Z4m Coupe Anti Roll Bar Upgrade

[InterlagosMC]

Im looking to upgrade the anti roll bar setup on my z4m coupe and wondered what my option were. I like the look of the H&R e46 m3 kit but it doesn’t list as compatible with the z4.

Has anyone had experience fitting these and were any modifications required.

Thanks

 

[Jembo]

Morning

Regret unable to answer your question

However, interested to learn why you feel it’s necessary to upgrade this, as there’s other parts I’d normally expect u start with way before this

Cheers

 

[InterlagosMC]

My car has bilstein b12 kit at the moment with wheels that anre flush with the arch and it already has poly bushes on front and rear anti roll bars but just want a tighter feel on the back end more than anything. The front is pretty good already

 

[plenty]

If you still have the original rear springs you could experiment by fitting them as they are stiffer than the Eibach springs you have on now. They are also slightly taller meaning your rear ride height will raise slightly, but that may not be a bad thing as it will give your car positive rake which has an effect equivalent to stiffening rear spring rate.

 

[Jembo]

My car has bilstein b12 kit at the moment with wheels that anre flush with the arch and it already has poly bushes on front and rear anti roll bars but just want a tighter feel on the back end more than anything. The front is pretty good already

I found the B12 front springs too harsh for our pants UK roads with the B12 kit, so reverted back to OEM springs but the shocks & softer Eibach rears made huge difference

For the rear, suggest
1. RTAB’s & RTAL’s (Rear Trailing Arm bushes & Limiters) make a huge difference - I did both with Rogue Engineering
2. Then there’s the 3 rear diff bushes… if that baby’s squirming about it’ll never let the rear settle
3. Getting M track mode coded in
4. Rear top mounts tend to go sloppy so another area
5. A e46 CSL geo setup, though u may need front camber plates to get 100% settings

Suggest u look on forum for these first as will yield (from my experience & others) the best results

 

[InterlagosMC]

Thanks for the info, I will have a look at all of these options, Im planning lots of maintenance and upgrades in the coming year and want to get the handling spot on.

 

[plenty]

Just to be clear, I wouldn't actually recommend what I'm describing above. Jembo's advice is very sensible. Z4M handling benefits from a softer rear than OEM.

Adding rear spring rate, whether via OEM springs or a larger bar, is a backward step. I'm just mentioning swapping springs as a way to achieve a similar effect to a larger bar, that's easy to experiment with and see for yourself.

 

[peteslag]

I upgraded the arb's on my old z4 3.0. It massively reduced understeer but didn't seem to do much for the rear of the car. More lively perhaps.

 

[Ed Doe]

I upgraded the arb's on my old z4 3.0. It massively reduced understeer but didn't seem to do much for the rear of the car. More lively perhaps.

Precisely what arb tuning is about - you stiffen the axle you want to take grip away from, or soften the axle you want more grip from.

 

[mmm-five]

I put the e46 M3 28mm front and 21mm rear Eibach ARB kit on mine (kit no. E40-20-001-01-11) - no longer listed on www.eibachshop.co.uk though.

This was in combination of poly-bushing, Bilstein B16, and Porsche brake upgrades (and 12mm spacers).

 

[BMWZ4MC]

I’ve fitted H&R ARBs to mine, but that’s in combination with KW Clubsports and camber/castor plates,
RTAB limiters,
Rogue Engineering rear shock mounts,
an OEM strut brace / strut tower reinforcement plates and
Vibratech competition engine mounts.
I had to change the drop links to get the front ARB to fit with the KWs which, in turn, need spacers with some wheels (including the OEM wheels).

The result is an extremely stiff car which handles amazingly well on the smooth tarmac of a track but skitters around on broken roads even with the dampers backed off to their softer settings.

 

[Ed Doe]

I’ve fitted H&R ARBs to mine, but that’s in combination with KW Clubsports and camber/castor plates,
RTAB limiters,
Rogue Engineering rear shock mounts,
an OEM strut brace / strut tower reinforcement plates and
Vibratech competition engine mounts.
I had to change the drop links to get the front ARB to fit with the KWs which, in turn, need spacers with some wheels (including the OEM wheels).

The result is an extremely stiff car which handles amazingly well on the smooth tarmac of a track but skitters around on broken roads even with the dampers backed off to their softer settings.

That could be written about my car :lol:

 

[BMWZ4MC]

I’ve fitted H&R ARBs to mine, but that’s in combination with KW Clubsports and camber/castor plates,
RTAB limiters,
Rogue Engineering rear shock mounts,
an OEM strut brace / strut tower reinforcement plates and
Vibratech competition engine mounts.
I had to change the drop links to get the front ARB to fit with the KWs which, in turn, need spacers with some wheels (including the OEM wheels).

The result is an extremely stiff car which handles amazingly well on the smooth tarmac of a track but skitters around on broken roads even with the dampers backed off to their softer settings.

That could be written about my car :lol:

Intact vertebrae are overrated :lol: