Ah Crap. Now I have something else to do this winter while rebuilding the rear suspension

Thanks for the pics, the mod looks great by the way.

 

There has been a ton of work done by Tom on this site with the kart measuring deflection. If memory serves me right the main problem is the disconnect between the a pillar firewall plane and the b pillar back of the seats plane. There were a lot of solutions discussed to make it better but in my mind until those 2 planes do not move independently the car will flex. An X brace might help a little and have no clue what a camber brace would help a lot being feet away from the problem. The only solution I see is either a cage with some low door bars or angled ones or a back bone through the transmission tunnel connected to steel on the front and rear planes mentioned. Possibly if the X brace is used with an X roof brace and one at the front and rear plane you would at least stiffen up 4 of the 6 sides of the cockpit area. Welding and plating the frame joints could not hurt either. But most of this well beyond the scope of a street car to fix GM mistakes.

It might help in my mind to run the suspension as compliant as you can stand to use the chassis as less of a spring but that does not inspire confidence in a driver but a visible bending chassis does not either. I bought mine 10 years ago with the thought of making 350 hp and doing some chassis work to make it real good at carving up country roads. Once I got into it I could see the draw backs and started o look pointless to do easy things so for me it was tear it to pieces and start over or enjoy it for what it is. I sold off all the easy parts I got for it heads cam intake headers heim joint struts for the rear suspension sway bars all of it. I have found it is a good car for what it is made to do but has definite limits most more imagined than real.

My take on it at least and not looking for a debate but maybe an alternate viewpoint.

 

This is a problem that GM should have had after market solutions for or stop bulding this C4 How can it really be corrected ? Does the ZR1 have this problem?

 

 

if you fabricate (or know someone who does) you could fabricate a brace that runs low across the chassis points.

 

I was thinking about mocking one up out of something like pvc piping and then having someone fab it out of steel.

 

the bought ones used a single slot to locate but I used a 2 hole plate across the A arm uprights. I think you could slot the 2 holes and it could be dropped into place (after loosening the bolts) rather than having to take the whole A arm assembly apart (like I did).