Convertible + Coilovers = Shimmy
 

Anyone out there with coilovers on a convertible? after installing a set on my 91 vert, the car has a wicked shimmy over potholes and rough pavement. It doesn't feel the same as a coupe with coilovers. Is the chassis just not rigid enough? Did I install them upside down? Too stiff a spring rate?

Just curious for some insight from someone more knowledgeable on suspension.

IThe vert chassis is a bit of a wet noodle. I've had what I wouldn't call it a shimmy, but definitely cowl shake. Is this through the steering wheel? Did you get it aligned after the install? What coilovers? How stiff? How low?

It's not really through the steering wheel. If you can imagine an old school cell phone vibrating on a table.. and it kind of crab walks across the table.. that's what the vert feels like over rough pavement! It kind of vibrates and crab walks a little. Right now the car is stock height, Knight Sport coilovers, I think they are 8k front and rear.. No alignment yet and the car is in bad need of toe adjustment. The Knight Sports replaced a set of tein coilovers that were as stiff as an I-beam.. it was so bad that it was literally not drivable on anything except the smoothest of pavements.

Then yes, it is because of the chassis. Triangulated strut brace and roll bar helped a bit, but the car really needs some door bars.

My 91 Vert is lowered on Stance Pro Coils. At first it was riding awkward, but with some trial and error i feel like this thing is super solid on any surface. I get compliments all the time by passengers about how good it feels for being on coils. It for sure doesn't feel like a wet noodle, i have no problem throwing it into turns on a autox track.
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do you notice any difference with the top up verse down?

Dude are you kidding me?

A few degrees of toe can make a car undrivable. Get it aligned and then report back. Jeesh

ahh thank you wise master of toe.. I am fully aware. The car had an alignment on the teins, before which it was absolutely terrifying to drive on uneven pavement. It hasn't had an alignment yet on the knightsports until I am satisfied that I don't need to make any additional modifications to the suspension.