Any Z4 M coupe with polyurethane bushings all around?

[Rev2Liv]

Looking for E86 Z4M coupe or E46 M3 coupe owners who have replaced all suspension/subframe bushings with polyurethane or delrin solid upgrades.

I'm looking for reviews/observations from people that replaced all the bushings with polyurethane or solid and not just one or two spread out.

-rear subframe bushings
-differential mounts
-rear trailing arm bushings (RTAB)
-inner-upper rear control arm
-sway bar Front+rear
-Front control arm bushing (FCAB)

These combined with a quality coilover kit would transform the car, but with how much added NVH. I've driven friends E46 M3's and have always felt that the ride was quite compliant (even with 19" wheels) and in need of firming up.

Over a decade ago, I had an Acura RSX Type-S that I swapped out all the suspension bushings with hard compound polyurethane bushings. NVH was increased compared to stock, but definitely tolerable for everyday driving. I was mostly concerned with harshness but never got to play around with that since I didnt' want to mess around with different spring rates and such.

Handling became much sharper and responsive. Steering is where I found the most benefit. Turn-in response was much improved along with feedback.Before, quick transient maneuvers like changing lanes felt lazy with delayed reaction. With polyurethane, reflexes were much quicker.

The only drawback was the reduced ability to modulate anddampen transient undulations in road surface. At highway speeds, increased vibration was noticeable with all irregularites on the road felt. whereas before, small transient bumps in the road would be attenuated, now they were transmitted into the cabin felt at the steering wheel and seat.

I found it quite tolerable, however, my mom would get carsick at times and considered the ride too harsh for street use.

With the polyurethane bushings and new shocks in place, i'd be very curious to see how the Z4 M coupe stacks up to the Porsche Cayman S. Steering and shifting would become much more responsive and crisper. The Z4 M coupe already features the sharper steering rack from M3 CSL providing an excellent foundation. Had the M Division spent more time fine-tuning the suspension settings and calibration, this car could have been up there with the E30 M3 in the fun-to-drive department.

[inTgr8r]

I've done FCABs, RTABs, ARBs f&r
Very happy with the results, no noticable NVH difference.
Re crisper shifting....
Trany bushings, Vibratech motor mounts & AS SSK are the answers there.

They definitely tighten things up.
A couple of weeks ago was the first track day on them & the car has never been better

[BIMMERGUY91]

I second that on the transmission mounts and motor mounts.

One thing I noticed you said about comparing to the Cayman. Around a track the M Coupe is already directly comparable. In some ways it is better.

[Master Apex]

What brand/model did you end up using for :
-rear subframe bushings
-inner-upper rear control arm
-Front control arm bushing (FCAB)

[inTgr8r]

MY FCABs are Superflex from UK.
http://www.superflex.co.uk/proddetai...od=SF095-2558K
They were originally designed to provide different caster settings on the E46 M3, but work perfectly on our cars..

[racerbruce]

Originally Posted by inTgr8r

MY FCABs are Superflex from UK.
http://www.superflex.co.uk/proddetai...od=SF095-2558K
They were originally designed to provide different caster settings on the E46 M3, but work perfectly on our cars..

Great news!
The Superflex weblink for E46 will fit our Z4M? Did this help handling? Are they noisy? Presumably they fir the existing FCAB housing.

Thanks!
Racerbruce

[inTgr8r]

Originally Posted by racerbruce

Great news!
The Superflex weblink for E46 will fit our Z4M? Did this help handling? Are they noisy? Presumably they fir the existing FCAB housing.

Thanks!
Racerbruce

Not noisy at all and a nice improvement in the handling.
The car felt great on my last track day!

Installed pic

[AriuSen]

Originally Posted by inTgr8r

Not noisy at all and a nice improvement in the handling.
The car felt great on my last track day!

Installed pic

do you know if there is an option for delrin bushings?
Since my car is a track car, I dont mind going with delrin all around.

[inTgr8r]

Not that I'm aware of.
The issue is finding a bush with the offset centre.
Without the offset you lose caster.

[AriuSen]

Originally Posted by inTgr8r

Not that I'm aware of.
The issue is finding a bush with the offset centre.
Without the offset you lose caster.

yea i thought so....thank you

[GuidoK]

I've seen adjustable e46 lollypops with delrin inserts (or was it pillowball?) from some race supplier.
That's 100% firm and you can dial in the caster yourself.

Loads of delrin offset bushings for the e30, z3 etc for sale, but I suspect that they are 60mm (but you can always ask various suppliers)

[Shipkiller]

Originally Posted by inTgr8r

Not noisy at all and a nice improvement in the handling.
The car felt great on my last track day!

Installed pic

I thought you have the PowerFlex.
Those look like Whiteline FCAB's inserts, like what is installed on my car.

[inTgr8r]

Originally Posted by Shipkiller

I thought you have the PowerFlex.
Those look like Whiteline FCAB's inserts, like what is installed on my car.

They are the SuperFlex bush out of the UK

[AriuSen]

Originally Posted by inTgr8r

They are the SuperFlex bush out of the UK

Just bought it! Do I need alignment again after?