Rear coilover adjustment very different side to side
 

So I thought I was going to finish this install up tonight, clearly not.

The front ride height is set and even between both sides.

With both rear coil perches adjusted the same, the drivers side is an 1 3/8" higher than the passenger.

Modifications I have made along with the coilovers:
Z1 front upper arms
Voodoo 13 solid rear subframe bushings, all bushings verified to be installed correctly, it is not a case where one side is higher up etc.
Voodoo 13 traction arms
Z1 rear camber arms

Things I have tried so far:
Disconnecting the sway bar
Removing both shocks
Swapping the coil springs and perch/collar from side to side

The only thing I can think of is maybe when I tightened back down the upper arm and lower spring bucket to subframe bolts I didn't do booth sides with the same droop so I might be getting some bushing bind?

http://www.the370z.com/members/sirni...-34-04-pm.jpeg
Passenger side coil assembly

http://www.the370z.com/members/sirni...-34-26-pm.jpeg
Passenger side wheel to fender measurement @ 3 1/4"

http://www.the370z.com/members/sirni...-34-55-pm.jpeg
Drivers side coil assembly (when I was trying to even out the gap)

http://www.the370z.com/members/sirni...-35-22-pm.jpeg
Drivers side wheel to fender measurement # 3 1/2"

I can understand 1/4" to 1/2" difference side to side to achieve same height but not over an inch :confused:

Over an inch difference sounds like alot

What coilovers are these?
Do they have threaded shock bodies in the rear?

Try doing it with a FULL tank of gas.

This issue you're seeing is that the gas tank saddle design lends itself to uneven gas levels at below half to quarter tank

And so with sloshing around one side of the tank will hold more fuel than the other when its gets to a lower level.

I went around this myself :facepalm: and so I remember if I need to make any adjustments to the ride height? it's done on a flat level surface with a full tank of gas.

I hope that makes sense :ugh2:

These are Fortune Auto 500 series coilovers.

The car has 3/4 tank of fuel in it at the moment and it is on level ground. I’ll bring some more fuel to fill it up and try loosening then re-tightening the upper control arms to even out any bushing bind.

Are they set to the same height on both sides? The pics look like they differ. I can tell you from doing around 10 sets of coilovers on the Z the front right (battery side) and Rear left are the "lower/heavier" corners. They are approximately 1/8 to 1/4 inch difference.

THe difference you have is not right in anyway.

Here are my questions.
1. Is the preload set to the exact same amount? (should be set at around 1/4 to 3/8 inch).
2. Are these used? Are the struts in perfect working order and are not blown?
3. Are the spring the same length? Manufacturer may have varied spring heights and maybe messed up here.
4. Do you have any excess weight on the rear of the car. I.e. subs etc.
I have found that every 50 pounds or so lowers the rear approximately an 1/8-1/4 of an inch depending on the spring rate type (8k is typical for rear).

I'll go by the car shortly and get some more pictures of how everything sits with the rear coil perches adjusted at the same height.

Sorry for the rotated pics, uploaded them from my phone.

http://www.the370z.com/members/sirni...33eb52c32.jpeg

http://www.the370z.com/members/sirni...46dbc4fa7.jpeg

http://www.the370z.com/members/sirni...e8b0695a5.jpeg

http://www.the370z.com/members/sirni...049a750b5.jpeg

Confirmed all subframe bushings are installed in proper orientation and are flush with chassis

Car is 2 dots away from full (man I hate that fuel gauge)

With both spring perches set to the exact same height I get the below measurements

http://www.the370z.com/members/sirni...e91ffc1e2.jpeg
Passenger side without shock

http://www.the370z.com/members/sirni...72c114df8.jpeg
Drivers side without shock

is the spring seat on the bottom seated right? The difference is too high

Yep i made sure to double check that too, i had a friend lower the car slowly while i watched the springs.

So then it's the perch you adjusted. You should be able to see where it was or match the side you like for height

Are these gas charged coil-overs?

Also when doing the rear. Check the front measurement to see if it moved.

VolkZ, it's not the perch that's the problem. I can swap the spring/perch assemblies and the result is still the same

Rusty, they are gas charged. The rear is OEM style where the spring and shock are separate.

It's been shitty weather here this week so I haven't gotten a chance to put the rear shocks back in, loosen and retighten all the bolts and go pot hole hunting to settle the suspension.

Time to trade her in then...

No idea man, trying to diagnose over the comp is pretty tough. I hope you figure it out.

:icon18: yeah remote troubleshooting is rough

I'll figure it out eventually I guess and I'll be sure to report back when I do.

Can you check the gas pressure in each shock?

No but since they are oem style coilovers I have left the springs in place and removed the shocks, same height difference so it's not shock related either unfortunately.

Ok... that eliminates if it might have been a gas pressure difference. Check to see if there are numbers on the springs. They should match.

It looks like some of the issue was the area I was working on isn't as level as my friend believed it to be.

That being said there is still about 3/4" difference in the adjustment between the left and right rear.

http://www.the370z.com/members/sirni...7607963588.jpg

These use the bottom rubber mount underneath the spring, correct? Make sure the spring is seated properly in that rubber mount. If it's rotated in the wrong position, it won't sit in the pre-molded slot. I did this initially in my install. Also make sure the top rubber cone mount is sitting the way it should be and is seated properly.

It's possible you have a bit of weight jacking going on from a improper cross weight.

Try adjusting the opposite side front perch and see if this balances it out any better. Before doing any more adjustments though. Have a friend measure the heights with you in the car. Then adjust the heights. This really need to be done on the flattest road you can find, if not the accuracy will always be off.

I did make sure all was seated properly.

I have it adjusted as good as it is going to get. There is only about a 1/2" difference between the coil spring height between the 2 sides.

This is definitely what appeared to be my issue and I did have to readjust the front once everything started to make sense. The place I was using has been used for at least 4 (The FD, a BRZ, S550 and my old NB) other cars suspension install that I can think of. All of which never ran into the issue I was having.

Still haven't gotten it aligned, my brother used to work for the Ford dealer so, he's pulling a few strings to be able to align it for me next saturday.

In the case of weight jacking to fix cross weight, you will most likely need to make asb endlink adjustments or you may start to get some rattling and steering problems.

You mean swaybar end links?

Any time you adjust ride height. You should have the sway bars disconnected.

asb =anti sway bar.

simply disconnecting them is not enough. they need to be re adjusted in order to set it back to zero load and fixing the position.

yeah the sways were disconnected when I was doing all this.

As far as adjusting them, they are stock at the moment. Next step is new tires and Hotchkis sways. Not sure I'll NEED the SPL adjustable endlinks (I understand their use etc, to spite this thread I'm not new to all this lol), sure do want them though.

See asb. thinking abs. :icon14: Didn't mention about needing adjusting afterwards. :icon14:

Adjustable endlinks are more so needed for adjustable ride height than they are for the actual sway bars. Without them you can have binding and unwanted asb preload.

Can you talk more about how the sways and links adjust the ride height? wouldn't it be ideal to have them both set equally on each side?

They don't adjust ride height, they adjust asb pre-load. In the case of adjustable ride height and corner balancing, the actual lengths between one corner and the opposing may not be equal, as such the length of the endlink needs to be modified accordingly to zero out preload on the sway bar. Having a endlink with a fixed length limits your ability to reduce asb preload in the situations where you have to adjust ride height.

As much as 5mm of height indifference corner to corner is enough to make a significant amount of preload on the sway bar. on average you can have up to 10mm of height difference depending on the driver weight. This is enough to put a lot of bind in the axle and start cause worn out endlinks and subsequent "noises". It will also impact steering linearity and weight jacking through a corner depending on which side is preloaded more.