On my blue hill climb car i the rear suspension is currently that it is individualised and the rods are shortened 6mm and the subframe is solid mounted and i have larger rubber rebound buffers. This makes it sit nicely and corner predictably and without the rear letting go to soon or being too soft as long as the road is smooth. But if the road is bumpy and i am pushing it or if the rear lets go it turns into a very bouncy ride with the rear some times leaving the ground.

Not only does this look stupid but it is also not very predictable. Of possible solutions i have thought about:

fitting rear shocks
Shortening the rods further and increasing pressure
Fitting gas valves to know how much is in
Fitting larger solid rebound stops and pumping pressure up against them

What do you think?

Sounds like like shock absorbers would be the logical choice, as classic under-dampened spring behaviour​.

Stiffening the rear may make this behaviour worse, but it is probably easier to test before committing to the damper option.

Mal

Thank you for the reply. I think i will start by shortening the rods 3mm more and then see how it sits and drives.

I wouldn't shorten the rods any more,
try reducing the rebound stop thickness, this will give the suspension more chance to do its job,
measure how much EACH rear wheel drops down from normal ride height when jacking up the rear
wheels, I'm willing to bet that they wont be the same each side, I used std rebound stops with a
spacer behind it to reduce the amount of droop, but I had to have a different thickness on the other
side to get the wheels to have the same droop measurement, I put this down to production tolerances
between the subframe/radius arm shaft centres/radius arm casting thickness.
my trackday metro had the rear end let go when I had to brake mid corner due to a newbie in front of me,
I reduced the rebound stops enough just to give an extra 10mm droop from ride height, it made all the
difference.

thank you for the knowledgeable reply I will measure and check what you wrote.