Hard, harsh ride! Want to install Illumina adj. Shocks/Structs from Victoria British Ltd. Any thoughts?

Those are well-regarded struts but I'd be curious about the rest of your suspension. Lots of things can contribute to a harsh ride such as tires (especially big rims with low profile tires), springs, bushings, etc. Also, keep in mind that what might seem harsh to you might be considered normal for a 240Z.

Another thing that you might not have even considered is that the padding in your seats may need replacing.

Speaking of struts, has anyone here used the Edelbrock IAS struts or shocks? I am not even sure iof there is an application for the Z cars, but supposedly they are anice setup, firm but comfortable over the bumps. IAS stands for Inertia Active System I beleive. It has to do with the valving design and mechanism.

What do you recommend for an otherwise stock car in terms of ride height and suspension?

Todd

It's been a while since I have posted here.

The struts that I have are KYB G-2. I am vary satisfied with the ride. It is firm but not harsh, I also am running

Euro stage l springs that I have cut to lower the car. They are not a progressive coil spring so cutting them doesn't change the stiffness. Just this past weekend we drove to the Coast and on some vary twisty back roads 260 miles and they are still working great. I have had this set up installed for about 4 years now and I wouldn't change a thing. On the hwy and normal driving the ride is great. I only bottom out on severe bumps but with the bump stops on all

four corners it's no problem at all.

Hope this helps.

Gary

Necropost of the day! This thread is over 7 years old...

They are not a progressive coil spring so cutting them doesn't change the stiffness.

It's a coil spring. If you cut a coil off, the spring constant (stiffness) will increase, no matter if it's progressive or linear.

k= (G*d^4) / (8*n*D^3)

k - spring stiffness

G - a constant dependent upon material used

d - wire diameter

n - number of "active" coils (this varies with the type of spring ends)

D - average coil diameter

Therefore, stiffness increases as you decrease the amount of coils, increase material rigidity, increase wire diameter, or decrease average coil diameter.

It's been a while since I have posted here.

Good to see you back, Gary.

It's a coil spring. If you cut a coil off, the spring constant (stiffness) will increase, no matter if it's progressive or linear.

k= (G*d^4) / (8*n*D^3)

k - spring stiffness

G - a constant dependent upon material used

d - wire diameter

n - number of "active" coils (this varies with the type of spring ends)

D - average coil diameter

Therefore, stiffness increases as you decrease the amount of coils, increase material rigidity, increase wire diameter, or decrease average coil diameter.

I'll agree in theory. But I have the same springs as Gary, and I also have used them on the same car both before and after cutting them down. The difference in stiffness was negligible. No difference in ride stiffness. I'm going to guess that while the spring rate may have increased, the preload decreased (due to the shorter free length). Appears to have been a wash.

Any experience on MSA KYB shocks? Im planning to replace my ORIGINAL shocks. Lousy shocks, only lasts 40 years...

KYB are fine. I've put a few sets in Z's for club members. You can buy them at most local shops. No need to ship from MSA.

Good to see you back, Gary.

I'll agree in theory. But I have the same springs as Gary, and I also have used them on the same car both before and after cutting them down. The difference in stiffness was negligible. No difference in ride stiffness. I'm going to guess that while the spring rate may have increased, the preload decreased (due to the shorter free length). Appears to have been a wash.

Preload? Stiffness doesn't depend on preload...

You can't rely on your "butt dyno" to say there was no difference. Unless you put the springs in a spring tester, you can't draw that conclusion. Depending on how much the springs are cut, the increase in stiffness may not be drastic but it will increase nonetheless.