Reviving this dead thread, I already have coilovers, I wanted to know what are the typical sizes people get (Length and Width) for springs if I wanted to switch the ones that came with my coilovers with Swifts?

The only thing I know are the rate of the Swifts has to be 12k just like the regular coils, and I'm assuming the Swifts has to be 180mm or 7 inches because that is also the length of the regular coils. My dilemma however is the width, which I don't know what it is and the manufacturer hasn't responded to me about the width yet. I see most 370Z coilovers are 65mm or 2.5 inches. I am thinking it might be the same for my Annex Coilovers?

It depends on the coilovers. My Aragosta's were 65mm diameter. The length was 10in. on the front. You would need to measure the springs length when it is not compressed on the shock housing.

So I just got a set of PowerTrix ultra-light Track coilovers with 13K/11K Swift springs. Haven’t installed them yet, but feel lost as far as setting them up goes.

I think they are 62mm in diameter and I know they are 180mm in length (just over 7inches). So, if I screw this this up and get let's say 65mm in diameter or 60mm that obviously won't work. I only see those sizes on Swift's site and nothing that is exactly 62mm in diameters for coilovers

I'm on the same boat. I was just going to leave the settings that Annex has on the coilovers and slowly over time start playing around with them before upgrading to Swifts.

The Aragosta fronts might be 62-65 mm but the rears are DEFINITELY NOT. They're damn near 4-5 inches. That is why I had to replace the rears with Swifts (65mm ID, 6 inch length) in order to use the SPL Mid-links

Don't bother installing them.

Get the SPL FUCA and rear arms.

Have an alignment/suspension shop install them TOGETHER, so you can do one trip on the lift.

Then you can do one alignment instead of multiple

Talk to your alignment guy about what type of setup will best serve your driving habits.

Throw away all the noise about negative camber. If you're doing anything but driving in a straight line on a drag strip, some negative camber is good.

Caster is good.

Toe in is helpful but only in small doses, as it affects tire wear the most

Ride height depends on your situation. And your wheels

As for the coilover settings. Start in the middle, play with it from there

Is that normal for most 370Z coilovers to be shorter and wider in the rear? The HKS coilovers I almost got and I think the Fortune ones were shorter in the rear. These Annex Suspension coilovers are 180mm both front and back, 62mm or I think 2.44 inches diameter front and back. How easy was it to switch out the springs? Or did you have a shop do it?

Have you seen the rear suspension of the Z?

The factory design places the spring independent of the damper, in its own bucket on a suspension arm. The damper connects to the rear shock towers up top, and mount to a different point below. Google 370z rear suspension for pixs

Swapping out springs is easy, I think u can just disconnect the mid link and the springs comes right out. If you have a lift you don't even need to remove the wheels I THINK (don't quote me)

The OEM bucket for the springs is much bigger than the SPL midlinks, which is designed specifically for a 65m ID spring

This is why you get all the parts and slap it on together

I actually just went out to look under my car, I see what you're talking about. They basically look like a short handle frying pan and it's holding the spring....You sure that is easier to swap out than the front? Won't that spring come flying out killing someone when you loosen the mid links? Because it looks like it will. The fronts looks like they just pop right out along with the shocks and you don't have to worry about getting killed.

I was going to do the fronts myself but the rears looks sketchy

The only thing I can think of is maybe putting a jack underneath those OEM buckets to slowly release the pressure. Then it should easily come out?

Jack the rear of the Z up. Use jackstands. Remove the rear tires. Makes it easier to get at the bolt and nut on the knuckle. Put jack under where the spring is and apply some pressure. Remove nut and bolt from knuckle. Slowly release pressure from jack and allow mid link to lower. It only has to come down a few inches to release all spring tension. Paid attention to how the spring is seated in the top and bottom mounts. There is a relief in the rubber cushion that the end of the springs sit in. And the spring is out.

The top "mount" is a rubber cone, fwiw

Ahh thank you. I see online that it's basically a rubber cone at the top just like Option said. That actually does sound easier than the front which has those brackets that I'm pretty sure have ceased up. I'll probably have to pick up a breaker bar to get them loose.