Z4MR Damping...

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OffdutyRockstar

Member
I have a quick question regarding the damping of the M roadster... I find the car incredibly incapable over lumpy, bumpy roads to the extent that you just cannot enjoy driving it nor put the power down effectively with every rut throwing the steering off kilter. :(

Aside from a pricey full coilover kit, is there a recommended spring or damper or combined setup which makes the car more useable on British B roads?
 
Have you checked your bushes?
Just had mine done (fronts), makes a big difference in terms of how it plants itself to the road.
and takes quite a bit of the road roughness away.
otherwise, dunno....
 
Is that dealer price Gannet?

I paid my indie £150. Using Lemforder bushes. £70 for the bushes and 1.5hrs labor.

Lemforder manufacture all BMW bushes. So they are the same, but don't come via BMW.

Was tempted to get powerflex, but was advised that because they are solid poly, they tend to be much harder on the ride (but will last longer).

only driven on them for an hour or so. but the ride is less harsh, and the car feels altogether tighter.

oh and a tell tale sign of warn bushes:
if you park up and try and wiggle your front wheel forward and back. if it shifts about; that generally means your bushes aren't gripping the wishbone as well as they could.

hope that helps.
 
Excellent advice I will check that out tomorrow. 8)

So over poor surfaces now you can keep the steering nice and straight? And throttle travel isn't impeded by massive airtime/ inertia? :)
 
It's certainly much better than it was, but it still tramlines (pulls in both directions) on some surfaces. But it's less pronounced now.

It's an issue I've been trying to get to the bottom of for a while with my zed. Harsh/crashing over bumps, pulling steering on rough surfaces etc

My plan next is; new front tyres (mine are badly worn), and then 4 wheel alignment.

I think low profile tyres on big rims doesn't help either.

In terms of airtime from bumps and holes, new bushes should help. what mileage have you done?

I've read that Z4 and 3 series bushes start going after 30k.

In terms of the wiggle test, this rather crude video shows what i mean. maybe don't kick them, but shift them with your hands:
http://www.youtube.com/watch?v=IxjFH4k65aM

here's a handy video showing where/what the front bushes are:
http://www.youtube.com/watch?v=LXoBRKQeT44

I'll stop now. good luck. let us know how you get on.
 
Be careful with some of the Lemforder stuff, as while they make plenty of parts for BMW with BMW spec materials, they also make aftermarket parts to varying standards too.

For example, the average BMW Lemforder wishbone for an e34 M5 lasts 100,000 miles (i.e. the original one fitted at the factory), whereas the replacement non-BMW part have lasted as little as 20,000 miles compared to replacement BMW ones that have not failed after another 60,000 miles.

However, to caveat that, there are also instances where the aftermarket Lemforder part has lasted longer than BMW-sourced versions.

Sometimes it's simply a case where BMW have used aluminium in their part and Lemforder have done their own with steel. The aluminium one is lighter and works well in an ///M car, but it's not necessarily good for longevity.

BTW, the e34 M5 is very hungry when it comes to bushes, and at every service (12,000 mile major service intervals) you'd be replacing one pair or another.
 
yes a dealer price, was a big gulp but the likes of National tyres etc wouldnt go near it cos of alignment concerns :?

my car is on just 48.5k miles.

the comment the replacing dealer said was that while it would have passed the MOT on the day of replacement it would have got an advisory.

I don't have tramlining at all on my car since I changed the tyres to Michelin ZP - probably not an issue for the OP though cos theirs is an M. But I do know what they mean about having to 'hang on' on bumpy roads but I havent really pushed it since having the bushes done cos my brakes also needed doing and didnt want to end up in the hedge! Once I have the new brakes bedded in I'll try some back roads again :)
 
I think my bushes will almost definitely need doing, the car is on 48k and the documentation suggests they have never been done...

My tyres are also quite crap atm, Dunlop SP Sports on the rear (really poor tyre imho, simply cannot submit the traction to any surface wet or dry AND they have plenty of tread), one Bridgestone RE040 on the N/S front and one Contisport on the O/S front... the car pulls strongly to the left which as I understoof is quite a common thing with E85's...

Original plan was to put up with this set of rubber in the dry months and then to sell the wheels and tyres in a few months for CSL's with my favourite performance tyre, Eagle F1 GSD3s. But I dont want to go down the 19" wheel route if it will simply serve to exacerbate the ride issues? Dynamically I was planning on a front strut brace very soon and 4 wheel alignment to try and relieve the tramlining.

So I guess the next question is, does anyone with CSL's find the ride harder and the damping even poorer then before?

Really appreciate all the advice normski... incidentally you arent the DJ normski are you? Because if you are then I have met you a few times. :D
 
I put CSLs on my MR about 3 weeks ago and I honestly find the ride better, particularly around town. It just seems to ride the bumps a bit more smoothly. No problems with tramlining either on the motorway.

I had to retorque the wheels to smooth out some initial judder issues but these have gone and I'll never look back! :driving: I fit a set of Vredesteins on 235/35 265/30 and they run beautifully, particularly in the wet where my old M3 contis were quite prone to aquaplaning :thumbsdown:

I don't have any damping issues but my car has only just hit 26k so a fair few miles behind...
 
I think good tyres can negate an inch less worth of sidewall and for the traction and aesthetic benefits I will likely still go for CSLs in a couple of months. 8)

Have called my local indy for a price on new control arm bushes all round, lets see what he can come up with..
 
Cool, for an idea of how damn 8) a sapphire black MR looks with CSLs take a look in the gallery . I posted up some pics the other day. Be warned though, I think this modding thing can be addictive!
 
Car looks great lazer 8)

I have a quote from a very reputable indy, £193 supplied and fitted for front control arm bushes using OEM BMW parts, good?

I'm going to get it booked in together with fitting my strut brace and CDV delete. 8)
 
Normski as in this guy?
http://www.croydonsummerfestival.org/img/artists/Normski.jpg

Sadly I'm a slightly overweight white guy! :lol:

Price sounds about right OffDutyRockstar. So I think the general consensus is that a combination of wheels, tyres, alignment and bad bushes all add up to a twitchy ride.
 
Yes that guy! I work in the clubs around London's West End and run into him regularly, nice fella but talks way too much :rofl:

Ok so I parked up the car with the handbrake applied and gave the front wheels a little wiggle with by grabbing the tyre... I cant say I noticed alot of movement, maybe rotation wise there was a little but I was applying nowhere near as much force as kicking it in that video above (and didnt want to tbh), there was a telltale squeak however from somewhere within the suspension... So do my bushes need doing? Like I said, 48k and I believe they've never been done...

While I was at it I checked the rear arch clearance for discrepencies that may point towards broken springs and it seems uniform from one side to the other however the actual arch clearance is alot smaller then the front, 1 and 3 quarter fingers as opposed to about 2 and 3 quarters for the fronts, again is this normal? :|
 
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