axles ARE beefier but won't fit in the E30 hub.

If you install Z3M trailing arms you will be running 5 lug.

[Eric]

Why not just install the entire Z3M rear subframe?

[Self Made]

The Z3M diff fits with the E30 axle flanges, correct. The Z3M axles ARE beefier but won't fit in the E30 hub.

If you install Z3M trailing arms you will be running 5 lug.

Aww they won't fit? Dang.. wierd because I thought you could just put z3 hubs on e30 axles.

[Self Made]

Why not just install the entire Z3M rear subframe?

I think that would require some modifications, I think the Z3 subframes a couple cm bigger.

[Farbin Kaiber]

Exact same size, but the trailing arms do make the final ET different from e30 parts.

[Self Made]

Exact same size, but the trailing arms do make the final ET different from e30 parts.

Thanks for the response. I know the ET will be different, that's ok. I just don't want to worry about breaking axleshafts if I ever dump the clutch by accident

So, to clarify, the 4 lug hubs will fit on Z3 M components?

[MR 325]

No. The 4 lug hubs will not fit. Z3M parts are totally different than non-M.

You should swap the complete rear assembly for the Z3M unit.

[Self Made]

No. The 4 lug hubs will not fit. Z3M parts are totally different than non-M.

You should swap the complete rear assembly for the Z3M unit.

That blows. Thanks for the info

[Self Made]

I've got one more question but I don't want to start a whole new thread. Does anyone know offhand if the non-M 6 cylinder Z3 axles can handle more torque than E30 axles?

I know the trailing arms are beefier with the extra brace. BTW they look just like the Z3 M trailing arms but have different part numbers