RubyRed40

Hello. The first time (this weekend) I drove the car without the targa top (1993 40th Ann. Edition)....I've noticed the car shimmy at certain speeds.... and when braking....(steering wheel turning CW to CCW about 1/2 inch displacement.
Perhaps anyone know where the weak areas of the structure of the car would be with the targa top removed?
With the targa top installed, the car moves smoothly.
Thank you!

ddahlgren

The entire chassis is a flexi-flyer as originally designed to be a T-top but upper management decided targa would be better but no more money or time for engineering allowed. Convertibles have a X brace and there are a bunch of ways to stiffen the chassis some. I would be certain some will chime in with their favorite.

drcook

If you are wanting to drive with the top off, I would recommend reading this thread

https://www.corvetteforum.com/forums...-bar-afsb.html

And look into getting one of the truss bars.

I don't drive with the top off, I have a camber brace, a harness brace that ties the hoop together at the upper seat belt bolts and have a convertible x-brace in the shed to install.

I think for your purposes, just to be able to drive with the top off, the targa brace would be the way to go

RubyRed40

Thank you for the info. I'm always learning and it's good to know the facts, even when the news is less than desired....(limited engineering).

RWDsmoke

Is this while normal street driving? If so, a little chassis flex is normal, shimmy and shake is not. You might not feel it with the top on but it sounds to me like a little play somewhere in the steering or suspension. Even with the top off a C4 has less chassis flex than many cars out there. I'm sure it did not shimmy and shake when new and it shouldn't now. If you are talking about racing that's a different story.

gerardvg

I have never really noticed any excessive looseness, best way to check is jack one corner of the car up with targa top removed. if you cannot open and close the doors easily there is a problem,
have never had a problem doing this on my 85.
GM built these C4s well with a little flex / give in mind , otherwise there would be many broken in half C4 photos out there.

Don't worry about it, just drive the thing, PS when on a plane don't look at the wings flexing you might have a nervous breakdown ...