05-11-2015, 02:54 AM
|
#1
|
Registered User
Join Date: May 2013
Location: Oklahoma City
Posts: 856
|
After 4-wheel alignment, handling is very twitchy.
I've been meaning to post this question, but keep forgetting until now.
A few weeks ago I put on new rear tires and had a 4 wheel alignment done along with having much of the negative camber taken out of the rears for a more neutral tire-saving setting.
Ever since, the handling of the car has gone from smooth and linear to twitchy and unstable.
It's hard to describe, but when steering into curves or making quick maneuvers, instead of the rear of the car following the front smoothly, pushing out a bit, it suddenly "tucks in" and "grabs" throwing the balance off.
I was alerted to how bad it was when I had to make an emergency maneuver on the turnpike yesterday.
Some idiot in an SUV comes charging on from the on ramp. I'm in the middle lane and the blind ass keeps charging across the lanes right into the side of my car, so I have to swerve into the next lane to avoid a collision. It's something I've had to do before as I'm sure many of you have at one time or another. Sucks, but no big deal. You quickly move the car into the next lane. But with the new handling quirk, the rear tucks and grabs, and suddenly throws my car sideways at 65 mph! I try to keep calm and gently start counter-steering, but the car just flips the other way. I have to keep correcting back and forth until the chassis finally settles and corrects itself.
I'm not a panicky driver. The avoidance and corrections I made were very minor and done with a cool head.
I'm now very aware something is wrong here creating very unstable handling.
Any ideas why a simple alignment could so dramatically change the characteristics of the car? Or could it be the tires? (I sort of doubt it, but...)
__________________
"Remember, I'm pulling for ya! We're all in this together."
|
|
|
05-11-2015, 03:10 AM
|
#2
|
Yeast Rancher
Join Date: May 2014
Location: Englewood, FL
Posts: 95
|
Did you get a print out of the settings they used? Sounds like you could use a tad more rear tow in.
__________________
2001 Boxster S
2010 Nissan Xterra S
Always get the S
|
|
|
05-11-2015, 03:34 AM
|
#3
|
Registered User
Join Date: May 2013
Location: Oklahoma City
Posts: 856
|
Thanks for the reply!
I didn't, but I have never had such an issue, so I didn't think to ask for it.
It's hard to explain, but the rears had fairly extreme negative camber which quickly wore out rear tires. I had that "corrected" and they did a full alignment while at it. It's possible they got the toe settings off. Before all of this, it was as stable as a rock at any speed with any maneuver.
Now when steering the slightest bit off center at higher speeds, the car grabs so quickly and violently that it actually tries to slingshot itself in the opposite direction.
__________________
"Remember, I'm pulling for ya! We're all in this together."
|
|
|
05-11-2015, 03:45 AM
|
#4
|
Need For Speed
Join Date: Feb 2013
Location: Funville
Posts: 2,112
|
I pulled this from another thread. Maybe go back to the alignment shop and have them check the settings per the data sheet that Smallblock454 provided.
Quote:
Originally Posted by Smallblock454
Hi,
take a look at the sheet i've attached. There you'll see the wheel align values. As you are livning in the UK, please use the clumn RoW Series for orientation.
It seems that they didn't adjust the camber on the left side. Maybe because you can't adjust camber on most older MB cars. Also it takes a lot longer to adjust everything to specs.
Over here in germany it is very important to adjust wheel alignment very correct, because the car is sensible at high speeds.
Regards Markus
|
__________________
2003 Boxster S
| 987 Air Box | K&N Air Filter | 76mm Intake Pipe| 996 76mm TB | 997 Distribution T | Secondary Cat Delete Pipes | Borla Muffler | NHP 200 Cell Exhaust Headers |
|
|
|
05-11-2015, 04:14 AM
|
#5
|
Registered User
Join Date: Nov 2012
Location: SW Okla
Posts: 1,115
|
I have the exact situation going on right now with my Aero car. I had all 4 sway bar links replaced and a 4 wheel alignment done right before I went to Hallett last weekend.
The car drove fine Sat, but somewhere between Sat and Sunday it developed the same characteristics - twitchy and unstable (the exact words I used to describe how it was acting). The front end felt like it was floating above 75mph, and I had the same tuck/grab get me sideways in a corner where I've never had a problem before. (I was chasing a GT3 pretty hard through the corner at the time, but I'm sure that had nothing to do with it. )
The car tracks straight down the road, but the steering wheel is sitting at the 1:00 o'clock position.
I too didn't get a read-out.
Did you take your car to your normal place, or did you use the guys I go to - just for comparison? (Don't want to name names, because both places are normally flawless in their work)
I'm bringing my car back in next week to get looked over and I'll be back at Hallett on the 30th, so hopefully it'll get figured out.
Let us know what you find out.
__________________
I think I have a Porsche problem...
|
|
|
05-11-2015, 04:48 AM
|
#6
|
Registered User
Join Date: May 2013
Location: Oklahoma City
Posts: 856
|
Thank you for the readout Kram! I'll print that out and take it with me.
Interesting you're having the same character shift in your car after an alignment RedTele. I did take it to my usual place, and as you say, they're usually flawless in their work, but something went off here. I recall them saying they had trouble with the rear camber adjustment and couldn't quite get it to factory specs. I'm wondering now if they might have sacrificed toe settings in an attempt to get the camber in line. (honestly I don't know much about this stuff, just going off of what I've read and heard in my research)
__________________
"Remember, I'm pulling for ya! We're all in this together."
|
|
|
05-11-2015, 05:57 AM
|
#7
|
Registered User
Join Date: Sep 2013
Location: KRK, PL, EU
Posts: 255
|
Hey guys, great timing!
Just over a week ago (and was busy since), I got the car aligned. Around the city it feels fine, but when I took it to some nice twisty roads, I got scared. The car became, as you said, twitchy.
I was so concerned, last week I took it to another shop to check that everything was tightened down properly. It was.
Attached is the printout I got from them. Plus some translations so you don't have to learn Polish.
No I'm starting to think this is how the car is supposed to be. More direct. More raw. I like it!
__________________
Past: 944 NA white '86
Present: 986 black '98
Future: 959
|
|
|
05-11-2015, 09:05 AM
|
#8
|
Registered User
Join Date: May 2011
Location: Miami florida
Posts: 1,591
|
It could just be your tires. New tires are very squirmy because the tread blocks are very tall and the rubber is soft from the factory. After a few heat cycles, the tires firm up and handle better. when I got 4 new tires, my first ride out I thought I was on ice.
And by the way, wear on the inside rear tires is likely not from the negative camber in the rear. Its usually from too much toe.
__________________
Current car
2000 Boxster 2.7l red/black
Previous cars
1973 Opel Manta
1969(?) Fiat 850 Convertible
1979 Lancia Beta Coupe
1981 Alfa Romeo GTV 6
1985 Alfa Romeo Graduate
1985 Porsche 944
1989 Porsche 944
1981 Triumph TR7
1989 (?) Alfa Romeo Milano
1993 Saab 9000
Last edited by san rensho; 05-11-2015 at 09:07 AM.
|
|
|
05-11-2015, 10:10 AM
|
#9
|
Registered User
Join Date: Apr 2008
Location: Southern New jersey
Posts: 1,054
|
Doesn't Toe Out cause inside wear? There should always be some Toe In at the rear.
|
|
|
05-11-2015, 11:51 AM
|
#10
|
Certified Boxster Addict
Join Date: Nov 2010
Location: Los Angeles
Posts: 7,669
|
Could be the tires, but I'd guess that the tech messed up the rear toe alignment when he adjusted the rear camber. I'd take it back to the shop that did the alignment and have them check it. If its ok, then give the tires some miles to wear in and see if that helps.
__________________
1999 996 C2 - sold - bought back - sold for more
1997 Spec Boxster BSR #254
1979 911 SC
POC Licensed DE/TT Instructor
|
|
|
05-11-2015, 06:18 PM
|
#11
|
Registered User
Join Date: May 2013
Location: Oklahoma City
Posts: 856
|
Looks like a consensus is forming.
I'll ask the shop to recheck the alignment with factory specs, especially the rear toe. I put about 700 miles a week on the car so any improvements related to the break in of the tires should creep up in a fairly short time. New tires didn't affect the handling feel of my weekender Boxster, but I've never had to have an alignment done on that car. It's possible in this case that it's a combination of the two.
Thank you guys so much for the input. I think you're on the right track.
__________________
"Remember, I'm pulling for ya! We're all in this together."
|
|
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is On
|
|
|
All times are GMT -8. The time now is 09:29 AM.
| |