This debate seams to come up every year or so. DO a search.
Panhard bar is lighter than a Watts Link = Less sprung weight.
Rear roll center for a Panhard bar is determined by where it is situated to the ground.
It should be as low as possible and parallel to the ground at ride height.
I have driven the same car on track with a properly set up Panhard bar and then a Watts link. I could not notice any discernable difference in lap times or predictability between the two – Not on a S197 - Everything Heim Jointed.
They might act different on rough Auto Cross Course with quick and forced transitions. I don’t know some say yah some say nay. I chose to go with the weight savings on our S197. I didn’t relocate the Panhard bar as low as I would have liked because the development stopped.
Gentlemen – We have a heavy straight chunk of steel that both our rear tires are connected to.
When one tire come in contact with a bump it affects the other tire regardless of what we want.
Purchasing decent springs with dampers that can control that straight lump of steel would be my first suggestion. After that – How much money and time do you want to spend to make out boats predictable? Nothing wrong with a straight axle on a smooth surface but most places are not smooth.
OHH - This should stir the pot LOL.
My WL watts link is just 2 x short bars vs the long BMR adj PHB. The BMR PHB brace gets replaced with the WL equivalent. Oem diff cover gets replaced with a thicker aluminum cover. Difference in weight between the 2 x setups is minimal. Pass end of a PHB is bolted to the body, driver's side of PHB is bolted to the axle. Outer ends of my wl watts are bolted to the body, inboard ends bolt to the diff cover. How much is sprung weight and how much is unsprung ? I'd take the weight of the phb, and divide it in half.... since half is bolted to body and the other half bolted to axle.... and ditto with wl watts. So it comes out a wash.
On a lowered car, the phb is at a shallower angle vs oem phb..which is good. The steeda adj length phb is also adjustable in height..at both ends, so in theory, you should be able to get their phb almost parallel to the ground.
The BMR phb has a poly bushing at each end. My wl watts has a elastomer bushing at each end of each rod, so 4 in all...... vs just 2 for a phb. So you also have to factor in the compliance of 4 bushings vs 2.
How many bumps are you hitting on corners on your track ? Most tracks are pretty smooth for the most part. Even if they are not, you at least know where the bumps are, since it's a closed loop. Even on a rough autoX course, you know where the bumps are. Out on the street, it's a whole different ballgame. Around town here, bumps can change by the week. Some roads deteriorate over a few months, some are fixed, some get good repairs, some get lousy repairs. I never know what condition the roads will be on the other side of town, since I'm seldom over there. Even when I think I have it figured out, it will either change or I'll have a tough time trying to remember specific road condx, for hundreds of miles of road surfaces. At night, it's worse.
Bottom line is... the watts is planted on bumpy corners...and the poly phb isn't. From a safety point of view/inspires more confidence, I feel its worth it.