2010 370Z touring roadster w/sports pkg, convertible

Hotchkis 370z front sway bar
SPL PRO Front Upper Camber/Caster Arms
SPL PRO Front End Links Spherical
SPL Eccentric lockout kit


KW Variant 3 Coil-overs (don't have adjustable shock heights)
SPL TITANIUM Rear Mid Links (when set in middle it allows for another 3/4 inch drop)
SPL TITANIUM Rear Camber Arms

Swift Springs 65mm 7inch 9k (I need to go to a 6inch or 5 inch?)
Swift Helper Springs H65-070-008 (was told by KW this is needed to avoid the POPing issue so many appear to have with the midlinks, this is caused when the spring is not under load, the spring will shift, move, and is dangerous, the helper spring stays flat until it is needed but does add 2" of height.

I currently have the 7 inch spring, the 9k is perfect, stock is 7-8k, I have a convertible and wanted a slightly stiffer ride.

My issue is with the helper spring at 7 inch, my car is like a 4x4. With just the 7 inch spring the car is stock height with the midlink where spl states it should be. That said, do I go with a 5 inch spring to allow for the helper spring, or go with a 6 inch spring? It looks like so many have the popping noise issue and everyone is all over the place with their setups. Suggestions?

Actually the solution is simple, get thrust washers from Swift. Super cheap, they go between the spring and the mount and allow smooth rotation. Conpletely solved any popping

I just ordered my Midlinks and 7" Swift springs today. I should be installing my suspension next weekend. I hope. I am going with 12k fronts and 10k rears.

Love my SPL Parts

Does anyone know if the HKS Hipersport IV gt coilovers work with these midlinks. Having trouble understanding the 2.5" thing

No reason it shouldn't.

You need to purchase separate swift springs, 2.5" to install these though.
That said, if you want to buy a set, with the springs, give me a shout. I'll be taking mine off shortly

2.5 inch is the diameter of the springs you need in order to fit the SPL midlinks' "spring bucket"

I suspect that japanese coilovers are gonna be using a wider diameter spring than that

this is why everyone's recommending you get swift springs

while you're at it grab some thrust washers to eliminate the popping sound from springs compressing and rotating against the perch

I have an issue setting my droop to 1/2 in. My coilover shocks will not shorten any further. Anybody else have this issue? I am at about an in. at the moment.

It sounds like you are slamming because your spring is moving in the midlink cup, you need to install helper springs to prevent this from happening. See my other post with what part you need or call KW directly and they will provide you with what spring you need.

An old thread at this point, but here's my take on the subject and current setup:

2014 370Z Nismo, factory shocks at this point. Lot's of Track Days and a Daily Driver. why not, it's a drivers car after all. Lots of aftermarket stuff but this thread is about suspension.

Rear:
SPL Rear Camber, Traction and Mid-Links. Swift 6" 65mm, 12kg springs (with nylon and steel thrust washers on the springs).

Front:
Still Factory, but not for long.

My initial impression is 6" Swift springs are the right length. Whether you chose 10kg, 12kg, or 20kg, they are a snap to swap and only additional drive time will tell on the stiffer or softer rating. 7 inch springs are too long. I would only want to adjust the ride height lower a bit, otherwise the adjustment cups might catch on stuff the more you let them poke out the bottom of the mid-link arm. With the instructions included, I adjusted the cup at or near the upper limit. This gives me exactly a factory ride height using a swift 6" spring.

Shout out to the SPLParts.com folks and for the helpful people there. They gave me great advice and aided in the spring selection and I look forward to doing more business with them.

Hope this helps some of you on the fence about what to get. If you haven't done so, reach out to SPL and ask them detailed questions. I did, no regrets.

Digging this thread back up since i am in the process of researching some stuff to do on my rear suspension

It appears SPL has updated their mid-link so it comes with an "adjustable" top hat now. Should allow the spring to be seated better

Rear Adjustable Toe Midlinks for the 370Z and G37 | SPL Parts

https://cdn10.bigcommerce.com/s-xn4b...0.1280.jpg?c=2

I've emailed them about whether this can be purchased separately

I'm trying to map out how an air cup system will work in the rear, from StanceParts. Might need some machining

Yep, the top hat is adjustable. I needed to adjust mine so that the springs sit vertical and not arced in a funny way. Very handy to have.

The adjustable top hat is new. Not sure when it was created but if you order now, you'll be getting those

My set from 2016-ish did not have them.

SPL sold me the adjustable set for about $100 shipped. I bought them for a . . . project that i hope to work on shortly

Sorry to revive this, is there a way of doing this with the KW V3 height adjuster, and OEM bucket? I bought a set of Kw V3 but was missing the rear springs, so i bought some Swift race springs ID65 12kg/mm 7" but there are two things, there is some play at the top with the adjuster, and the diameter of the spring is a lot smaller than the OEM bucket. Any ideas would be appreciated

You could do it if you bought the SPL midlinks. If you are missing the KWV3 springs you may be able to contact Kamispeed to see if they can get you the parts that you need to complete your KWv3 suspension.