mix and match suspension

I would be warry unless you know exact spring rates and you can do some dynamic model engineering.

I took an entire engineering course concerning Spring --Mass--Damper Systems (basically what a car suspension system is) and it is a very fine combination of mass (car weight) damping (shock viscosity) and spring rate (springs) to get optimal suspension response.

I **hope** that coilover companies take this into account, but i bet most of them do not and simply throw springs and shocks together..

the spring rates i know i want right around a 560 lbs/in to a 590lbs/in spring rate instead of the 670lbs/in that comes on the type flex's. And so long as the diameter of the spring is correct fitment shouldnt be a problem. i am just trying to ensure that the damper and tube will not be adversely effected by the change in springs or if anyone has done this and thier thoughts on it.

Have you tried contacting TEIN? I bet they have a range of springs to choose from.

The springs on the teins are wrapped around the coilovers front and rear correct? Any aftermarket springs for the z, the rear springs will be separate than the shock.

the front springs were around the coilovers while the rear were seperate until the mount was installed. i would need to see how the top of the front mount was installed on the piston of the coilover but i dont think it should be a problem. i emailed TEIN yesterday and havent gotten an email back yet.

I see the reason why you want to change, those spring rates on the Tein are quite high. Your ride is probably supremely harsh at anything below very spritied driving on a good piece of road.

I know that you won't want to hear it but best bet would be to ditch the Tein's and settle on some Koni shocks with some softer (than the Tein) linear or progressive springs.

Good luck

I agree with the teins as I have the flex series myself. It is a very harsh ride until you get used to it. After that it is not too bad. But if there is a better setup out there in the future with electronic dampening control then I will be switching over when it becomes available.

I doubt you will be hearing back from Tein with an offer of different springs you can buy to replace the ones on the stock type flex. Even though you can get softer springs like the ones sold only in Japan, they really don't seem to care too much about the US. Maybe it is just me but I didn't have a good experience talking with a phone rep in regards of what to use to clean my suspension to eliminate a squeaking noise.

Still no reply from TEIN. Although i did find the spring rate i wanted. now its just a matter of comparing vehicle wieghts and getting the physical size of the spring to ensure a proper fitment. It turns out that the spring rate for the type RE or RA coilovers for the R34(skyline) has the spring rate im looking for so i may see about getting a set of those shipped over.

Ok, sorry about the length of time between the last post but heres a bit of information for the FLEX owners out there. I talked with TEIN USA and you can use different spring rates with the coilovers.
The FLEX system has a range of +/- 2kg before needing revalving. if you are not up for revalving your coilovers then 2kg softer would bring you to a spring rate of 559lbs/in which is exactly what i am looking for. The springs are available for order from TEIN for $50.00 per straight spring and $65.00 for the tapered spring.
if anyone still has the flex's off and can get me the inside diameter of the springs it would be helpful, if not i will have to wait till i take mine off and measure them before i order the set.