The bounce test works, it should not bounce, simple, you push it down, it should rise back up to normal ride height, if it bounces then either the shock is worn or if you have a mismatched spring/shock combo then it is under-damped. With the race springs, it is hard to do this check because the springs are so stiff. Need to replace the struts/shocks on my wife's Flex, this test is very obvious because the suspension is so soft and compliant, it bounces. Since you run a spring/shock vice coilover setup, I would just remove the shocks on both sides, a good shock will take some real effort to compress and extend. Check them both in an absolute sense as well as compare to each other. Again, even the stock Cobra Bilsteins take some force to compress and extend.
As far as the Cobra R spec Bilsteins, they are roughly equivalent to a MM's MM2 series race damper which with the H&R race springs will likely give you a slightly over-damped condition. Ran H&R race springs with MM2 series dampers for a while, running hard if you really worked the suspension the over damped condition really affected the handling, actually performs much better with the higher spring rate (at the wheel) that I run now with coil-overs. The important piece is matching spings with dampers, I think you will find the R spec Bilsteins with the race springs will not be a good performing match-up.
this is not a spring/shock versus coilover issue. This is a shock problem given the wheel/tire combo should work. I think you have a bad shock, when you hit it, very little damping occurs on compression and you are bottoming out on the tire.
JMHO...
For the record though, you were asking about QA-1 shocks... here is my story... the ones you link to though are smooth body, the only QA-1 coilover shocks for IRS that I am aware of are a fully threaded body... which you will see in the pictures... again, I don't think you need to go coilover to solve your problem... though my MM2 series dampers with higher spring wheel rates with coilovers than my H&R race springs I used to run, ride much better than the race springs...
http://www.svtperformance.com/forums/showthread.php?1071722-IRS-Coil-Over-Auto-X-and-Drag-setups
r/
Andy
As far as the Cobra R spec Bilsteins, they are roughly equivalent to a MM's MM2 series race damper which with the H&R race springs will likely give you a slightly over-damped condition. Ran H&R race springs with MM2 series dampers for a while, running hard if you really worked the suspension the over damped condition really affected the handling, actually performs much better with the higher spring rate (at the wheel) that I run now with coil-overs. The important piece is matching spings with dampers, I think you will find the R spec Bilsteins with the race springs will not be a good performing match-up.
this is not a spring/shock versus coilover issue. This is a shock problem given the wheel/tire combo should work. I think you have a bad shock, when you hit it, very little damping occurs on compression and you are bottoming out on the tire.
JMHO...
For the record though, you were asking about QA-1 shocks... here is my story... the ones you link to though are smooth body, the only QA-1 coilover shocks for IRS that I am aware of are a fully threaded body... which you will see in the pictures... again, I don't think you need to go coilover to solve your problem... though my MM2 series dampers with higher spring wheel rates with coilovers than my H&R race springs I used to run, ride much better than the race springs...
http://www.svtperformance.com/forums/showthread.php?1071722-IRS-Coil-Over-Auto-X-and-Drag-setups
r/
Andy