ran my 2nd AutoX event with my new pan-hard bar relocation, I like the extra rear grip BUT:
I Noticed an absurd amount of body-roll due to lowing the roll center in the rear by 3in.
what springs are you guys running with re-located PHBs?
I've seen guys run 400lb springs, but is that excessive for a Koni Yellow to dampen?

I'm currently running 200lb rears on weight-jacks with a 23mm bar.

 

I used 350lb in the rear for a bit and the 3rd gen koni yellows work just fine.

 

Just be aware, adding more spring rate in the rear will increase oversteer. Also adding more rear sway bar will do the same but to a much lesser degree.

 

Too much spring, you're gonna oversteer something bad, work with what you have and make slight adjustments, are you oversteering now? make sure you have tuned the front to match and that you have the tire to handle the grip. 400# might work for someone who has the tire to make the rear stick. Just throwing springs at it isn't gonna fix other problems you might have(if you actually have them) you may just have maxed your car out and need other things to go faster. It's not necessarily the shock that determines the effectiveness of the spring.

 

I fabbed up a bracket to use old front IROC springs on the rear of my car out of curiosity. It was terrible. Rear end would jump on every bump and make it virtually undriveable. I’ve never seen one of these cars understeer before, so you’re going to want to keep the rear end soft. I’ve done several autocross events, and my car handles fairly well with replacement rear springs that I’ve “trimmed” to lower the car.

 

Why not just raise the panhard bar a bit until you like how it handles?

 

I moved the PHB up 1in for a total of 2in lower than the stock location.
Stiffened the front Koni DA and softened the rear Koni SA and it stopped oversteering and now under steers just a little bit at the limit.
Feels fairly good even AutoX events in the rain were no issue

But the rear roll is still HORRIBLE.
I'm kissing my bump stops in the rear.