scottybaccus

I dropped my 2011 V6 1.7" in the rear using Eibach Sportline springs. I measured today and found the axle to be 1/8" to the right, well within tolerance, still using the OE panhard bar.

Just a note on the strength of that double adjuster stud in the middle of the bar on some aftermarket panhard bars; That should be a 3/4"-24 thread, maybe 5/8"-18. Going by the tensil strength of even a cheapo rod end having a 5/8-18 shank, it is rated at 25350 psi. By design, the panhard only sees tension and compression in lateral Gs pulling a corner. Supposing the tires never slip, the rear of a car weighing 1200 lbs or so could only apply that much force to the panhard in a 1 G turn. (excluding shock levels like hitting a curb or something) That means you would need something like 20 Gs in a corner to approach the limits of that piece. I very seriously doubt anyone is bending ANY panhard bar outside of a curb strike or crash. In fact, if you look at the weakest part of the whole assembly, it would be the outer wall of the bushing tube on each end. You would see the bolts cutting the urethane bushings before you saw enough force to hurt the adjuster.

Just sayin'...

jlc41

Very interesting...who knew???? (:>

HOTRODD77

Well I'm going to be doing steeda sports, so not a significant drop. Not sure I'll have to mess with the control arms. I don't track the car, so I'll just be on the streets.

Jazzer The Cat

Your right, but the weak link in the bar is a "break" between the ends. Regardless of where it is, the closer to the end, the better. This bar will flex under load and the weakest link is this joint. All else being equal, the bar will be stronger with less flex with a joint closer to the end.

Jazzer

ModMe

mine is dropped 1.3" in front and 1.4" in back and really didn't see that much of a shift. I did the panhard bar anyway cuz I got such a good deal on it.

scottybaccus

So chassis fab is what I do semi-pro for fun. It used to pay the bills, but I make a lot more money in corporate America, so it's a hobby now. I've built a lot of panhard bars from scratch and would never use a double adjuster in the middle, unless there was a real space issue that just made it easier to get to. The type i like look a lot like any of the other aftermarket parts, moly tube, tube adapters, kevlar lined rod ends and seals, so I won't be ordering one up anytime soon. Based on my measurements yesterday, I don't NEED one, but I did note one thing. The angle that the bar is in at static ride height is a little steeper than I would like. The axle end is higher than the chassis end, which will cause the axle to move only in one direction as the suspension compresses. By design, it should be that the axle end is slightly below level, allowing the axle to criss-cross that small arc at the center of level. That actually minimizes side shift and keeps it from being biased either way. (it can really only bias one way from level)

What I see missing from the market is a modifed mounting point that allows you to return the panhard to level. Even with an aftermarket panhard, it would still be running uphill at my present chassis position. Has anyone seen a part that repositions one end of the bar? I may be out there fabbing parts this weekend, if not.

Jazzer The Cat

You are correct, the bar is nearly always angled up to the body. Level would certainly "balance" the travel of axle from a side/side stand point. Personally, this has never been an issue for me and run 11" wheels out back.

My only complaint about the PHB is it seems to respond differently depending on which way I am turning. My bar happens to be LOWER on the body side and partly due to the aggressive drop I run on my ride. I will be talking to John this week about upping my spring rate out back and possibly the fronts. I will dig his mind a bit on my theory.

Jazzer

scottybaccus

You are absolutley correct on turning behavior. The panhard bar creates bias in the roll center. Think about the moment you throw the car into a corner, the weight shifts around the axle, that is theoretically fixed on the pavement. While the actual roll center is in a hard to pinpoint place in space, the point of mechanical rotation is the end of the panhard bar. Since it isn't symetrical, the rotation of mass around the rear axle is different from one direction to the other. A street car is a toss-up on which is better, but the left hand racers are very particular.
It might be interesting to dig up some reading on how a Nascar chassis is adjusted to go from a big oval to a road course.

Norm Peterson

I would not be surprised to find the PHB chassis-mounted on the driver side in at least some of the cars out at Infineon this weekend and at Watkins Glen later on (unless NASCAR has mandated otherwise).


Norm

Jazzer The Cat

My bar is actually a bit lower on the body side (passenger). I have given a bit of thought to how this effects the load on LH vs. RH corners. Seems to me that on RH corners, the body would remain either a bit more level or at least be less inclined to be un-naturally elevated on the passenger side. On a LH turn, I suppose the body may dive a bit more. I suppose this may account for an additional bit of understeer on such a corner. What say you, Norm?

You can see a bit of the results (approx. :55 sec. mark) in the following vid from AX last weekend. I suppose a bit of "overzealousness" upon exit had a bit to do with it