Shimmy in high speed corners

sig11 · 09-27-2011, 03:22 PM

I first noticed this odd behavior at Mid-Ohio last month. At the Kink (back straight has a slight right hand kink) I started to feel the car make a slight shimmy but generally feel stable there and anywhere else on the track. It only felt really odd in the rain.

Lately I've started to notice it on right hand highway curves and it's got me worried. It's sort-of like the front wheels wobble in short bursts. Could it be the control arms?

I'm going to take a trip to the dealer and see what they say since I still have ~2,500 miles of my warranty left but I wondered if anyone else had experienced a similar problem that might help me diagnose it.

Suspension is stock aside from Hotchkis swaybars, whiteline rear endlinks, and SPL camber arms in back.

corbin09 · 09-27-2011, 03:25 PM

My car does this too. Especially over "somewhat" rough road. It almost feels like the wheels are loose on the car for a split second and then it goes away and comes back again. I guess you have to experience it. Do you think front endlinks would help? I thought it was just my alignment settings and then that my offset may have been too aggressive but now I am starting to think it is something else. Maybe bushings?

sig11 · 09-27-2011, 03:47 PM

Yup. Small bumps do seem to make it worse. I have had plenty of miles on the car where I didn't feel the issue so I dont think it is the offset of my wheels.

I actually forgot to mention that I believed it was a problem with the front endlinks as I had broken one just before mid-Ohio. (I ran without a front bar there) After replacing the endlink the problem remained.

kenchan · 09-27-2011, 10:20 PM

tramlining maybe? i would check bushing, alignment, and front struts.

cossie1600 · 09-27-2011, 10:41 PM

I would start with the alignment first. You might not have enough toe.

ChrisSlicks · 09-27-2011, 11:15 PM

I agree. Get it on an alignment rack, while it is up there check all the bushings for play. Dynamic toe is not a good thing.

cossie1600 · 09-27-2011, 11:51 PM

LF/LR toe a little off maybe

sig11 · 10-06-2011, 03:09 PM

Way bad front toe... all the bushings looked good and aside from the alignment they replaced an incorrectly sized nut that I had put on the front left ARB endlink.
toe: 1.7l -1.45r
camber: -1.6l 0.2r

I definitely still felt the problem on the way home. They think it's the tires but I'm not so sure. I'm going to throw the stock wheels/tires on and see how they feel. They have been buried in my storage shed outside for exactly a year now but there shouldn't be any serious issues with the rubber, right?

kenchan · 10-06-2011, 03:16 PM

yah, one year should not affect it. keep them in a cool, dry area away from sunlight when in storage. i usually keep my stack in the garage or basement, storage. for good tires i have them in those tirerack totes.

sig11 · 10-06-2011, 03:54 PM

Hopefully they're wrong and it isn't the $1500 tires.

They still have a lot of tread aside from where I needed more camber.

cossie1600 · 10-06-2011, 05:02 PM

wait a sec. what are the specs again? did i see 1.8 degree in toe?

sig11 · 10-06-2011, 05:35 PM

Yeah... that's what the alignment printout read as the initial front toe and camber...

cossie1600 · 10-06-2011, 06:34 PM

I think they might have been screwed up. How do you have position camber? I think they didn't take the correct reading before, what is it now?

sig11 · 10-07-2011, 09:37 AM

Final is all in spec.
camber: -.8
toe: .05 total .10

cossie1600 · 10-07-2011, 12:30 PM

front looks fine, maybe a little bit conservative with that much toe. what about your rear toe?

09-27-2011, 03:22 PM	#1 (permalink)
sig11 A True Z Fanatic Join Date: Jun 2009 Location: Detroit Posts: 1,294 Drives: 09 370Z Red Sport-MT Rep Power: 17	Shimmy in high speed corners I first noticed this odd behavior at Mid-Ohio last month. At the Kink (back straight has a slight right hand kink) I started to feel the car make a slight shimmy but generally feel stable there and anywhere else on the track. It only felt really odd in the rain. Lately I've started to notice it on right hand highway curves and it's got me worried. It's sort-of like the front wheels wobble in short bursts. Could it be the control arms? I'm going to take a trip to the dealer and see what they say since I still have ~2,500 miles of my warranty left but I wondered if anyone else had experienced a similar problem that might help me diagnose it. Suspension is stock aside from Hotchkis swaybars, whiteline rear endlinks, and SPL camber arms in back.

09-27-2011, 11:15 PM	#6 (permalink)
ChrisSlicks A True Z Fanatic Join Date: Mar 2009 Location: North East Posts: 6,203 Drives: 09 370Z Sport M6 Rep Power: 653	I agree. Get it on an alignment rack, while it is up there check all the bushings for play. Dynamic toe is not a good thing. __________________ Hotchkis ARB \| Stillen CAI \| Art Pipes \| Berk CBE \| Stillen AP Racing Brakes \| AE Performance Oil Cooler \| BC Racing ER Coilovers \| Doran Control Arms

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09-27-2011, 03:25 PM	#2 (permalink)
corbin09 Track Member Join Date: Jun 2009 Location: Dallas tx Posts: 665 Drives: 370z Rep Power: 279	My car does this too. Especially over "somewhat" rough road. It almost feels like the wheels are loose on the car for a split second and then it goes away and comes back again. I guess you have to experience it. Do you think front endlinks would help? I thought it was just my alignment settings and then that my offset may have been too aggressive but now I am starting to think it is something else. Maybe bushings?

09-27-2011, 03:47 PM	#3 (permalink)
sig11 A True Z Fanatic Join Date: Jun 2009 Location: Detroit Posts: 1,294 Drives: 09 370Z Red Sport-MT Rep Power: 17	Yup. Small bumps do seem to make it worse. I have had plenty of miles on the car where I didn't feel the issue so I dont think it is the offset of my wheels. I actually forgot to mention that I believed it was a problem with the front endlinks as I had broken one just before mid-Ohio. (I ran without a front bar there) After replacing the endlink the problem remained.

09-27-2011, 10:20 PM	#4 (permalink)
kenchan A True Z Fanatic Join Date: Aug 2009 Location: N/A Posts: 76,801 Drives: N/A Rep Power: 141520	tramlining maybe? i would check bushing, alignment, and front struts.

09-27-2011, 10:41 PM	#5 (permalink)
cossie1600 A True Z Fanatic Join Date: Jun 2009 Location: californee way Posts: 5,380 Drives: 370, Leaf Rep Power: 29	I would start with the alignment first. You might not have enough toe.

09-27-2011, 11:51 PM	#7 (permalink)
cossie1600 A True Z Fanatic Join Date: Jun 2009 Location: californee way Posts: 5,380 Drives: 370, Leaf Rep Power: 29	LF/LR toe a little off maybe

10-06-2011, 03:09 PM	#8 (permalink)
sig11 A True Z Fanatic Join Date: Jun 2009 Location: Detroit Posts: 1,294 Drives: 09 370Z Red Sport-MT Rep Power: 17	Way bad front toe... all the bushings looked good and aside from the alignment they replaced an incorrectly sized nut that I had put on the front left ARB endlink. toe: 1.7l -1.45r camber: -1.6l 0.2r I definitely still felt the problem on the way home. They think it's the tires but I'm not so sure. I'm going to throw the stock wheels/tires on and see how they feel. They have been buried in my storage shed outside for exactly a year now but there shouldn't be any serious issues with the rubber, right?

10-06-2011, 03:16 PM	#9 (permalink)
kenchan A True Z Fanatic Join Date: Aug 2009 Location: N/A Posts: 76,801 Drives: N/A Rep Power: 141520	yah, one year should not affect it. keep them in a cool, dry area away from sunlight when in storage. i usually keep my stack in the garage or basement, storage. for good tires i have them in those tirerack totes.

10-06-2011, 03:54 PM	#10 (permalink)
sig11 A True Z Fanatic Join Date: Jun 2009 Location: Detroit Posts: 1,294 Drives: 09 370Z Red Sport-MT Rep Power: 17	Hopefully they're wrong and it isn't the $1500 tires. They still have a lot of tread aside from where I needed more camber.

10-06-2011, 05:02 PM	#11 (permalink)
cossie1600 A True Z Fanatic Join Date: Jun 2009 Location: californee way Posts: 5,380 Drives: 370, Leaf Rep Power: 29	wait a sec. what are the specs again? did i see 1.8 degree in toe?

10-06-2011, 05:35 PM	#12 (permalink)
sig11 A True Z Fanatic Join Date: Jun 2009 Location: Detroit Posts: 1,294 Drives: 09 370Z Red Sport-MT Rep Power: 17	Yeah... that's what the alignment printout read as the initial front toe and camber...

10-06-2011, 06:34 PM	#13 (permalink)
cossie1600 A True Z Fanatic Join Date: Jun 2009 Location: californee way Posts: 5,380 Drives: 370, Leaf Rep Power: 29	I think they might have been screwed up. How do you have position camber? I think they didn't take the correct reading before, what is it now?

10-07-2011, 09:37 AM	#14 (permalink)
sig11 A True Z Fanatic Join Date: Jun 2009 Location: Detroit Posts: 1,294 Drives: 09 370Z Red Sport-MT Rep Power: 17	Final is all in spec. camber: -.8 toe: .05 total .10

10-07-2011, 12:30 PM	#15 (permalink)
cossie1600 A True Z Fanatic Join Date: Jun 2009 Location: californee way Posts: 5,380 Drives: 370, Leaf Rep Power: 29	front looks fine, maybe a little bit conservative with that much toe. what about your rear toe?