Polybush help in North West

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Dva99999
Joined: Mon 28 Sep, 2015 20:58
Posts: 7

  Z3 roadster 2.8

Polybush help in North West

Post by Dva99999 » Sat 31 Oct, 2015 19:42

Hi all,
I've recently bought a Z3 2.8 manual which although fairly quick is a bit scary on motorways. The car feels like it's wallowing and doesn't shoot straight under acceleration. I've heard this may be the 'tramlining' effect from other posts and the way to stop that is to upgrade the bushes.

Can anyone point me in the right direction as to:

A) what bushes to get and
B) a reputable garage in the North West/Cheshire area to fit them.

Looking at the diagrams it's not something I could do myself and some of the descriptive wording on Mike Fishwicks post is beyond me.

Any help would be much appreciated.

Regards
D

maurice the martian
Joined: Tue 26 Jan, 2010 19:44
Posts: 1026

  Z4 roadster 3.0i
Location: mars

Re: Polybush help in North West

Post by maurice the martian » Sat 31 Oct, 2015 19:53

Hiya an welcome, dunno where you are, but Darren Woods , bredbury, nr Stockport is a well respected and trustworthy indi,
Does all my work and loads of other bmw owners,
The probs you describe could be tyre related also, I had this prob with mine Z4, changed the tyres and it was better, polibushed all the front and the rear , zed now drives like its on railtrack.
Moz

peter2b
Joined: Sat 01 Nov, 2014 18:47
Posts: 963

  Z3 roadster 2.2i
Location: cheshire

Re: Polybush help in North West

Post by peter2b » Sat 31 Oct, 2015 19:54

I tnink it might have some thing to do with the tyres do a search on this site might show some thing,I have a man shed with a twin arm car lift if you need it over a week end
peter2b

Del
Joined: Sat 19 Nov, 2011 18:35
Posts: 2126

  Z3 roadster 1.9

Re: Polybush help in North West

Post by Del » Sat 31 Oct, 2015 23:11

Tramlining is where it feels as if the front wheels/steering are following ruts in the road - for example on the inner lane on worn motorways where the lorries make slight sunken channels. Is that what you are experiencing? Tramlining is not necessarily linked to just acceleration - if the rear of the car feels that it is bouncing down and up on acceleration - it could be worn shock absorbers.

The problem with Z3s is that now that they are quite old cars, there are numerous items on the underside that could be "tired" and causing slight issues. The most common issues are probably tired shock absorbers and the rubber bush at the back of the front control arm, worn ball joints tend to get picked up at MOTs. There are also large sub-frame bushes at the ends of the rear sub-frame which, if badly worn, can cause a certain feeling of vagueness under acceleration. The main cause of most simple tramlining issues (if it is tramlining you are experiencing) is the choice of tyres - some tyres seem to make it worse. I've kept an eye on the tyres mentioned for curing Z3 tramlining and Avon ZV5 has been mentioned more than most.

If you decide to go down the route of fitting poly bushes, the most commonly recommended brand is Powerflex - the recommended type for road use is their purple range which I've not found too hard/harsh - they are said to be about 30% harder than the OE rubber ones.

Dva99999
Joined: Mon 28 Sep, 2015 20:58
Posts: 7

  Z3 roadster 2.8

Re: Polybush help in North West

Post by Dva99999 » Sun 01 Nov, 2015 10:05

peter2b wrote:I tnink it might have some thing to do with the tyres do a search on this site might show some thing,I have a man shed with a twin arm car lift if you need it over a week end
peter2b
Thanks Peter, I may just take you up on that.

Seems if I want to use Powerflex bushes there are some things I need to check first so I get the right ones. I'll check to see which tyres are on there. I have garage safe to jack the car up but only so far so will report back.

Thanks all for your help
D

Fender2004
Joined: Fri 14 Aug, 2009 11:24
Posts: 878

  Z3 roadster 2.8
Location: Houghton-Le-Spring

Re: Polybush help in North West

Post by Fender2004 » Sun 01 Nov, 2015 10:29

If you decide to go down the Powerflex route I've heard that the ride is a lot stiffer if that is what you want then fine. Even replacing the original rubber bushes will make a big difference, as the ones on the car will be worn by now. It's down to how you want the car to drive like.
Image

Mike Fishwick
Joined: Fri 19 Jun, 2009 11:27
Posts: 1991

  Z3 roadster 2.8
Location: Daglan, France

Re: Polybush help in North West

Post by Mike Fishwick » Sun 01 Nov, 2015 15:22

Which part of my article did you not understand? I thought it was clear enough, but maybe I could do better!
A Z3 is not just for Christmas - it's for life!

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pingu
Joined: Fri 30 Apr, 2004 17:01
Posts: 3343

  M roadster S50

Re: Polybush help in North West

Post by pingu » Sun 01 Nov, 2015 23:13

Is the car standard?

Stock/aftermarket suspension?
Stock/aftermarket wheels?
What tyres have you have? Brand, size, pressures, tread?
Pingu

Dva99999
Joined: Mon 28 Sep, 2015 20:58
Posts: 7

  Z3 roadster 2.8

Re: Polybush help in North West

Post by Dva99999 » Tue 03 Nov, 2015 01:52

Mike Fishwick wrote:Which part of my article did you not understand? I thought it was clear enough, but maybe I could do better!
It's not you Mike, it's me. I'm a complete novice when it comes to car maintenance, and consider spark plug and oil change a good days work!
However I'll give anything a try if there's pictures and words!

Cheers

srichards
Joined: Sun 11 Oct, 2015 09:24
Posts: 61

  Z3 roadster 2.8

Re: Polybush help in North West

Post by srichards » Tue 03 Nov, 2015 09:35

If you don't mind going into another country then Demon Tweeks in Wrexham seem to know a reasonable amount about suspension set up. Alignment and tyre choice seem to be the big two that make the difference according to them. I'm booked in with them to cure my tramlining as frankly the car is scary on poor surfaces. I've had other cars tramline but they never feel so out of control and unsettled.

I think polybush make some bushes in 3 different levels so you have comfort, performance and rock hard motorsport type of set up. I've had some powerflex wishbone bushes. Ride seems a bit firmer.

I've been to Demon Tweeks. They re-checked alignment and tweaked it slightly. It is definitely more stable.

For tramlining they suggest new tyres. They suggested Falkens instead once I've worn the goodyears out :) Toyo proxies seem to be another make that they BMWs seem to dislike from what they said.

Apart from replacing suspension bushes with powerflex ones they also suggested Eibach Pro springs all round. They're progressive so shouldn't be too firm but they should make the car more settled over poor surfaces.

I've stuck with the alignment for now. New springs are about £55 a corner plus fitting which seems reasonable.

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