Consensus on suspension bushes

[Weston Matt]

Hi

I’m just about to start replacing my bushes etc and wanted to know the general consensus on makes.

I could go down the power flex route but that will prove expensive, so I was looking at other options and was looking at Febi, Meyle Lemforder etc.

I have already replaced my springs and shocks

Thanks

Matt

 

[GuidoK]

I could go down the power flex route but that will prove expensive,

If you're going to do the work yourself, powerflex may be more expensive, but if you pay someone: fitting a powerflex bushing is usually way faster.

Also, for a lot of places in the suspension setup you can use strongflex bushings.
They are far cheaper and the polyurethane is the same quality.
For some spots I do advice powerflex, as on some spots they have a different design. For instance on the front lower control arm bushings.

Which bushings are you going to replace?
You already have all the right tools?

 

[Weston Matt]

Thanks for the reply

I’m looking at doing the work myself, i will have a look at the strongflex. What areas would you advise Powerflex? Looking at what you’ve done to your car it looks like you know your stuff!!
Haven’t got any specialist tools - I’ll see if I can hire or buy or get made by a friend

 

[Thermaltake]

Unless your planning on turning your car into a track car I would avoid poly bushes, It will make make the ride very hard and unforgiving for daily driving.

I done the major front and rear bushes last year. From all the reading around I did at the time. Meyle HD are the go to for everything bar the rear strut top mounts. I read about the clunking with the meyle HD ones but bought them anyway because they were £10 cheaper. And sure enough they made a horrible noise. Go for lemforder rear strut top mounts.

The only poly bush I would use is the rear trailing arm bush, I used powerflex one. they are about £50 more than the OEM rubber bush but you will save that £50 from the swear jar if you try and fit the OEM bushes yourself. The poly bush is a two piece which pushes in easily, The OEM is a rubber bush in a metal sleeve. As the trailing arm bush is a more a rotational force rather than damping it isnt too bad in terms of the ride. Use all the included lube and some more and you wont get any of the famous squeaking.

I used meyle HD for the front lower arms and lolipop bushes. Front droplinks, ARB bushes. Inner and outer track rods, Front strut top mounts. Powerflex for rear trailing arm bush and lemforder for rear strut top mounts. Had no issues with any of them and car feels much solid and sharper.

 

[Thrustyjust]

Horses for courses. I changed my lollipops and front arb's for 'road' Powerflex bushes and found them fantastic. I see no reason for fitting rubber there now or converting back. They are easy enough to fit in the cast lollipop , when you have managed ( 1/2hr of effort) to get the old ones out as dont have a hydraulic press and neighbour who does was away. Its made the car just as comfortable and to be honest , you have 2 ball joints that are directly bolted to the chassis rail and you are more than likely to get resonance through those than the 'road' poly bush. Yes, you can go black race ones and I am sure the durometer of those will increase noise. But as a modification to standard, I can say as have done the change, found them to make the car a little less wallowy and track well. Downsides maybe they could need greasing every couple of years, but its 4 bolts and they slip apart and can be done while on an oil change and be done by the time the oil stops coming out.

 

[Weston Matt]

Thanks guys. Food for thought.

As the car isn’t my daily i might do a bit of both. I’m thinking of getting H&R arbs so they come with poly bushes so that’s 4 sorted

 

[GuidoK]

Thanks for the reply

I’m looking at doing the work myself, i will have a look at the strongflex. What areas would you advise Powerflex?

Powerflex definately on the front control arm bushings. the strongflex ones have a design flaw.
Maybe the strongflex eccentric ones are good (similar design to powerflex I think). But those are usually only used on the z4m (it is a z4m replacelent)
I think the rest is OK regarding strongflex suspension bushings. (motormounts may be different, they only have a shore80a mount, which is really stiff for a motor mount)

As for stifness, for the front control arms I'd go for the powerflex purple ones.
The rear trailing arm front bushing should be shore90a/95a (so powerflex black or strongflex yellow)
The outer lower rear trailing arm bushing, you can replace that with a balljoint (33326775551). The same balljoint that is fitted on the upper outer point.
That is the same config as the z4m has. Use the lemförder ones (lemförder=OEM)

As for stiffness on the rear axle: I have shore90A.
That's a little stiffer than OEM but not as stiff as... say... fitting coilovers.
I don't know if fitting shore80a in the rear trailing arms is a good idea. Powerflex only has those bushings in shore95a (black), and not in their shore80a (purple) compound. Maybe they know something that makes them decide not to make purple ones.

As for diffbushings and subframe bushings: I have shore80a. With stiffer bushings you risk diff whine, and I decided on shore80a for subframe bushings because that dampens peak forces on the car monocoque. I don't want to risk getting torn subframe beams etc in the monocoque.

I don't have a lot of personal hands on experience with a lot of bushings as they are made now.
I polybushed my car about 9 years ago and quite a few bushings have had a design change (some small, some big). Back then also not everything was available from all brands so I have a mix of powerflex and strongflex. Back then some bushings were only carried by the one brand or the other. I even had to modify a certain bushing on my lathe as fitment on 1 particular bushing was poor (luckily they changed that design).
After 9 years, over 30k miles (hard driven miles with 380bhp) I haven't had a single bushing failure.
I had 1 failure, but that was from another brand, that was first on the market with a specific bushing. They had thought something out that clearly didn't work, at least not with the power of my engine :roll: .
Now that has been replaced by a powerflex one.

Nice thing about PU bushes is that they keep that "new car feeling" as PU doesnt age and get weak like normal rubber bushings do.

Haven’t got any specialist tools - I’ll see if I can hire or buy or get made by a friend

I can only advice this as a very necessary toolset:
https://www.ebay.co.uk/itm/284354587584

for the rest you'll need in some instances to make ends meet with some large sockets and rings where the cups in that set are too bulky.
(the top outer balljoint in the rear trailing arm can be a bit difficult).
Also to get the bushings out of the subframe you might need to heat it up a bit with a burner (not burning them out, just soften them) as extraction cups are difficult to place on the subframe.

When you're doing the complete rear axle it's pretty much necessary to drop the rear axle, so having a lift and a transmission jack is pretty much necessary. (so you have to drop the exhaust too).
Dropping the rear axle ideally is a 2 man job (don't forget to disconnect the handbrake :wink: )

When I did my rear axle, once I dropped the rear axle, all bushings were extracted in about 3 hours with the toolkit above. so less than 15min per bushing.
Of course you can buy the specific BMW tool per bushing, but you'll probably be spending £500 or more on specific extractor tools doing that. (per bushing a specific extractor tool usually costs £30-80, and there are 9 different bushings in the rear axle alone...)

I also did a complete overhaul of the rear axle (beadblasting, painting etc). That takes waaay more time :lol:

 

[Weston Matt]

Thanks for the detailed reply GuidoK very useful.

Do you find your car a harsher ride? I’m not turning into a track car but what it handling right

Thanks again

 

[GuidoK]

Do you find your car a harsher ride?

I think my car is currently quite a harsh ride. But the main component to tribute to that hars ride are my KW V3 coilovers.
So I have full polybushings, stiffer motormounts, coilovers, and stiffer arb's.
It's difficult to estimate how much exactly every component tributes as these upgrades were installed over a period of time, sometimes interweved (so partly polybushed->arb's->coilovers->rest polybushed for example).
but the coilovers make the car the stiffest.
Just polybushing it is perfectly acceptable imho.
But usually every tuning part adds to more harshness. It also adds to better roadholding. Those two go hand in hand.

 

[Thrustyjust]

Mine is a standard road weekend car. Other than fitting Eibach springs, the above poly bushes and normal tyres. Its actually pretty comfortable for what it is. Coming from my homebuilt Westfield with an S2000 engine , so same power but half the weight, I know this Zed is never going to be comparable with agility, steering feel and response. But having bought the car with the run flats removed was a good start. Fitting the Eibachs , with height raisers , gave me more plush progressive sprung ride with standard msport ride height. The geo check showed the tired lollipops and was advised by the guy who did the checks to go powerflex polybush as the better option. Getting the suspension dialled in again ( it had moved between bush changes) and replacing a corroded front ARB with a standard replacement and powerflex road ARB bushes with Meyle HD drop links, the car feels composed to the degree I hoped, no clunks, floor vibrations or any other form of negative issues other than bank balance changes

 

[Sludgepump]

Do you find your car a harsher ride?

I think my car is currently quite a harsh ride. But the main component to tribute to that hars ride are my KW V3 coilovers.
So I have full polybushings, stiffer motormounts, coilovers, and stiffer arb's.
It's difficult to estimate how much exactly every component tributes as these upgrades were installed over a period of time, sometimes interweved (so partly polybushed->arb's->coilovers->rest polybushed for example).
but the coilovers make the car the stiffest.
Just polybushing it is perfectly acceptable imho.
But usually every tuning part adds to more harshness. It also adds to better roadholding. Those two go hand in hand.

All these changes take resilience out of the suspension. Fine if you're on good tarmac but there's not much of that around these days. On uneven roads aren't you going to get more cracked wheels and broken coil springs? Horses for courses I guess but there must be a reason why the manufacturers fit rubber bushes.

 

[AndyBeech]

Do you find your car a harsher ride?

I think my car is currently quite a harsh ride. But the main component to tribute to that hars ride are my KW V3 coilovers.
So I have full polybushings, stiffer motormounts, coilovers, and stiffer arb's.
It's difficult to estimate how much exactly every component tributes as these upgrades were installed over a period of time, sometimes interweved (so partly polybushed->arb's->coilovers->rest polybushed for example).
but the coilovers make the car the stiffest.
Just polybushing it is perfectly acceptable imho.
But usually every tuning part adds to more harshness. It also adds to better roadholding. Those two go hand in hand.

All these changes take resilience out of the suspension. Fine if you're on good tarmac but there's not much of that around these days. On uneven roads aren't you going to get more cracked wheels and broken coil springs? Horses for courses I guess but there must be a reason why the manufacturers fit rubber bushes.

Yes cost and for comfort of the average car buyer :lol:

 

[GuidoK]

On uneven roads aren't you going to get more cracked wheels and broken coil springs?

No.
Apparently not.
And my front poly bushings have been longer in the car than the factory ones which were shot when I replaced them.
The powerflex bushings... they are (and feel) still like new.

So if any, certain parts are clearly better than the factory fitted counterparts, although that is not always the goal of tuning parts. Ususally the main goal is uprated performance.
Although I know a person that has done almost 200k miles with KW shocks until one failed (not on a z4 but a S2000). That is a very good record for any shock, OEM or performance oriented.