I read that it is really your own prefereance when mix n matching springs. I have the Tein-S tech on my Z and I wanted to lower the rear a bit. Would using the Eibach Sport Lines in the rear completely mess with the balance of the car? I'm not going to pretend like I know alot about spring rates but here they are Tein's F(386lb) R (402lb): Eibach Sport Lines F: 239/400 R: 257/435 Any help would be greatly appreciated or even anyone who has tried this. Thank you

 

I was wondering about this as well... If you want a little more drop in the rear, you could try the sprig mount mod...

 

Best thing, get coilovers. $1000 for BC's and your done. Then sell your drop springs to cut the cost some.

If you hell bent on dropping the rear a little more, just shave the spring mount.

 

buying 2 set of springs ... might as well go for coilovers. =]

 

I see what you are saying about the coil-overs but I already have the Tein springs so $200 is looking alot better than $1,000, still I do see what you are saying about the coil-overs. I thought about the spring mount mod but I thought I read about bad stories of people who had side-effects latter from doing the mod. Anyone who has done the spring mount mod with some miles on it?

 

Whoops.

 

Stop being cheap and get the coilovers. I purchased the TEIN Super Racing Coilovers and even though they are pricey as hell, I can adjust the settings of my car's suspension for all conditions. I'm a TEIN enthusiast and I would recommend them for everyone but 'to each his own'.

 

A track orented setup with 896lbs spring rates and no MSV,....uh I don't see Tein blessing them with the "light" damping settings that could remotely be considered for "all condition's" if those condition's cover typical american road condition's. I have Ohlins, so I'm no stranger to what good construction and valving does. And I have nothing against Tein. I would love to see shock dyno's on the 350Z Flex, Monoflex and SRC to add to the collection of shock dyno's I already have.

 

Easy answer is to simply modify your rear oem upper spring mounts (cut material off them to make them shorter in height) to get the additional rear drop your after. Free and no worries about rear spring rate and you'll be sticking with a linear rear spring. Honestly though, 402lbs to 435lbs is a non issue.

What year is your Z?

 

Thank you for answering my question. I primarily wanted to know if the spring rate change would cause an unbalance ride. I have a 2006 GT which is why I got the Tein S-tech because I heard that they work great with the 2006's dampening. I considered the spring mount mod but I just don't know if that will affect my handling negatively since I have herd stories going both ways.

 

If your set on lowering the rear .5" you will have less negative effects with the spring mount mod where you keep the linear S-tech springs. The Sportline rear springs have a 178lbs difference between initial and peak rates. This impacts at the limit behavior and diminishes turn in and transient response. Compromises the Tein rear springs don't do.

I've tested a lot of spring rate combo's and I was the person that came up with the spring mount mod. I can't say that I ever used the mod to lower the rear vs the front as much as your talking about. But in every instance the mod itself had not adverse effects.


Having tested the following rate combo's

375/375 on Koni sports (Tokico D-spec springs w/.5" spacer above rear spring mount)
358/375 on Koni sports and oem shocks
358/427 on Koni sports (rear spring mount mod and 3/16 spacer back fill)
370/392 on Ohlins PCV (testing 70mm to 65mm adaptor on the front springs)
370/425 on Bilstein Pss9
370/427 on Bilstein Pss9 (rear spring mount mod)
448/342 on koni sports
448/427 on Koni sports and Truechoice Phase IV (rear spring mount mod)
560/427 on Koni sports and Truechoice Phase IV and revalved Bilstein Pss9 (rear spring mount mod)
560/450 on revalve Bilstein Pss9 (linear rear spring delete mod)
560/500 on Koni sports and revalved Bilstein Pss9
650/427 on Truechoice Phase IV (rear spring mount mod)
560/392 on Ohlins PCV (current setup)

 

I have been reading your thread and really am considering it and am just hesitant because I have stock struts so I was wondering if this mod had worked on stock struts.