Twitchy at higher speeds after alignment

JayL · 04-20-2017, 09:06 PM

I just got my car back from getting an alignment and it now feels very twitchy at higher speeds (75+ mph). Feels like the front turns instantly with very little steering input and then after a pause the rear quickly follows, almost to the point where I feel it will come all the way around if I was really driving hard. Not very confidence inspiring.

I'm thinking it's likely the toe because the camber is similar to what it's had in the past but wanted to get other thoughts. Should I go with different specs, look elsewhere for the cause or possibly just take it to another shop for a second opinion?

07 Z4M
KW v3 with Vorshlag camber plates
255/275 18s
Mixed track and street driving.

Any thoughts?

inTgr8r · 04-20-2017, 09:09 PM

Do you track your car?
The front camber is extreme unless you track it.

For street you could add some toe as well.

JayL · 04-20-2017, 09:13 PM

I forgot to add that part, yes I do track the car.

inTgr8r · 04-20-2017, 09:21 PM

What kind of mileage is on it?
Are the RTABs & FCABs still original?

JayL · 04-20-2017, 09:24 PM

67000 miles and the RTABs & FCABs are still original.

inTgr8r · 04-20-2017, 09:28 PM

Quote:

Originally Posted by JayL

67000 miles and the RTABs & FCABs are still original.

I can almost guarantee that they are toast.
The more extreme alignment exacerbates the situation.

JayL · 04-20-2017, 09:31 PM

Thank you, time for me to learn a about them and do the work.

The HACK · 04-20-2017, 11:53 PM

Zero toe and -3.2 degree of camber? Get used to it.

A friend and I were on our way to Spring Mountain, and on stretches we hit 120mph. At anything above 100 on relatively smooth surface street, the front end wanders and follows whatever rut and undulations that it became very taxing to keep the car straight. On the track it's straight as arrow up to 140. My buddy was wondering why I had trouble keeping up on the drive up. Frankly at cambers larger than -3, it gets darts and follows whatever imperfections there are in the road surface.

But we're talking triple digit speeds here. Up to about 90 it's rock solid.

JayL · 04-21-2017, 06:39 AM

The tramlining is something which doesn't really bother me and is something the car has always done. Pretty much every car I've built for the track over the past 10 years has had this trait. This definitely feels like something different but I've been wrong before.

After reading about FCABs and RTABs for a few hours last night I'm thinking they are likely the culprit, even if it isn't it will be good preventative maintenance.

dc_wright · 04-22-2017, 08:57 PM

I've been running zero toe in the front for a while and the car was a handful on the highway. No issues on the track, but the tracks aren't crowned and don't have ruts from tractor trailer rigs either. New front control arms/bushings and new RTABs tamed the tramlining on my car considerably. The control arm bushings were replaced at 60K miles, but the car is now at 96K and I think the combined wear in the ball joints and some degradation of the FCABs were the contributors.

JayL · 05-04-2017, 08:34 PM

Just a quick update, FCABs made zero difference but RTABs made a night and day difference.

Going to do one other change in the front to get additional caster and put a few miles on it before it goes back on the rack for another alignment. Likely won't be able to get the same camber up front but enough to keep me smiling.

inTgr8r · 05-04-2017, 09:07 PM

Good stuff!!

JayL · 05-12-2017, 10:23 PM

Raised the car 1/2 an inch and got an alignment yesterday. Along with the other changes, I feel this is a much better starting spot to tune the car to my driving style.

Front Camber: -2.3
Front Caster: 8
Front toe: .04

Rear Camber: -1.7
Rear Toe: .21

I'll drive it on the street for a bit and do a few track days before I make up my mind but so far it's better. Turn in is crisp while high speed stability inspires confidence. I think this is likely a better place to start from based on my own driving skills.

inTgr8r · 05-13-2017, 07:20 AM

Sounds good .
Alignment is a funny thing, there is so much going on with dependencies on how the rest of the car is set up.
I always like to tweek one thing at a time when I'm making changes.

doane2u · 06-09-2017, 08:41 PM

I just posted about a similar feeling with my 2007 E85 3.0i which has about 70k miles on it. At about 70-75mph it starts feeling sort of wonky, like there is a slight looseness in the steering which is really unsettling. Tires have only about maybe 3k miles on them. I've never had an alignment and don't feel any problems are any other speeds. As far as I know the car is stock.

Any thoughts?

04-20-2017, 09:06 PM	#1
JayL Enlisted Member 9 Rep 37 Posts Drives: Z4MC, X3 Join Date: Jul 2015 Location: Austin, TX iTrader: (0)	Twitchy at higher speeds after alignment I just got my car back from getting an alignment and it now feels very twitchy at higher speeds (75+ mph). Feels like the front turns instantly with very little steering input and then after a pause the rear quickly follows, almost to the point where I feel it will come all the way around if I was really driving hard. Not very confidence inspiring. I'm thinking it's likely the toe because the camber is similar to what it's had in the past but wanted to get other thoughts. Should I go with different specs, look elsewhere for the cause or possibly just take it to another shop for a second opinion? 07 Z4M KW v3 with Vorshlag camber plates 255/275 18s Mixed track and street driving. Any thoughts? Last edited by JayL; 04-20-2017 at 09:13 PM.. Reason: use of car
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04-20-2017, 09:09 PM	#2
inTgr8r Lieutenant General 2426 Rep 11,667 Posts Drives: M2 Comp Join Date: Mar 2006 Location: Toronto iTrader: (10)	Do you track your car? The front camber is extreme unless you track it. For street you could add some toe as well. __________________ '21 M2C Hockenheim Silver '18 718 Cayman S Lava Orange (sold) '13 E92 M3 Santorini Blue (sold) '07 Z4 M Coupe Alpine White (sold)
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04-20-2017, 09:13 PM	#3
JayL Enlisted Member 9 Rep 37 Posts Drives: Z4MC, X3 Join Date: Jul 2015 Location: Austin, TX iTrader: (0)	I forgot to add that part, yes I do track the car.
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04-20-2017, 09:21 PM	#4
inTgr8r Lieutenant General 2426 Rep 11,667 Posts Drives: M2 Comp Join Date: Mar 2006 Location: Toronto iTrader: (10)	What kind of mileage is on it? Are the RTABs & FCABs still original? __________________ '21 M2C Hockenheim Silver '18 718 Cayman S Lava Orange (sold) '13 E92 M3 Santorini Blue (sold) '07 Z4 M Coupe Alpine White (sold)
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04-20-2017, 09:24 PM	#5
JayL Enlisted Member 9 Rep 37 Posts Drives: Z4MC, X3 Join Date: Jul 2015 Location: Austin, TX iTrader: (0)	67000 miles and the RTABs & FCABs are still original.
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04-20-2017, 09:31 PM	#7
JayL Enlisted Member 9 Rep 37 Posts Drives: Z4MC, X3 Join Date: Jul 2015 Location: Austin, TX iTrader: (0)	Thank you, time for me to learn a about them and do the work.
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04-20-2017, 11:53 PM	#8
The HACK Midlife Crises Racing Silent but Deadly Class 1821 Rep 5,337 Posts Drives: 2006 MZ4C, 2021 Tesla Model 3 Join Date: Oct 2007 Location: Welcome to Jamaica have a nice day iTrader: (1)	Zero toe and -3.2 degree of camber? Get used to it. A friend and I were on our way to Spring Mountain, and on stretches we hit 120mph. At anything above 100 on relatively smooth surface street, the front end wanders and follows whatever rut and undulations that it became very taxing to keep the car straight. On the track it's straight as arrow up to 140. My buddy was wondering why I had trouble keeping up on the drive up. Frankly at cambers larger than -3, it gets darts and follows whatever imperfections there are in the road surface. But we're talking triple digit speeds here. Up to about 90 it's rock solid. __________________ Sitting on a beat-up office chair in front of a 5 year old computer in a basement floor, sipping on stale coffee watching a bunch of meaningless numbers scrolling aimlessly on a dimly lit 19” monitor.
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04-21-2017, 06:39 AM	#9
JayL Enlisted Member 9 Rep 37 Posts Drives: Z4MC, X3 Join Date: Jul 2015 Location: Austin, TX iTrader: (0)	The tramlining is something which doesn't really bother me and is something the car has always done. Pretty much every car I've built for the track over the past 10 years has had this trait. This definitely feels like something different but I've been wrong before. After reading about FCABs and RTABs for a few hours last night I'm thinking they are likely the culprit, even if it isn't it will be good preventative maintenance.
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04-22-2017, 08:57 PM	#10
dc_wright Captain 249 Rep 758 Posts Drives: 2006 Z43.0si Roadster Join Date: Oct 2014 Location: Orlando, FL iTrader: (0)	I've been running zero toe in the front for a while and the car was a handful on the highway. No issues on the track, but the tracks aren't crowned and don't have ruts from tractor trailer rigs either. New front control arms/bushings and new RTABs tamed the tramlining on my car considerably. The control arm bushings were replaced at 60K miles, but the car is now at 96K and I think the combined wear in the ball joints and some degradation of the FCABs were the contributors. __________________ Top Down 365
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05-04-2017, 08:34 PM	#11
JayL Enlisted Member 9 Rep 37 Posts Drives: Z4MC, X3 Join Date: Jul 2015 Location: Austin, TX iTrader: (0)	Just a quick update, FCABs made zero difference but RTABs made a night and day difference. Going to do one other change in the front to get additional caster and put a few miles on it before it goes back on the rack for another alignment. Likely won't be able to get the same camber up front but enough to keep me smiling.
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05-04-2017, 09:07 PM	#12
inTgr8r Lieutenant General 2426 Rep 11,667 Posts Drives: M2 Comp Join Date: Mar 2006 Location: Toronto iTrader: (10)	Good stuff!! __________________ '21 M2C Hockenheim Silver '18 718 Cayman S Lava Orange (sold) '13 E92 M3 Santorini Blue (sold) '07 Z4 M Coupe Alpine White (sold)
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05-12-2017, 10:23 PM	#13
JayL Enlisted Member 9 Rep 37 Posts Drives: Z4MC, X3 Join Date: Jul 2015 Location: Austin, TX iTrader: (0)	Raised the car 1/2 an inch and got an alignment yesterday. Along with the other changes, I feel this is a much better starting spot to tune the car to my driving style. Front Camber: -2.3 Front Caster: 8 Front toe: .04 Rear Camber: -1.7 Rear Toe: .21 I'll drive it on the street for a bit and do a few track days before I make up my mind but so far it's better. Turn in is crisp while high speed stability inspires confidence. I think this is likely a better place to start from based on my own driving skills.
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05-13-2017, 07:20 AM	#14
inTgr8r Lieutenant General 2426 Rep 11,667 Posts Drives: M2 Comp Join Date: Mar 2006 Location: Toronto iTrader: (10)	Sounds good . Alignment is a funny thing, there is so much going on with dependencies on how the rest of the car is set up. I always like to tweek one thing at a time when I'm making changes. __________________ '21 M2C Hockenheim Silver '18 718 Cayman S Lava Orange (sold) '13 E92 M3 Santorini Blue (sold) '07 Z4 M Coupe Alpine White (sold)
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06-09-2017, 08:41 PM	#15
doane2u First Lieutenant 91 Rep 341 Posts Drives: 2012 135i M Sport E88 Join Date: Jan 2016 Location: Carmel, CA iTrader: (0)	I just posted about a similar feeling with my 2007 E85 3.0i which has about 70k miles on it. At about 70-75mph it starts feeling sort of wonky, like there is a slight looseness in the steering which is really unsettling. Tires have only about maybe 3k miles on them. I've never had an alignment and don't feel any problems are any other speeds. As far as I know the car is stock. Any thoughts?
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