Originally Posted by
vafactor
It's likely that a major source of your double steering issue is too light of dampening in the side tubes. Most guys run at least 10,000 in the tubes these days (I think the blue cap CRC bottle is about 10,000). A few of the team drivers have been going as stiff as 50,000. I suggest that you try 20,000. Then, an easy way to tell if it's too thick is to run a few laps with the 20,000, pull over quickly and pop off one tube and run a few more laps with just one tube connected. You'll know right away if that simple and quick trackside change made the car better or worse. If the car gets better with just one tube connected, than 20,000 is too thick. If if it gets worse, then 20,000 is not thick enough. Lately 20,000 has been my default tube lube and I go up or down slightly from there depending on track conditions.
vafactor has it right on - this is where to start sorting out your double-steer, right out of a setup guide. solid advice! I bet this will tidy things up in no time.
On thing to consider - you were proposing changing shock fluid, shock spring, side dampening fluid and side spring? Make sure and do these ONE AT A TIME. Otherwise, you have no idea which adjustment had the desired handling change. Start with the dampening fluid as VaFactor recommends and probably about a 90% chance you won't need to touch the other setup changes you proposed.