Here's info I pulled from the sticky'd spring thread:

NOTE!: Any aftermarket 350Z spring will lower a coupe a additional ½” over and beyond the published drop amount for the 350Z.

Oem linear springs
G35 coupes 2005/2006 with oem 19’s only. 350Z 2004.5 to 2008 (revised suspension) Front:314 Rear:427

Tein S-tech 350z
SKP26-AUB00(fronts are progressive, rears are linear) .7”/.6” drop on 350Z G35 drops will be higher Spring rates in LBS 386/402 (estimated front intial rate is 327lbs)

Tein S-tech G35
SKP30-AUB00(fronts are progressive, rears are linear) coupe drop 1.2"/.9" sedan drop 2"/1.3"
Spring rates in LBS 358/274 (final rates only, softer intial front progressive rate unknown)


SO, I need some expertise here, if my OEM rear LINEAR springs are 427 lbs (I'm guessing this is the amount of weight needed to compress the spring?-pls correct me) and the rear LINEAR Stech g35 springs are 274, does that make them much softer? I'm going for a slightly stiffer than OEM ride quality. Answers I get from this will help me decide which springs to get. Thx in advance.

PS if u have 350z s techs pls let me know how they worked for u

 

Anybody

 

I have a set of Tanabe NF210 springs on my coupe they dropped my coupe 1 inch in the front and .6 inches in the rear. I'm using the factory struts and shocks since they only had 30,000 miles on them when I installed the springs. The ride is a little firmer than stock and the drop is mild but noticeable and my car handles extremely well.

 

The rate you are using simply means how many pounds of force it takes to compress the spring one inch. So yes the 274 lbs/in would be softer than the OEM if both are linear.

 

I've been using Tein 350Z H-Techs for 6 years at least, the ride is perfect even when I was using OE shocks! The S-Techs will lower you about 1/2" lower than what I'm running. You will need a complete camber kit front and rear, figure that into the cost of lowering your ride! Check our Marketplace under vendor suspension for the kit. SPL offers the most adjustment to bring your alignment back to OE specs!
Gary

 

Very aware of alignment kit. Can someone tell me about increasing the damping on adjustable sport koni rear shocks when switching from OEM springs to the 350z stechs which are a slightly softer ride

 

You won't notice much with g s techs besides the drop.

 

Goin for 350z s techs cus they're closer to the stiffness of OEM