Coupe tramlining

UK forum for general and technical discussion about the Z3 roadster
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kkkrisss
Joined: Thu 13 Jan, 2011 09:15
Posts: 189

  Z3 roadster 1.8
Location: Munich

Coupe tramlining

Post by kkkrisss »

Juts out of curiosity does the Z3 Coupe suffer from the roadster tramlining issues or it is much more stiff?
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c_w
Joined: Thu 19 Aug, 2004 16:50
Posts: 4032

  M roadster S50

Re: Coupe tramlining

Post by c_w »

No real tramling on my M Coupe. If you mean the regular Z3 Coupes then it would be an interesting comparison - I suspect by comparison with the Roadster they don't suffer as much.
4wheels
Joined: Sat 24 Sep, 2016 19:42
Posts: 83

  Z3 roadster 3.0i

Re: Coupe tramlining

Post by 4wheels »

Can you be more specific as to what you mean by tramlining?
To me I've only had this ever on motorways in lane one?
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BladeRunner919
Joined: Fri 17 Feb, 2012 20:18
Posts: 2225

  Z3 roadster 1.9

Re: Coupe tramlining

Post by BladeRunner919 »

There are so many potential causes of tramlining that you would need a coupe and a roadster on fresh suspension, with the same tyres to make a comparison as to whether the chassis rigidity comes into play. Tramlining is generally a function of suspension, tyre make, tyre wear, etc, etc, so I doubt you could generalise that one would be better than the other.

My roadster doesn't suffer from tramlining so, to answer the question simply, a coupe can't be better than no tramlining.
4wheels
Joined: Sat 24 Sep, 2016 19:42
Posts: 83

  Z3 roadster 3.0i

Re: Coupe tramlining

Post by 4wheels »

So you mean wandering around on a straight Road?
Or just over bumps?

Do they tend to have bump steer?
kkkrisss
Joined: Thu 13 Jan, 2011 09:15
Posts: 189

  Z3 roadster 1.8
Location: Munich

Re: Coupe tramlining

Post by kkkrisss »

on a smooth road it is ok but on uneven roads it tends to steer
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BladeRunner919
Joined: Fri 17 Feb, 2012 20:18
Posts: 2225

  Z3 roadster 1.9

Re: Coupe tramlining

Post by BladeRunner919 »

There are many threads on tramlining and the causes tend to be one of, or a combination of, tyres, suspension, bushes, balljoints or tracking. New tyres seems to be the most common resolution.

If you have a square setup, you could try swapping the wheels front-to-back as a no-cost experiment.
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Robert T
Site Admin
Joined: Mon 12 Jun, 2006 10:35
Posts: 10170

  Z3 roadster 1.9
Location: Cheshire

Re: Coupe tramlining

Post by Robert T »

Definition is given here: https://en.wikipedia.org/wiki/Tramlining

In the case of the zeds, I have had it when driving over white lines on the road - you can actually feel the steering pull as the tyres touch the lines. You may also feel it on the rutted inside line on the motorway, where the car will not want to leave the ruts.

I wouldn't expect any difference in the behaviour of the coupe vs. the same model roadster, as the front-ends are identical. The ///M suspension seems to be better setup to avoid tramlining, so the ///M Coupe will likely handle better than the non-M variants.

Cheers R.
Arctic Silver '99 Z3 1.9 & Black '59 Frogeye 1275cc
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4wheels
Joined: Sat 24 Sep, 2016 19:42
Posts: 83

  Z3 roadster 3.0i

Re: Coupe tramlining

Post by 4wheels »

Thought that is what you all meant...
umm all cars do it to some degree, like the wiki link says some are worse than others.

its impossible to make cars ignore the bumps and grooves in the road.

why do you think racing cars go over the kerbs? its because they want the effect of the kerb to pull the car around the corner.

My Audi S4 is worse... but wase better than the Focus ST i had.... the stupid pug 206 had none.. hmmmmm lol :)
therealdb1
Joined: Tue 25 Jun, 2013 21:47
Posts: 263

  Z3 roadster 2.0

Re: Coupe tramlining

Post by therealdb1 »

And I thought for my 30 years of racing I was running the kerbs to shorten the lap!

Saves turning the steering wheel and balancing the back end on the throttle I suppose.

Live and learn, eh? :)
4wheels
Joined: Sat 24 Sep, 2016 19:42
Posts: 83

  Z3 roadster 3.0i

Re: Coupe tramlining

Post by 4wheels »

maybe i should have said some kerbs... usually slow ones....lol
Del
Joined: Sat 19 Nov, 2011 18:35
Posts: 2136

  Z3 roadster 1.9

Re: Coupe tramlining

Post by Del »

On an identical, like-for-like basis, I would be sure that the Z3 Coupe would generally handle better than its Roadster counterpart and that the Stig would get around the Nurburgring more quickly in the Z3 Coupe. :D However, I’m not convinced that the specific characteristic of tramlining is solely a Roadster issue. The two things that seem to aggravate this Z3 issue are firstly soft/worn bushes and secondly, certain tyres. Tyres seem to crop up most as the cause.
NZ00Z3
Joined: Thu 23 Jun, 2016 01:26
Posts: 95

  Z3 roadster 3.0i

Re: Coupe tramlining

Post by NZ00Z3 »

Having sorted several Z3's tramlining problems,

First make sure you have good new (under 6 year old tires on the front)

Second, change is the front control arm rear rubber bushings. Don't use the standard Z3 bushings, use the Z3M bushing. It has more rubber and makes a far stiffer connection to the car that reduces the tramlining. Some people use Poly bushings. I don't race or auto X so stick to rubber bushings.

There are other items that can be changes but these make the biggest change.
alec.m
Joined: Tue 05 Oct, 2010 19:01
Posts: 552

  Z3 roadster 2.8
Location: Lymington

Re: Coupe tramlining

Post by alec.m »

NZ00Z3 wrote:Having sorted several Z3's tramlining problems,

First make sure you have good new (under 6 year old tires on the front)

Second, change is the front control arm rear rubber bushings. Don't use the standard Z3 bushings, use the Z3M bushing. It has more rubber and makes a far stiffer connection to the car that reduces the tramlining. Some people use Poly bushings. I don't race or auto X so stick to rubber bushings.

There are other items that can be changes but these make the biggest change.
Totally agree with the above. In my experience if you`ve had bad tramlining it affects the wear on the front tyres and fitting polybushes will improve it no end but unless you replace the front tyes it will still be there to some degree. Any wear in any of the ball joints will also have an effect.
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