Topic: Will The Z0K alignment be okay on GMPP springs?

[AdamVIP]

I have the GMPP springs and shocks with all the Z0K bars.  I have the Z0K alignment specs but the way it reads that you have to remove the second perch makes me think its height critical.  Will the Z0K alignment be okay for the GMPP springs/shocks?  I have searched for a GM spec for this suspension and it appears they never released one.  I currently have the car set up to be dropped off tomorrow night to be aligned Monday at the dealer (only place that has the rear caster gauge, or at least says they have it). 

For more background this car is not a daily driver.  I mainly use it for car gatherings and twisty roads.

Advice?   

[Coupe0091]

I have the full z0k setup now on my coupes. 

We could meet up one day this weekend, or week and you can see how it low it is compared to yours.

To be honest, I think it sits maybe about .5 inches lower in front, and maybe .75 lower in back as compared to stock.

With that little difference between stock and zok, I would bet the alignment specs would work on yours.

Kevin

[Sol Asylum]

I could be wrong but usually alignments are done with the car at its normal ride height, or in other words weight on wheels.  So the change in ride height should be taken into account when they do the alignment.

Now if you had the alignment done and then decided to raise or lower the ride height that would change the alignment and you would have to have it redone.  If the ride height is where you want it then get the alignment done and enjoy.

[shabby]

It doesn't matter what springs/shocks or whatever else you have, you can put whatever alignment specs you want on it.

[Coupe0091]

Adam,

From the ground to center of wheel to the top of the wheel well opening / fender line (hood)

Front:  27.5
Rear:   28.25

How does yours measure out....

[AdamVIP]

Im at 28 at the front and 28.5 in the rear right now. 

Its been settling less than 24 hrs with only one drive so it may get lower.  The ride height is what it is. Im done with suspension parts aside from bushings in the future.  I just figured it would be worth asking because the Z0K alignment tsb specifically says to remove the perches prior to alignment which to me means that ride height is an important factor n the numbers GM calculated for the alignment.

[AdamVIP]

Hey kevin.  You gonna go to woodland hills tomorrow?  We can compare then.

[Coupe0091]

Sure, Ill go.  I dont think I have any work scheduled for tomorrow.

Kevin

[snaponbob]

Once everything is installed you can have any alignment you like. The "GMPP alignment" can be used with any spring/bar package. To but truthful, that alignment is actually rather conservative !!!! So basically, do what ever you like. BTW, when the front end is lowered you will gain even MORE caster as well a bit more negative camber at every corner. The IMPORTANT adjustment is "toe" as that will really chew up tires if not at zero for street driving, and lowering DOES cahnge toe at all for corners. If you do the GMPP alignment make sure you use zero toe. If you want more camber that will just be a matter of another alignment.

Enjoy.

[wspohn]

I measured my stock unmodified car and it shows 28 1/4" F and 28 3/4" R.  What do other people have for stock heights?

I will be fitting adjustable struts but hadn't really wanted to go much below stock ride height due to driveway and speedbump issues.

[Ben L]

Yes it will be OK.  More negative camber does not hurt anything or compromise street driving.  As long as you leave toe near zero you will have no tire wear issues.  I find the ZOK alignment a bit too conservative, and nearly all my driving in the GXP is on the street.

[AdamVIP]

I just got it back from the dealership.  It took them all day.  The tech didnt really know how to align the car and I think I was his learning experience.  He did find some loose bolts on my driver rear shock though.  Kudos to him for that.  I had them do a .1 toe.  After looking in the service manual the stock configuration is a .1 toe so I figure it wont affect tire wear too bad.  Here were my end specs:

FRONT LEFT                   FRONT RIGHT
Camber     -1.7              Camber      -1.6
Caster      7.4                Caster        7.5
Toe         .1                  Toe           .1

REAR LEFT                     REAR RIGHT
Camber       -1.5            Camber      -1.4
Caster      told its -4      Caster told its -4
Toe          .1                Toe  .1

[Ben L]

Not enough front negative camber for my tastes, but to each his own.  Enjoy it!

[AdamVIP]

Its still a street car.  I didn't want to get too aggressive and go through tires at an alarming rate.

[Ben L]

Its been said before and I'll say it again:  Negative camber does not eat tires.  Toe does.

[snaponbob]

Ben is correc

Its still a street car.  I didn't want to get too aggressive and go through tires at an alarming rate.

Ben is correct. I have had from 2.4 to 2.8 negative camber on the front of my Redline for over 2 years and 18,000 miles. With 21K on the OEM tires, I have flipped the tires and have about 30-40% tread still left. Just keep the f&r toe setting at ZERO.

[wspohn]

Its been said before and I'll say it again:  Negative camber does not eat tires.  Toe does.

Well yes, that's true as far as it goes, but normal wear will be uneven on a car with a lot of negative camber, and you'll wear out one side of the tire before the other.

If they don't wear out any FASTER that they would have at stock camber setting, who cares?  In many cases they may wear out a little quicker if you are riding up the sidewall all the time, but with moderate cambers it isn't usually a problem.