DIY camber ajustment on base (Z51) C6
11-01-2013, 09:38 PM
#1
Racer
Thread Starter
DIY camber ajustment on base (Z51) C6
Hi all, I was hoping to have more washers on the upper control arms of my 2007 Z51 base C6 as I attempt my first DIY alignment mod, but only have 1 washer per bolt. That won't give me the amount of negative camber I want for better cornering on HPDE days. I'm on mediocre street tires, so my goal was a modest -1.6 front and -1.0 rear.
How can bring the bottom arm out a bit? I don't exactly understand what I'm seeing with that nut/washer combo on the lower control arm where it mounts to the frame. Is there a pic or video describing how it is done? I assume that is where a shop would do minor adjustments?
Oh yeah, I know I need to adjust toe after this, so I'm planning on it.
Also, I will likely eventually buy a Pfadt shim kit or a Hardbar kit, but am just messing around at this stage.
Any help would be appreciated!
Dan
How can bring the bottom arm out a bit? I don't exactly understand what I'm seeing with that nut/washer combo on the lower control arm where it mounts to the frame. Is there a pic or video describing how it is done? I assume that is where a shop would do minor adjustments?
Oh yeah, I know I need to adjust toe after this, so I'm planning on it.
Also, I will likely eventually buy a Pfadt shim kit or a Hardbar kit, but am just messing around at this stage.Any help would be appreciated!
Dan
11-01-2013, 10:17 PM
#2
Racer
Thread Starter
I just noticed they're called the lower eccentrics, and really need to be torqued to the factory specs to hold in place. Now, I just need to know what to do with them!
11-02-2013, 07:33 AM
#4
Racer
Thread Starter
After taking the washers out, do you guys put the wheel back on and loosen / adjust the lower arm while measuring the camber of the wheel -- or make an adjustment without the wheel, reassemble, and measure?
Last edited by DannyBoyC6; 11-02-2013 at 08:56 AM.
11-02-2013, 08:55 AM
#5
Racer
Thread Starter
Front Cam Bolt Torque Spec?
Edit: found the missing torque spec for the front lower control arm cam bolts in another thread. For future searches, they are the following:
FRONT SUSPENSION
Upper Control Arm Mounting Bolts 65 N·m 48 lb ft
Front & Rear Lower Control Arm Cam Bolt Nuts 125 lb ft (missing from my David Farmer Spec PDF for some reason)
REAR SUSPENSION
Upper Control Arm Mounting Bolts 110 N·m 81 lb ft
Lower Control Arm Cam Bolt Nut - Front 145 N·m 107 lb ft
Lower Control Arm Cam Bolt Nut - Rear 95 N·m 70 lb ft
FRONT SUSPENSION
Upper Control Arm Mounting Bolts 65 N·m 48 lb ft
Front & Rear Lower Control Arm Cam Bolt Nuts 125 lb ft (missing from my David Farmer Spec PDF for some reason)
REAR SUSPENSION
Upper Control Arm Mounting Bolts 110 N·m 81 lb ft
Lower Control Arm Cam Bolt Nut - Front 145 N·m 107 lb ft
Lower Control Arm Cam Bolt Nut - Rear 95 N·m 70 lb ft
Last edited by DannyBoyC6; 11-02-2013 at 09:28 AM. Reason: found answer to question
11-02-2013, 11:40 AM
#6
The wheel needs to be back on since the car needs to be resting naturally on the ground. Make sure to get the suspension settled.
You will need to adjust camber caster and toe if you are pulling washers, especially toe - that can change significantly and you will scrub your tires down to nothing immediately.
You will need to adjust camber caster and toe if you are pulling washers, especially toe - that can change significantly and you will scrub your tires down to nothing immediately.
11-02-2013, 02:07 PM
#7
Race Director
The wheel needs to be back on since the car needs to be resting naturally on the ground. Make sure to get the suspension settled.
You will need to adjust camber caster and toe if you are pulling washers, especially toe - that can change significantly and you will scrub your tires down to nothing immediately.
You will need to adjust camber caster and toe if you are pulling washers, especially toe - that can change significantly and you will scrub your tires down to nothing immediately.
Unless you have alignment plates that bolt to the hub. Expensive.
11-02-2013, 05:40 PM
#8
Racer
Thread Starter
So next question for those with knowledge of a base (Z51) C6:
I just did the rear camber (well, attempted it
) but there is no upper control arm adjustment, and only ONE lower cam bolt adjustment in the front of the lower control arm -- the back bolt of the LCA is just a standard bolt. 
Do I adjust the front cam bolt to get negative camber and not concern myself with the back bolt at all? It seems like that would go massively toe out on the back tires and yield some strange geometry.
I just did the rear camber (well, attempted it
) but there is no upper control arm adjustment, and only ONE lower cam bolt adjustment in the front of the lower control arm -- the back bolt of the LCA is just a standard bolt. Do I adjust the front cam bolt to get negative camber and not concern myself with the back bolt at all? It seems like that would go massively toe out on the back tires and yield some strange geometry.
11-02-2013, 06:07 PM
#9
Drifting
How are you measuring camber and caster?
On the rear there is only the one eccentric on the lower arm as you are only adjusting camber.
On the front there are two eccentrics which allow you to set caster as well as camber. Moving the forward eccentric out on the LCA pushes the spindle back (on the bottom) which reduces caster. Caster and camber are also changed with the washers on the UCA. You'll get more caster as the spindle tilts back on the top or forward on the bottom.
Washers on the top in front usually make up for difference is side-to-side measurement from center line as the sub-frames (F&R) can be (and often are) not centered. Sometimes the subframes can be moved but for now don't worry about this. It will become more important as you max the camber settings or you want symmetry when using camber adjustment plates.
You've discovered that loosening the bolt on an eccentric allows you to move the a-arm in and out -- out giving you more camber.
How much negitive camber can you get F & R?
Can you get to the amount you want equally on both sides?
If so, lock it down and check caster on the F. You find that adjusting camber and caster can be a compromise and you may not be able to achieve what you want.
Once you have set camber (and caster in F) set toe. In the R you'll also need to check thrust angle. In F you may need to adjust the steering wheel.
That's a quick overview. Others will chime in.
--Dan
On the rear there is only the one eccentric on the lower arm as you are only adjusting camber.
On the front there are two eccentrics which allow you to set caster as well as camber. Moving the forward eccentric out on the LCA pushes the spindle back (on the bottom) which reduces caster. Caster and camber are also changed with the washers on the UCA. You'll get more caster as the spindle tilts back on the top or forward on the bottom.
Washers on the top in front usually make up for difference is side-to-side measurement from center line as the sub-frames (F&R) can be (and often are) not centered. Sometimes the subframes can be moved but for now don't worry about this. It will become more important as you max the camber settings or you want symmetry when using camber adjustment plates.
You've discovered that loosening the bolt on an eccentric allows you to move the a-arm in and out -- out giving you more camber.
How much negitive camber can you get F & R?
Can you get to the amount you want equally on both sides?
If so, lock it down and check caster on the F. You find that adjusting camber and caster can be a compromise and you may not be able to achieve what you want.
Once you have set camber (and caster in F) set toe. In the R you'll also need to check thrust angle. In F you may need to adjust the steering wheel.
That's a quick overview. Others will chime in.
--Dan
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c5wolf (02-09-2019)
11-02-2013, 06:27 PM
#10
Racer
Thread Starter
How are you measuring camber and caster?
On the rear there is only the one eccentric on the lower arm as you are only adjusting camber.
On the front there are two eccentrics which allow you to set caster as well as camber. Moving the forward eccentric out on the LCA pushes the spindle back (on the bottom) which reduces caster. Caster and camber are also changed with the washers on the UCA. You'll get more caster as the spindle tilts back on the top or forward on the bottom.
Washers on the top in front usually make up for difference is side-to-side measurement from center line as the sub-frames (F&R) can be (and often are) not centered. Sometimes the subframes can be moved but for now don't worry about this. It will become more important as you max the camber settings or you want symmetry when using camber adjustment plates.
You've discovered that loosening the bolt on an eccentric allows you to move the a-arm in and out -- out giving you more camber.
How much negitive camber can you get F & R?
Can you get to the amount you want equally on both sides?
If so, lock it down and check caster on the F. You find that adjusting camber and caster can be a compromise and you may not be able to achieve what you want.
Once you have set camber (and caster in F) set toe. In the R you'll also need to check thrust angle. In F you may need to adjust the steering wheel.
That's a quick overview. Others will chime in.
--Dan
On the rear there is only the one eccentric on the lower arm as you are only adjusting camber.
On the front there are two eccentrics which allow you to set caster as well as camber. Moving the forward eccentric out on the LCA pushes the spindle back (on the bottom) which reduces caster. Caster and camber are also changed with the washers on the UCA. You'll get more caster as the spindle tilts back on the top or forward on the bottom.
Washers on the top in front usually make up for difference is side-to-side measurement from center line as the sub-frames (F&R) can be (and often are) not centered. Sometimes the subframes can be moved but for now don't worry about this. It will become more important as you max the camber settings or you want symmetry when using camber adjustment plates.
You've discovered that loosening the bolt on an eccentric allows you to move the a-arm in and out -- out giving you more camber.
How much negitive camber can you get F & R?
Can you get to the amount you want equally on both sides?
If so, lock it down and check caster on the F. You find that adjusting camber and caster can be a compromise and you may not be able to achieve what you want.
Once you have set camber (and caster in F) set toe. In the R you'll also need to check thrust angle. In F you may need to adjust the steering wheel.
That's a quick overview. Others will chime in.
--Dan
I'm measuring camber with a level and ruler as shown by David Farmer. I adjusted both LCA eccentric bolts equally to push the bottom out in the fronts just to get the camber I wanted. Super easy.
:I haven't gotten to the caster yet but plan to as soon as I get the back wheels figured out. I guess I'm hung up on the fact that only 1 eccentric bolt on an arm with 2 hinge bolts would seem to unevenly push / pull the bottom of the wheel.
I will move on with adjusting the 1 back eccentric bolt, and get the caster lined out and see if I'm worrying about nothing. Then, I'll adjust toe -- 0 or 1/16" out in the front and 1/16 in for the back.
Thanks again!
11-02-2013, 09:33 PM
#11
It unevenly pushes the arm, not the wheel. The left/right orientation of the knuckle/wheel is primarily controlled by the toe link.
There will be cross-talk between the camber and toe adjustment, but it is because you are moving the a-arm in and out in aggregate, not because it is "uneven".
There will be cross-talk between the camber and toe adjustment, but it is because you are moving the a-arm in and out in aggregate, not because it is "uneven".
11-03-2013, 10:11 AM
#12
Racer
Thread Starter
It unevenly pushes the arm, not the wheel. The left/right orientation of the knuckle/wheel is primarily controlled by the toe link.
There will be cross-talk between the camber and toe adjustment, but it is because you are moving the a-arm in and out in aggregate, not because it is "uneven".
There will be cross-talk between the camber and toe adjustment, but it is because you are moving the a-arm in and out in aggregate, not because it is "uneven".
