Two months ago I purchased a set of Eibach Progressive springs and installed them on my 72 240Z. My goal was to lower the car about an inch, which the springs accomplished. I did not install new strut cartridges when replacing the springs however because the KYB struts had no more than 10K miles on them. My ride at this point is pretty awful, very bouncy. I'm wondering if this spring/strut combination is not compatible or if maybe the struts are shot or blown out. The car rode and handled fine before the new springs. Anybody have a similar experience and find a solution? I've read through the posts on springs and struts but did not find this specific problem. I'm tempted to replace the KYB's with Tokiko's but I don't want to drop $400 if that wont solve the problem.

This thread might be informative - http://www.classiczcars.com/forums/thread47896.html

FWIW, I have this spring/strut combo and I haven't experienced any bouncy ride. Your struts maybe worn out even though the miles are low. Bouncy means no shock dampening.

Cheers, Mike

A "bouncy" ride means you are very underdamped. However, I think you'll find that the Tokicos are a lot stiffer but definitely not bouncy when combined with Eibachs.

Edited November 27, 201212 yr by LeonV
Clarity

Randy,

What tire size (and wheel size) are you running? If you have very low profile tires and larger wheels, the combination of those with the stiffer struts may cause too harsh a ride. There is a huge difference in sidewall flex between 50 and 60 profile tires; manufacturer and model of tire has a large impact as well.

My ZX borders on bouncy. I don't get a REBOUND, indication of worn out shocks/struts, but I get a full bounce.

And I discovered I like it that way. It makes the ride SOFTER than with super-firm struts that transmit every bump right to your spinal column.

The new struts I ordered are still sitting in the garage.

Just wait. When you hit age 55-60 your taste in suspensions will change too.

KYB's documentation specifically states that their inserts are not to be used with lowering springs. My personal experiences (non-Z) when ignoring that advise was that the inserts were ineffective in very short order. I'd recommend new inserts designed as suitable for a lowered car.

Looks like some Tokiko's are in my future. I'm currently running Panasports and 215-65-16 inch Hankook tires. Thanks guys for weighing in.

Are you really running 215/65R16 tires? Those would be over 2 inches taller than stock.