ledhead96

Whenever I drive this car [90 RS], I can feel every crack in the road.

I swear I can feel every bump, pot hole, crack, whatever. The rougher the road, the more violent the ride. Its almost unbearable to drive this car anymore.

I just had the car inspected. I had them check all my struts/springs/shocks. Wheels were balanced. I also had them do an alignment. They couldn't find anything wrong with my suspension.

What could be causing this?

Do you think I could have a bad rear tire? I've also thought about replacing the shocks.

Any ideas would be much appreciated!

Z28Nut

Did the shop air up you tires? Too much pressure in the tires will make it ride harsher, as will a lower aspect ratio (sidewall height). Has the car always ridden harshly or is it just something that's happened recently?

ledhead96

Hi. Thanx for the reply.

Its been like this for a year. I had the Shocks changed last January when I first noticed this problem. It didn't help. I then parked the car for several months. This Fall, I started driving the car again.

They checked my tire pressure for me and they are at 35 psi now. They said it was a little low.

I'm starting to think it's my tires. They are going on 4 years old, but they have a lot of tread left

CheshireCat

35 psi is probably too much pressure for your 90 RS... Check the reccomended pressure specs listed on the edge of the drivers door. I know for fact that the reccomended pressure on my 94 Z28 is 30psi front, and 30psi rear. I sometimes inflate them a little more for highway driving, but I can tell the difference in the harshness of the ride.
Good luck...

ledhead96

If my shocks and springs are ok [the shop said they checked out ok], then does that rule out everything but my tires?


The tires were balanced.

Sam Strano

What passes for "ok" my a lot of standards is terrible. First off, the old "bounce" test is completely inadequate. That's when you push on the car and see how much it bounces. It should go down and come up and that would indicate a good shock. BUT, that was then...... Old shocks were hydraulic only, no gas charge pushing back. The addition of the gas pressure (between 120 adn 360 psi depending on the damper) changes things so that you don't actually see what's happening. In other words with the small force of a guy pushing down, there isn't a lot energy to be damped by the shock, and the gas pressure along could very well do it. But when you drive the the car there is a LOT more force going on, and gas pressure isn't meant to and can't damp those forces.

Also, it's important to realize that shocks are velocity sensitive and have valves and valving that work on piston speeds. 1 in/sec if VERY VERY VERY SLOW in the shock world and not even worth talking about because it's not real-world. A person just cannot more the shock fast enough to see it's true valving.

From what I see here, I'm 99% positive your shocks are junk. Maybe not failed junk, but were never good (quality and damping wise, as opposed to "broken") shocks in the first place. If there were some cheap parts store shock, I'd not like the either. They just never seem to work even close to right.

What you describe is a classic case of improper damping. You can see that because the more the springs/wheels move, the worse things get.