I have installed a set of RS*R springs on a 2004.5 350Z, but still using the stock shocks. At this time I was lookig for some drop and wanted to stay close to the stock spring rate, because I drive a lot on city streets. I believe the stock springs rates are 314 lbs FR and 427 lbs RR for 2004.5. The RS*R rates are 345 lbs FR and 417 lbs RR. I have the stock 17 inch wheels, but plan to upgrade to 18 inch and wider at a later time. My car has 42,000 miles on it. I am experiencing more bounce with the RS*R springs. Is it becasue the stock shocks are compressed with the .6 inch drop? I was thinking about upgrading the shocks to Koni Yellows in the future, but was hoping to get buy for a while on the stock shocks.

 

At 42k miles you stock shock are well beyond half used up. When you lower a car on stock spring the shock wear out even faster. Your ride will just get worse and worse, stock shocks don't last long on lowered cars.

 

i have 58k on my car, put eibach sportlines on at 45k, and everything is still fine, but i am setting aside money for new shocks in the near future.

 

shocks going out is like putting a frog in cold water and turning on the stove.. it happens so slowly, you cant tell.. ( frog doesnt jump out. dies)
same w your suspension bushings... you only think your set up is fine.. until you repair it and its a million times better.
Speaking from the exact same experience.

 

Oh so true, and a great way of saying it.

 

its funny, going to coilovers was nothing compared to the difference installing whitelines all over the front made.

 

OK, so maybe I just didn't notice the wornj out stock shocks on the stock springs as much as I'm experiencing it with the new RS*R springs. The bounce or stiffness is much more now. I wouldn't think just the Front spring rate increase from 314 lbs to 345 lbs would make this much difference. So I guess it can be the shocks. I assume Koni Yellow adjustables will work with springs that are lower than stock springs. I was actually looking for a similar ride, just lower.

 

that clarifies your question alot.
Lowering springs are stiffer.
Some are progressive.. and offer a softer overall ride but spool up to higher rate on the bumps. (Eibach etc)
cheaper ones wont have that design..
the only way to lower and have the same spriong rate and damping rate is to keep the overall spring height the same and just thread it donw farther.. and the only way you do that is with coilovers.

Youre fine for now.. just save up a grand for some decent Stance coils in the future.

 

BMCCANN101 - So it is just the extra stiffness of the front springs and maybe the combination of the compressed stock shocks? Thanks for your response.

 

So progressive rate springs such as Eibach would be a better choice and I would not be experiencing the problem I have now? I think the Eibachs lower the car 1 inch.

 

Combination of both.