Not joined yet? Register for free and enjoy features such as alerts, private messaging and viewing latest posts and topics.

Twitchy rear end...

Specific discussion about the E89 2009 Z4 (sDrive35is, sDrive35i, sDrive30i, sDrive23i)
syyzed
Newbie
Newbie
Posts: 40
Joined: Sat Jun 02, 2018 9:35 am

Twitchy rear end...

Post by syyzed » Sun Nov 04, 2018 10:22 pm

Hi Guys,

So as of late, my zed’s handling hasn’t been inspiring the most amount of confidence, the car is feeling twitchy, finding every pothole or divot in the road and tram-lining at every given opportunity :thumbsdown:

I was just wondering if this a common trait with the dreaded run flats currently fitted to my car or if maybe a simple tyre pressure adjustment would help settle it a bit? (currently running the recommended 33 front, 40 rear, which seems a little high for uk roads imo) :headbang:
E89 Z4 2.8i M Sport.

Online
User avatar
buzyg
Legend
Legend
Posts: 26536
Joined: Fri May 20, 2011 6:11 pm
Location: Cornwall

Twitchy rear end...

Post by buzyg » Sun Nov 04, 2018 10:46 pm

Apparently they all d it. :o Ditch the run flats and enjoy :driving: .

Oh and less of those strong curries might help too. :wink:
Image

syyzed
Newbie
Newbie
Posts: 40
Joined: Sat Jun 02, 2018 9:35 am

Twitchy rear end...

Post by syyzed » Sun Nov 04, 2018 10:52 pm

buzyg wrote: Sun Nov 04, 2018 10:46 pm Apparently they all d it. :o Ditch the run flats and enjoy :driving: .

Oh and less of those strong curries might help too. :wink:


Haha, ill steer clear of those curry's for now, Saturday nights will never be the same though..

Its weird, I have only just started noticing it and i have had the car over a year now :( . I will be ditching them as soon as I can for pilot sports but for now, I was just wondering if maybe a simple tyre change and some alignment might make things a bit more bearable you know
E89 Z4 2.8i M Sport.

Busterboo
Senior Member
Senior Member
Posts: 2811
Joined: Sun Nov 20, 2016 2:49 am

Twitchy rear end...

Post by Busterboo » Mon Nov 05, 2018 12:14 am

syyzed wrote: Sun Nov 04, 2018 10:52 pm I was just wondering if maybe a simple tyre change and some alignment might make things a bit more bearable you know
It will and not just "a bit more bearable", but very good.

Runflats on Z4s are the Devil's work.
Vidi, vici, veni

User avatar
R60BBA
Senior Member
Senior Member
Posts: 1776
Joined: Sat Sep 30, 2017 7:53 pm
Location: London, United Kingdom

Twitchy rear end...

Post by R60BBA » Mon Nov 05, 2018 2:21 am

40 rear is too high.

Too high a tyre pressure = darty/twitchy handling.

Drop the pressure down to 36 on the rears.
Current: 2002 E46 M3
Current: 2005 997 Carrera S
Gone: 2004 R53 Cooper S
Gone: 1998 E31 840Ci Sport
Gone: 2007 Z4 E86 3.0Si Sport
Gone: 2001 Z3 E36/7 2.2i San Remo Individual
Gone: 2015 F21 116d M Sport
Gone: 2012 A3 Sportback 1.2TFSI

Rathean
Member
Member
Posts: 133
Joined: Thu May 19, 2016 10:49 pm

Twitchy rear end...

Post by Rathean » Mon Nov 05, 2018 9:26 am

Busterboo wrote: Mon Nov 05, 2018 12:14 am
syyzed wrote: Sun Nov 04, 2018 10:52 pm I was just wondering if maybe a simple tyre change and some alignment might make things a bit more bearable you know
It will and not just "a bit more bearable", but very good.

Runflats on Z4s are the Devil's work.
Yeah this. I had Runflats on for a couple of years, kicking myself for not swapping out to Pilot Sports earlier but the difference, well, it's like driving a different car with much improved handling and ride quality :driving:
2011 X3 30d MSport black, 8-speed auto, leather everything
2011 Bimmer Z4 35i diamond black, 6-speed manual, full caboodle (hibernating) :driving:

Online
User avatar
Phoenixboy
Senior Member
Senior Member
Posts: 2117
Joined: Fri Nov 11, 2016 9:07 pm
Location: english riviera

Twitchy rear end...

Post by Phoenixboy » Mon Nov 05, 2018 2:38 pm

R60BBA wrote: Mon Nov 05, 2018 2:21 am 40 rear is too high.

Too high a tyre pressure = darty/twitchy handling.

Drop the pressure down to 36 on the rears.
So what pressures are you suggesting on run flats then?
E89 s drive 30i manual/gone
space grey
Carbon interior trim
19" Veeman FS 25`s
cruise control
m sport seats
stubby
led halo bulbs
z4 forum sticker, for added power.
OEM wind deflector
Gone, E85 Ruby Black.

Busterboo
Senior Member
Senior Member
Posts: 2811
Joined: Sun Nov 20, 2016 2:49 am

Twitchy rear end...

Post by Busterboo » Mon Nov 05, 2018 4:30 pm

R60BBA wrote: Mon Nov 05, 2018 2:21 am 40 rear is too high.

Too high a tyre pressure = darty/twitchy handling.

Drop the pressure down to 36 on the rears.
On your 2002 BMW 3 SERIES M3, perhaps, but not necessarily on a Z4.
Vidi, vici, veni

User avatar
Player 1
Member
Member
Posts: 322
Joined: Sat Aug 09, 2014 9:34 pm
Location: Cornwall

Twitchy rear end...

Post by Player 1 » Mon Nov 05, 2018 5:32 pm

Busterboo wrote: Mon Nov 05, 2018 4:30 pm
R60BBA wrote: Mon Nov 05, 2018 2:21 am 40 rear is too high.

Too high a tyre pressure = darty/twitchy handling.

Drop the pressure down to 36 on the rears.
On your 2002 BMW 3 SERIES M3, perhaps, but not necessarily on a Z4.
Exactly, BMW aren't stupid. If the recommended pressure was really as bad as the OP's describing, it wouldn't be the recommended pressure in the first place.

Sounds a lot like the alignment's taken a wander.
Image

User avatar
MrPT
Lifer
Lifer
Posts: 4746
Joined: Sun Oct 21, 2012 7:44 pm
Location: Bucks/Oxon

Twitchy rear end...

Post by MrPT » Mon Nov 05, 2018 6:57 pm

Changing tyre pressures is free and easy. Try it.
2008 Z4MC: heavy wheels | crap suspension | skittish rear end | wobbly engine | not enough induction noise | underwhelming turn in | inconsistent braking | lardy battery | chubby steering wheel
2006 Z4 2.5si: gone

User avatar
Silverzedtom
Senior Member
Senior Member
Posts: 1478
Joined: Sun Jan 15, 2017 8:19 pm
Location: East Sussex

Twitchy rear end...

Post by Silverzedtom » Mon Nov 05, 2018 7:24 pm

I’d check your shock absorbers and springs too.
E85 2.5si
F55 Cooper S

syyzed
Newbie
Newbie
Posts: 40
Joined: Sat Jun 02, 2018 9:35 am

Twitchy rear end...

Post by syyzed » Mon Nov 05, 2018 8:02 pm

Player 1 wrote: Mon Nov 05, 2018 5:32 pm
Busterboo wrote: Mon Nov 05, 2018 4:30 pm
R60BBA wrote: Mon Nov 05, 2018 2:21 am 40 rear is too high.

Too high a tyre pressure = darty/twitchy handling.

Drop the pressure down to 36 on the rears.
On your 2002 BMW 3 SERIES M3, perhaps, but not necessarily on a Z4.
Exactly, BMW aren't stupid. If the recommended pressure was really as bad as the OP's describing, it wouldn't be the recommended pressure in the first place.

Sounds a lot like the alignment's taken a wander.
Thanks, guys, ill try dropping the rear pressures now and ill let you know if that helps. I'm hoping its not anything more serious than that but we all know how these things go..
E89 Z4 2.8i M Sport.

Busterboo
Senior Member
Senior Member
Posts: 2811
Joined: Sun Nov 20, 2016 2:49 am

Twitchy rear end...

Post by Busterboo » Wed Nov 07, 2018 2:28 am

syyzed, you ain't going to get a decent ride 'til you dump the runflats.
Vidi, vici, veni

AveZ4coop
Member
Member
Posts: 399
Joined: Thu Nov 16, 2017 11:08 pm
Location: Peterborough

Twitchy rear end...

Post by AveZ4coop » Wed Nov 07, 2018 6:14 am

Busterboo wrote: Wed Nov 07, 2018 2:28 am syyzed, you ain't going to get a decent ride 'til you dump the runflats.
:thumbsup:
Montego blue 2006 BMW Z4 coupe 3.0si with black interior, ZHP, Whippy, 12mm front/16mm rear spacers on BBS 108's wrapped in Michelin PS4's. :driving:Brand new Pierburg water pump fitted at 101k after failure :cry: (should have done it at 100k) :headbang:

Hellequin
Member
Member
Posts: 84
Joined: Sun May 22, 2011 10:15 pm
Location: Ashtead, Surrey

Twitchy rear end...

Post by Hellequin » Wed Nov 07, 2018 1:57 pm

AveZ4coop wrote: Wed Nov 07, 2018 6:14 am
Busterboo wrote: Wed Nov 07, 2018 2:28 am syyzed, you ain't going to get a decent ride 'til you dump the runflats.
:thumbsup:
and they are quieter!
59 plate sDrive23i 2.5

Post Reply