The M3cutters - UK BMW M3 Group Forum
 

Go Back   The M3cutters - UK BMW M3 Group Forum > M3 and M4 Talk > F80 M3 Saloon / F82 M4 Coupe / F83 M4 Convertible



Reply
 
Thread Tools Display Modes
Old 7th December 2017, 07:30 AM   #1
lindorez
Wearing official underwear
 
lindorez's Avatar
 
Join Date: Apr 2015
Posts: 260
Car: BMW F82 M4 ZCP
Default Rear End Twitch - Any Ideas?

I've been having this intermittent issue with my car and wanted to know if anybody else has had this before.

At lower speeds 30mph or less (usually on a round about) the backend will kick side to side and then regain traction. The only way I can describe it is that it feels like the brakes were slammed on the rear at one side of the car it kicks the car out and then its released again and drives fine.

- There is no traction control light on when it happens, sometimes this does come on afterwards as the car is unsettled but not every time.
- I initially thought it was when in automatic mode and unexpected change of gear unsettled the rear but it happened to me in manual mode a couple of times now.
- I checked the rear brakes and doesn't look to be anything touching that could knock against the discs unnecessarily.
- It's always at a reasonable speed and not under heavy acceleration. Its happened mainly in efficient mode but also a couple of times in sports mode. So its not me pushing the car to the limits and an actual drift. I've done this before and its a very different feeling.
- I've been back and checked the road surface afterwards a few times and never any issue so its not a spillage, cold weather etc
- Its happened with both my Michelin MPSS and Michelin Alpines which have loads of tread so its not the tyres.

As this is intermittent and I can't show the garage and I doubt it would happen to them on a test drive. It has happened maybe 10 times in my 2 years ownership.

The car generally performs great but I always have this concern it is going to do this at either a higher speed or when another car is around. It happened just turning on a roundabout yesterday and an Audi was right up my arse, it got a fright and so did I as it was almost into the back of me.

Anybody had this issue before or any ideas?
lindorez is offline   Reply With Quote
Sponsored links
Old 7th December 2017, 08:15 AM   #2
caterham7
Wearing official robes
 
caterham7's Avatar
 
Join Date: Jan 2012
Posts: 321
Car: 2016 m4
Default

just sounds like the rear is losing traction slightly, could be due to too much throttle, or too much steering angle (or both).

You dont have to have your foot anywhere near the floor to break traction (even with traction control fully on), just the right (or wrong depending on your point of view) combination of camber of surface, road temperature,throttle and steering input.

Roundabouts are usually where this will happen for me, on the transition where the road camber changes where you exit a roundabout, slightly too much throttle in combination with a bit too much steering angle will see the back slide at less than 30 mph even with the TC on.
caterham7 is offline   Reply With Quote
Old 7th December 2017, 08:45 AM   #3
Muu
Wearing official underwear
 
Muu's Avatar
 
Join Date: May 2017
Posts: 248
Car: 2017 M3 CP
Default

What are the tyre pressures at?
Muu is offline   Reply With Quote
Old 7th December 2017, 09:12 AM   #4
lindorez
Wearing official underwear
 
lindorez's Avatar
 
Join Date: Apr 2015
Posts: 260
Car: BMW F82 M4 ZCP
Default

Quote:
Originally Posted by caterham7 View Post
just sounds like the rear is losing traction slightly, could be due to too much throttle, or too much steering angle (or both).

You dont have to have your foot anywhere near the floor to break traction (even with traction control fully on), just the right (or wrong depending on your point of view) combination of camber of surface, road temperature,throttle and steering input.

Roundabouts are usually where this will happen for me, on the transition where the road camber changes where you exit a roundabout, slightly too much throttle in combination with a bit too much steering angle will see the back slide at less than 30 mph even with the TC on.
Thanks for the advice. It is possible but 90% of the time it is on roads I know and drive every day.

I am very good at regulating the throttle - in the last incident I was at most 20% throttle in efficient mode when it happened.

I have experience in powerful rear wheel drive cars and I only mash the throttle in proper conditions so.

Quote:
Originally Posted by Muu View Post
What are the tyre pressures at?
I have the 20" comp pack wheels - 2.3psi front and 2.1psi rear. Fluctuates with the cold weather plus or minus 0.1 psi
lindorez is offline   Reply With Quote
Old 7th December 2017, 09:46 AM   #5
Billyali86
Rocking a new hat
 
Billyali86's Avatar
 
Join Date: Mar 2014
Posts: 511
Car: M4 - Yas Marina
Default

Alingment maybe ? I recently had my m4 returned to stock with springs included. Didn't get a chance get alignment sorted before it was being traded in.

Felt like a totally different car, to the point I was actually scared to drive the damn thing
Billyali86 is offline   Reply With Quote
Old 7th December 2017, 11:47 AM   #6
lindorez
Wearing official underwear
 
lindorez's Avatar
 
Join Date: Apr 2015
Posts: 260
Car: BMW F82 M4 ZCP
Default

Quote:
Originally Posted by Billyali86 View Post
Alingment maybe ? I recently had my m4 returned to stock with springs included. Didn't get a chance get alignment sorted before it was being traded in.

Felt like a totally different car, to the point I was actually scared to drive the damn thing
I had thought that myself but had an alignment done on a hunter system and car is straight as an arrow. It has happened since then.
lindorez is offline   Reply With Quote
Old 7th December 2017, 11:53 AM   #7
Melvyn
Achieved official socks
 
Melvyn's Avatar
 
Join Date: Jan 2014
Posts: 8,424
Car: F13M6 CP Silverstone2 with MPE that don't break
Default

What depth are the tyre tread
Melvyn is offline   Reply With Quote
Old 7th December 2017, 12:29 PM   #8
lindorez
Wearing official underwear
 
lindorez's Avatar
 
Join Date: Apr 2015
Posts: 260
Car: BMW F82 M4 ZCP
Default

Quote:
Originally Posted by Melvyn View Post
What depth are the tyre tread
MPSS are 7mm front 6mm rear
Alpine are 7mm front 6.5mm rear
lindorez is offline   Reply With Quote
Old 7th December 2017, 01:00 PM   #9
Schuey
Achieved official socks
 
Schuey's Avatar
 
Join Date: Mar 2013
Posts: 4,282
Car: 2017 BMW F82 M4 Comp Pack
Colour Combo: YMB / SS
Default

Quote:
Originally Posted by lindorez View Post



I have the 20" comp pack wheels - 2.3psi front and 2.1psi rear. Fluctuates with the cold weather plus or minus 0.1 psi
Why are you running higher pressures on the front? Typically the rears should be 0.1 more than the fronts.

I run 2.1 bar fronts, 2.2 bar rears.
Schuey is offline   Reply With Quote
Old 7th December 2017, 01:34 PM   #10
lindorez
Wearing official underwear
 
lindorez's Avatar
 
Join Date: Apr 2015
Posts: 260
Car: BMW F82 M4 ZCP
Default

Quote:
Originally Posted by Schuey View Post
Why are you running higher pressures on the front? Typically the rears should be 0.1 more than the fronts.

I run 2.1 bar fronts, 2.2 bar rears.
Well I personally thought that but BMW recommend 2.4 front and 2.1 rear for the comp pack wheels on the door sticker. The 19's are recommended as a 2.2 square setup.
lindorez is offline   Reply With Quote
Old 7th December 2017, 04:20 PM   #11
antych
Achieved official socks
 
antych's Avatar
 
Join Date: Apr 2015
Location: London
Posts: 697
Car: 2017 BMW M4 CP
Colour Combo: Sakhir Orange / Black
Default

It was always 2.2-2.4 bar depending on the load, CP or not.
antych is offline   Reply With Quote
Old 7th December 2017, 05:26 PM   #12
lindorez
Wearing official underwear
 
lindorez's Avatar
 
Join Date: Apr 2015
Posts: 260
Car: BMW F82 M4 ZCP
Default

Quote:
Originally Posted by antych View Post
It was always 2.2-2.4 bar depending on the load, CP or not.


Had a look at my sticker

2.2 - 2.2 for 19"
2.4 - 2.1 for 20"
lindorez is offline   Reply With Quote
Old 7th December 2017, 05:29 PM   #13
Melvyn
Achieved official socks
 
Melvyn's Avatar
 
Join Date: Jan 2014
Posts: 8,424
Car: F13M6 CP Silverstone2 with MPE that don't break
Default

Quote:
Originally Posted by lindorez View Post
MPSS are 7mm front 6mm rear
Alpine are 7mm front 6.5mm rear
Not that then buddy, reason I asked was that these M cars start to let go at around 4 mill
Melvyn is offline   Reply With Quote
Old 7th December 2017, 05:48 PM   #14
Singh21
Achieved official socks
 
Singh21's Avatar
 
Join Date: Nov 2014
Location: Hitchin
Posts: 2,267
Car: Bmw m4
Colour Combo: MW / SO
Default

I had this exact same thing. I thought it may be my diff as it was pulling over every little bump at low speed and in the wet was pulling all over the place.

What sorted it for me was an alignment. Get it done at a good place and then see after.
Singh21 is online now   Reply With Quote
Old 7th December 2017, 07:13 PM   #15
E46CoupeM3
Achieved official socks
 
E46CoupeM3's Avatar
 
Join Date: Oct 2012
Location: England
Posts: 12,965
Car: 2001 BMW M3
Colour Combo: Carbon Black
Default

Quote:
Originally Posted by Melvyn View Post
Not that then buddy, reason I asked was that these M cars start to let go at around 4 mill
If it's dry less tread is better as less block flex. Only worse if insufficient to clear water, so better in damp too.
E46CoupeM3 is offline   Reply With Quote
Old 7th December 2017, 07:30 PM   #16
Melvyn
Achieved official socks
 
Melvyn's Avatar
 
Join Date: Jan 2014
Posts: 8,424
Car: F13M6 CP Silverstone2 with MPE that don't break
Default

Quote:
Originally Posted by E46CoupeM3 View Post
If it's dry less tread is better as less block flex. Only worse if insufficient to clear water, so better in damp too.
Not according to my flashing yellow gremlin


Your right of course , putting heat into them will make them stick, just wrong season to do so
Melvyn is offline   Reply With Quote
Old 7th December 2017, 07:34 PM   #17
antych
Achieved official socks
 
antych's Avatar
 
Join Date: Apr 2015
Location: London
Posts: 697
Car: 2017 BMW M4 CP
Colour Combo: Sakhir Orange / Black
Default

Quote:
Originally Posted by lindorez View Post
Had a look at my sticker

2.2 - 2.2 for 19"
2.4 - 2.1 for 20"
That looks different than mine. I have 2.2 - 2.2 for 20"
antych is offline   Reply With Quote
Old 7th December 2017, 07:40 PM   #18
E46CoupeM3
Achieved official socks
 
E46CoupeM3's Avatar
 
Join Date: Oct 2012
Location: England
Posts: 12,965
Car: 2001 BMW M3
Colour Combo: Carbon Black
Default

Quote:
Originally Posted by Melvyn View Post
Not according to my flashing yellow gremlin


Your right of course , putting heat into them will make them stick, just wrong season to do so
Nope, less block flex = better grip heat regardless, unless too much standing water to clear. Block flex actually generates heat too and is one of the reasons treads aren't deeper
E46CoupeM3 is offline   Reply With Quote
Old 7th December 2017, 08:23 PM   #19
jpf
Achieved official socks
 
jpf's Avatar
 
Join Date: Aug 2014
Posts: 2,704
Car: M4
Colour Combo: Austin Yellow/ full black leather
Default

Quote:
Originally Posted by Melvyn View Post
Not according to my flashing yellow gremlin


Your right of course , putting heat into them will make them stick, just wrong season to do so
Managed to get good heat into my crazy Atom's nearly worn out (2.5 - 2.9mm) Yokohama AD08 tyres yesterday. Those tyres are truly amazing once warmed up. Went out today for a short blast, completely different story spinning tyres everywhere which is of course highly amusing.
jpf is offline   Reply With Quote
Old 7th December 2017, 09:32 PM   #20
lindorez
Wearing official underwear
 
lindorez's Avatar
 
Join Date: Apr 2015
Posts: 260
Car: BMW F82 M4 ZCP
Default

Quote:
Originally Posted by antych View Post
That looks different than mine. I have 2.2 - 2.2 for 20"
That is very strange. I have no idea why they would differ - Perhaps that could be part of the issue.

Might try set the pressure to 2.2 - 2.2.
lindorez is offline   Reply With Quote
Reply

Bookmarks


Thread Tools
Display Modes



All times are GMT. The time now is 02:12 AM.


This website uses cookies. By continuing to use the site you are agreeing to our use of cookies. To find out more about the cookies this website uses, click here.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright © 2007 - 2014 M3cutters. All Rights Reserved.