C7 alignmemt
08-10-2018, 10:30 PM
#1
Burning Brakes
Thread Starter
C7 alignmemt
Has anyone done an alignment on the C7? I got the front just fine but am having a lot of trouble with the rear. When I adjust 1 wheel, the values change on the other side that I had just adjusted. When I drive the car or lift the wheels off the ground and then set it back down, the values change wildly. Any advice? I have already tried bouncing the bumper up and down. That didn’t change the values more than a half a degree or so.
Last edited by Luke42_02; 08-10-2018 at 10:30 PM.
08-11-2018, 07:36 AM
#2
Drifting
every time I go to the track and then when I get back home I change alignment.
The rear wheels should be done first and with the rear toe arm eccentrics it is a PITA to get all the settings within spec. Camber, caster are first, and with the OEM toe arms, you will still have to go back and fiddle with camber/caster as you TRY to get toe and thrust set.
First, do you have the wheels setting on something that will slide really easy? Some suggestions are 2 plastic cutting boards at each wheel with something between them to make them slide easily (like soap). Some folks have used a bunch of shopping bags. The ultimate for DIY would be turnplates (the cheap ones are no better than plastic cutting boards). Otherwise you will always get repeatablility errors because of the grip of the tires to the pavement.
There are several other things that could cause non-repeatability. A new car is unlikely to suffer from bad suspension bushings or a bad hub bearing. The one thing that will cause you measuring problems is a bent wheel or wheel runout (wobble).
If you are using a digital level, which is as good as anything else, they are usually accurate to 0.1deg or so, within 10 deg of 0 or 90. When the readout gets close to 0 you will get a bunch of display "flashing" where the readout seems to change. Seems like any vibration like someone closing a door will disturb the readout. I think it may be how the signal is electronically "damped" or something like that.
I think they are accurate enough for car alignments. After all, racers still use toe plates and tape measures with great success. The other thing you see a lot is a smartCamber devices for camber. Really it is a digital level mounted on a frame that gives 3-point contact to the wheel rim.
The rear wheels should be done first and with the rear toe arm eccentrics it is a PITA to get all the settings within spec. Camber, caster are first, and with the OEM toe arms, you will still have to go back and fiddle with camber/caster as you TRY to get toe and thrust set.
First, do you have the wheels setting on something that will slide really easy? Some suggestions are 2 plastic cutting boards at each wheel with something between them to make them slide easily (like soap). Some folks have used a bunch of shopping bags. The ultimate for DIY would be turnplates (the cheap ones are no better than plastic cutting boards). Otherwise you will always get repeatablility errors because of the grip of the tires to the pavement.
There are several other things that could cause non-repeatability. A new car is unlikely to suffer from bad suspension bushings or a bad hub bearing. The one thing that will cause you measuring problems is a bent wheel or wheel runout (wobble).
If you are using a digital level, which is as good as anything else, they are usually accurate to 0.1deg or so, within 10 deg of 0 or 90. When the readout gets close to 0 you will get a bunch of display "flashing" where the readout seems to change. Seems like any vibration like someone closing a door will disturb the readout. I think it may be how the signal is electronically "damped" or something like that.
I think they are accurate enough for car alignments. After all, racers still use toe plates and tape measures with great success. The other thing you see a lot is a smartCamber devices for camber. Really it is a digital level mounted on a frame that gives 3-point contact to the wheel rim.
08-11-2018, 01:11 PM
#3
Burning Brakes
Thread Starter
Thanks! I used two cutting boards with grease on the fronts but did not think I needed them on the back. I bet that is the problem.
08-14-2018, 03:14 PM
#5
Burning Brakes
Thread Starter
Subie, when you are changing alignments several times per season it’s not economical to pay someone. You’re also at the mercy of someone else’s schedule when you need to make a change. Cars were aligned just fine for many decades before the advent of laser alignment. It’s not important to have greater accuracy than a tenth of a degree, the biggest reason for laser alignment machines is so that any idiot can do it (and do it faster) without having to do any math. Many race teams still use the old method as there is no laser alignment at the track.
Its a normal adjustment of the car, not even a repair. I’m the type of guy who’s going to learn how to do that type of thing.
Its a normal adjustment of the car, not even a repair. I’m the type of guy who’s going to learn how to do that type of thing.
Last edited by Luke42_02; 08-14-2018 at 03:17 PM.
08-15-2018, 07:59 AM
#6
Drifting
Subie, when you are changing alignments several times per season it’s not economical to pay someone. You’re also at the mercy of someone else’s schedule when you need to make a change. Cars were aligned just fine for many decades before the advent of laser alignment. It’s not important to have greater accuracy than a tenth of a degree, the biggest reason for laser alignment machines is so that any idiot can do it (and do it faster) without having to do any math. Many race teams still use the old method as there is no laser alignment at the track.
Its a normal adjustment of the car, not even a repair. I’m the type of guy who’s going to learn how to do that type of thing.
Its a normal adjustment of the car, not even a repair. I’m the type of guy who’s going to learn how to do that type of thing.