has anyone ever done this my friend says its possible and i can imagine that it would probably lower the back of the car more b/c the g is higher and it lowers the g more, so has anyone ever done this or seen it done and does it make a difference and can the springs be put on our stock struts and in the back little plate thing sorry dont know what its called

 

Here's what it means

They will lower your Z

.7/.4 S-tech
.1/+.2 H-tech

They feature rear spring rates that are weaker then your oem spring rates by a rather large margin. This will reslut in a transfer of roll stiffness to the front fo the car. This is a method that tuners use to INCREASE understeer.

Tein H-tech G35 coupe & sedan(fronts are progressive, rears are linear)
324/260 F+ 5% R-22%
Transfers +27% roll stiffness to front

Tein S-tech G35 coupe & sedan (fronts are progressive, rears are linear)
358/274 R+14% R-18%
Transfers +32% roll stiffness to front

 

I have to ask, why are your needs not met with any of the current Z aftermarket lowering springs?

 

well first my friend has them for free lol so not a bad idea and second of all im not sure if getting the tanabes which i would rather do b/c from what i hear they actually for springs make the car handle better and feel better but they drop seems like alot and i dont want to be tucking tire and rubbing, if anybody has had any experience with the tanabes and 19s with a 295 on the back plz let me see a pic and your opinion on them