Rear-end wanders at speed Help please
 

Hello,

So I have 2014 Z with 18k miles. nismo shocks and swift springs and spl rear camber arms.

Alignment was all out of wack and got an alignment and its as follows:

http://i.imgur.com/ueqUKFtl.jpg?1


The rear in certain roads acts like it wants to change lanes with no input from the front. When wet the effects are way greater. To the point of not feeling safe at anything over 60mph.

in perfect smooth surfaces its fine but when the road crowns or has imperfections it causes the rear end to wander.

Im guessing it must be the toe/camber but cant really explain it.

Any help as to how to fix this would be greatly appreciated since this feeling is very very unpleasant.

I found this thread and seems to be the same symptoms.
Wandering, floating, queasy feeling at high speed - Nissan 350Z Forum, Nissan 370Z Tech Forums
his issue was fixed with an alignment which he did not post.

thanks for the help.

Have you look at some of the other standard stuff, tire ware and pressure?

What condition are the tires in and do they all match? Mismatched tires front and rear and/or heavily worn rear tires could cause this. The post-alignment numbers don't really look off to me.

Tires are worn but still above the wear bars. And yes all matching.

And yes even tire pressure as well.

I wish i could get someone to drive it and better explain it.

Thanks

well, if your tires were worn at the old geometry then you will need to get new tires and break the new tires in to your new setting.

if that still dont help get some koni's and tighten the dampers down.

Tire can cause this. I had funky warn fronts due to the shipping spacers being left on the front springs for 19k miles. I just got them replaced and the car is mucho better in the handling department.

I wish tires would fix this problem. If tires woudnt fix this im afraid i would probably go back to stock suspension which i know didnt have that issue.


Were what you mean funky the same symptoms im talking about?

Oh and i forgot to mention i also have 20mm spacers all around.

thanks

Sounds like your tires. Uneven wear, especially in the rear will cause this sensation. Get under the rear of your car and check the inner edge of your tires. I bet, at least the passenger rear inner edge will have visible wear. Just my two cents.

Yes, the fronts were worn uneven on the outside due to + camber. The trembling was terrible. I would hooks ruts and they would drag me ever where all over the road. Probably looked like I was texting or drunk.

there are plenty of people with lowered z's that dont have this issue, so try the tires, then the dampers. GL

Your initial Toe settings were pretty horrible, I am not clear if you were having the problem with the initial toe settings or on the final toe settings. Your front camber although not bad, could be a lot tighter than -1.3 and -1.8 on the final.

Toe settings will definitely make the car "dartier".

I would try 0 toe in the rear.
back some rear camber out to about -1.1
and get both front wheels to -1.8

Also: Rear sway setting?

Two things:
1: The rear end alignment needs to be squared with the front end. Sometimes the rear wheels can be aligned square with each other, but not square with the front. This can create "dog walking", which can give this feeling.
2: you may have a blown bushing on your lower control arms or elsewhere within the suspension unit that appears visually ok, but when load hits it, it shifts.

I know the exact feeling you're talking about and it's very scary.

his after shows 0.0 degrees thrust angle.

One other thing could be (I know this sounds dumb)...you didn't tighten down the lug nuts 100%