More alignment woes
10-11-2016, 09:32 AM
#1
Burning Brakes
Thread Starter
More alignment woes
I went to confirm the track alignment as I didn't get a printout last time I was in. Tech said he cannot get the proper toe in the left rear, that the adjustment bolt is maxed out. He suspects something is bent on that side. We tried to bring the right rear camber down to be closer.
Prior to last track event the toe was fine. I have hit nothing with this car to my knowledge on or off track. I can't figure out how this could be the case.
I have a track event, coming up on Friday and am wondering what this will do to handling.
Left Front
Camber -2.1
Toe + .06
Right Front
Camber -2.1
Toe + .09
Total toe .15
Left Rear
Camber -1.2
Toe + .25
Right Rear
Camber -1.5
Toe + .02
Total toe +.27
Prior to last track event the toe was fine. I have hit nothing with this car to my knowledge on or off track. I can't figure out how this could be the case.
I have a track event, coming up on Friday and am wondering what this will do to handling.
Left Front
Camber -2.1
Toe + .06
Right Front
Camber -2.1
Toe + .09
Total toe .15
Left Rear
Camber -1.2
Toe + .25
Right Rear
Camber -1.5
Toe + .02
Total toe +.27
Last edited by RS4EVA; 10-11-2016 at 11:11 AM.
10-11-2016, 05:04 PM
#3
Supporting Vendor
Can you verify toe in or toe out for the front and rear? Each machine is different.
Camber is a semi big deal, but toe is first and foremost with your current camber numbers. What tires?
Camber is a semi big deal, but toe is first and foremost with your current camber numbers. What tires?
10-11-2016, 06:12 PM
#4
Burning Brakes
Thread Starter
10-11-2016, 07:05 PM
#6
Supporting Vendor
Toe out front and rear? It will be an evil evil handling car.
10-11-2016, 07:15 PM
#7
Tech Contributor
Member Since: Oct 1999
Location: Charlotte, NC (formerly Endicott, NY)
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GM specifies toe in as positive and the settings indicated in their FSM and in the Track Alignment Bulletin are specifed as such. The Track alignment suggests +.0005 of Toe In with a tolerance of plus or minus .2 degree of total toe. You are a shade out (.07 degrees) on the left side. You could compensate to some degree by adding more toe out on the right but the car would probably get twitchy.
The interesting thing is I have around -1.6 rear camber and the mechanic was still able to get toe in. Was rear caster set? It would have to be a hand notation on the machine's print out since the machine can't measure it.
As for a potential reason the cradle may have shifted a little. I know on my C6 there was about a tenth of an inch play around the pins that located the cradle or the rear control arm bushings have gone bad.
Bill
The interesting thing is I have around -1.6 rear camber and the mechanic was still able to get toe in. Was rear caster set? It would have to be a hand notation on the machine's print out since the machine can't measure it.
As for a potential reason the cradle may have shifted a little. I know on my C6 there was about a tenth of an inch play around the pins that located the cradle or the rear control arm bushings have gone bad.
Bill
Last edited by Bill Dearborn; 10-11-2016 at 07:18 PM.
10-11-2016, 07:21 PM
#8
Is this the same shop that aligned the last time where you ended up with high tire wear?
Has the trans ever been our of the car or any other reason to drop the rear cradle? There is some play side to side when the cradle is loose and I wonder if the tech is compromising toe to try and get more camber.
Also, did you remove any UCA washers?
Has the trans ever been our of the car or any other reason to drop the rear cradle? There is some play side to side when the cradle is loose and I wonder if the tech is compromising toe to try and get more camber.
Also, did you remove any UCA washers?
10-11-2016, 08:10 PM
#9
Drifting
Member Since: Feb 2015
Location: Syracuse-Central Square New York Winer of the all Corvette race WGI 8/23!
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Weve had issues getting rear toe where we want it if the eccentrics are in certain combinations. Usually causing us not to get as much rear camber as wanted. Before next season we are installing the aftermarket toe rods. BTW you cannot get rear toe in decent street levels when removing all the rear UCA washers we found. We have run rear toe out .05 at each wheel with rear caster between +1.0 to 1.4 with great success! Just had a customer run the same numbers with the same out come. These cars have progressive rear toe so you can start in the positive range. OP you must check rear caster or bad things could happen. The last new Z we checked had rear caster different from side to side and one side in the negative range, not good!
Bent control arms are possible. We are pretty sure we bent the left front upper on our Z06. Only slight but enough to get caster in range. Will change it out before the next track season for sure. No accidents or wheel hits so we suspect it was caused by attacking the apex rumbles, Watkins Glen has some monsters!
Bent control arms are possible. We are pretty sure we bent the left front upper on our Z06. Only slight but enough to get caster in range. Will change it out before the next track season for sure. No accidents or wheel hits so we suspect it was caused by attacking the apex rumbles, Watkins Glen has some monsters!
10-11-2016, 08:20 PM
#10
Burning Brakes
Thread Starter
@Maddog, Can you explain more about the different combinations for the eccentrics? That sounds similar to the issue the tech was having. Increasing rear camber led to toe out of spec. Only by decreasing camber did the toe come down slightly.
@gspeed, sounds like I was wrong about the direction but I thought he said toe out in rear.
@poor-sha this was done at my Chevy dealer.
@gspeed, sounds like I was wrong about the direction but I thought he said toe out in rear.
@poor-sha this was done at my Chevy dealer.
Last edited by RS4EVA; 10-11-2016 at 08:22 PM.
10-11-2016, 08:47 PM
#11
Drifting
Member Since: Feb 2015
Location: Syracuse-Central Square New York Winer of the all Corvette race WGI 8/23!
Posts: 1,858
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It is impossible to describe here but we found a sweet spot with the rear eccentrics. The sweet spot is much larger with the washers removed from
the UCA. But unfortunately they need to be reinstalled to get a proper street camber toe alignment. For this reason we are going with an aftermarket tie rod, leave the washers out for some big time camber! Less straight line tire to track friction may even equate to additional top end speed
To be done properly you MUST have the rear caster gauge attached to the spindle while adjusting. Your GM dealer should have one if not run!
the UCA. But unfortunately they need to be reinstalled to get a proper street camber toe alignment. For this reason we are going with an aftermarket tie rod, leave the washers out for some big time camber! Less straight line tire to track friction may even equate to additional top end speed
To be done properly you MUST have the rear caster gauge attached to the spindle while adjusting. Your GM dealer should have one if not run!
10-12-2016, 11:25 AM
#12
Burning Brakes
Thread Starter
It is impossible to describe here but we found a sweet spot with the rear eccentrics. The sweet spot is much larger with the washers removed from
the UCA. But unfortunately they need to be reinstalled to get a proper street camber toe alignment. For this reason we are going with an aftermarket tie rod, leave the washers out for some big time camber! Less straight line tire to track friction may even equate to additional top end speed
To be done properly you MUST have the rear caster gauge attached to the spindle while adjusting. Your GM dealer should have one if not run!
the UCA. But unfortunately they need to be reinstalled to get a proper street camber toe alignment. For this reason we are going with an aftermarket tie rod, leave the washers out for some big time camber! Less straight line tire to track friction may even equate to additional top end speed
To be done properly you MUST have the rear caster gauge attached to the spindle while adjusting. Your GM dealer should have one if not run!
Last edited by RS4EVA; 10-12-2016 at 11:25 AM.
10-12-2016, 09:43 PM
#13
Le Mans Master
Weve had issues getting rear toe where we want it if the eccentrics are in certain combinations. Usually causing us not to get as much rear camber as wanted. Before next season we are installing the aftermarket toe rods. BTW you cannot get rear toe in decent street levels when removing all the rear UCA washers we found. We have run rear toe out .05 at each wheel with rear caster between +1.0 to 1.4 with great success! Just had a customer run the same numbers with the same out come. These cars have progressive rear toe so you can start in the positive range. OP you must check rear caster or bad things could happen. The last new Z we checked had rear caster different from side to side and one side in the negative range, not good!
Bent control arms are possible. We are pretty sure we bent the left front upper on our Z06. Only slight but enough to get caster in range. Will change it out before the next track season for sure. No accidents or wheel hits so we suspect it was caused by attacking the apex rumbles, Watkins Glen has some monsters!
Bent control arms are possible. We are pretty sure we bent the left front upper on our Z06. Only slight but enough to get caster in range. Will change it out before the next track season for sure. No accidents or wheel hits so we suspect it was caused by attacking the apex rumbles, Watkins Glen has some monsters!
Jim