Hi Steve,

Personally I recommend Steeda for their very stiff chrome-molly tubes,bombproof build quality,light weight andgood support.APanhard bar is not an item that youshould need support to install but if anything does go wrong Steeda will happily make it right. For example; I've had bushingsin my car that I've been abusing for a few years and when I askedabout orderingone newbushing for one of theLCA's that I must have managed to damage somehowwhile tinkeringwith my suspension(hey, someguys play with women, I want to stay married so Iplay with cars)they looked up my car's suspensionsetup and sent the whole kit and kaboolde and they arrivedgratis! I'm not talking about a couple of pieces of poly hereas I'veinstalled literally the whole Steeda suspension catalog in my car front and rear. They sent mebushings forboth ends of bothLCA's, the new improved 3-piece bushings for their adjustable UCA andboth ends of the Panhard bar. So if I seem a bit biasedI have good reasonto be. Not only is theSteeda suspension stuff designed and engineerdto resolve the common suspension problemswe have they actually build these parts to last and actually fit correctly.

The FRPP springs are actually just Eibach Pro-Kit Sport springs. The FRPP/Pro-Kit springs lower the car prettymuch 1.4"/1.7"and you wil notice improved stability in a straight line and in the corners. But this isdoes not come freedue to changesthat happened when you lowered the car. The biggest problem is the change in IC (Instant Center) which is why you can now spin the tires without even tryingand thehuge increase in roll understeer which is where you get all of that extra stabilityfrom. The fix for this is to install a set of LCA relocation brackets so you can set the LCA's at an angle that is favorable to your use. For strret and handling you need to set the LCA's level with the ground. To do this you need LCA brackets with as many possible adjustment holes as you can get. Steeda makes the LCA brackets wih the most adjustment holes but they are also weld-on only and require a good suspension knowledgableshop to install accurately to prevent dog-tracking.

You could alsojust wait and see if you think thesuspension is working O.K. for you. If you don't mind getting beaten by cars you should be able to kill from a dig the LCA brackets are not needed. But I doubt you would go for that now would you?

HTH!

 

Thanks for the information...

I actually ordered the BMR panhard bar and Panhard Brace, BMR A frame connector, BMR Box subframe connectors, BMR LCA relocation brackets...

Next is aluminum drive shaft, draft shaft safety loops, slotted rotors and new brake pads..

Want to make sure chasis and driveline, brakes will tolerate future power upgrades.

Steve

 

Right about here I have to ask a question - just how far off the horizontal is the PHB in its OE configuration in anybody else's car?

I've been able to make a couple of crude measurements on mine, but they at least agree with a visual comparison of pivot bolt elevations relative to the axle tubes. Long math story short, I'm only looking at about 1/16" of axle motion involved with enough lowering from where it is with the car unoccupied to put the PHB dead level (after which point further bump travel causes the axle's lateral movement to reverse direction). Note that some of that 1/16" I got is fictitious because the measurements were not made with a driver seated behind the wheel. I really don't think the pivots could physically be 8" apart vertically (for 3/4" axle movement).

I find it hard to believe that the factory build is bad enough to require axle lateral relocation even on the order of half an inch.

Is it possible that the before and after measurements in some of these cases were not taken under consistent conditions? IOW, measurements taken with the rear wheel contact patches in one plane before but in a different one after?


Norm

 

Hi Norm,

I have not measured a stock Panhard Bar angle as I never though to take this measurement. I will be working on a new Bullitt in a week or two and will measure the angle of the stock car befroe I install the Steeda adjstable Panhard Bar and HD Panhard bar brace. I'm not sure if this will help much as the Bullitt'shave aslightly lower stock ride height.

But assumming we have thestock length Panhard barwhich is about41.75" center to center and allow for a conservative 5" total axle travel from full droop to full compression positions you have a total of about 0.19" shift in lengthif we assume that the carhasfull stockaxle travel which means thePanhard bardoes not reverse the direction ofaxle movement ina full stroke. The weirdness begins when the caris lowered and the Panhard bar is level or just aboutlevel. What happensis thatas the axle moves up and down through its travel it has to move left and then right as it passes through the center of thePanhard bar's travel when traveling full stroke.This is part of the weird handling things you can feel when the PB is setup parallel to the ground. This is alsowhatI think many people are feeling when turning sharply leftor right and feel the differences in turning. This weirdness you can feel I think is caused by thePanhard bar loading and then unloading again as it moves through its travel.

I have also seen thisimpossible to believe amount of axle movement. I swear it comes from the Panhard bar moving on its pivotand not being well located even when the fasteners are fully torqued to factory specs. My own car displays this some times and I always use a known good torque wrench with a 2% precision spec.

Cheers!

 

I'll add two words here. Body roll. Analyzing the effects of the panhard bar's geometry without discussing body roll is a waste of time.

 

Something's missing here. At this point anyway, I'll stipulate to a 41.75" PHB length (I saw what I think was closer to 42" but this is not the time to worry about 1/2% stuff). I got ~2" difference in pivot heights, unloaded, and my car has to be as close to "design height" as any out there since I have done nothing to alter that in any way (yet). There's a MVMA document for the 2005 model year S197 that puts rear bump travel at 3.5" and rebound at 4", meaning that full bump travel necessarily causes the PHB to become level about midway into the bump travel.


This is where it's going to get a bit more complicated, maybe a lot more when the appearance of a PHB is that it's such a simple link. Been trying off and on to wrap my brain around it since . . . well, the thread elsewhere does still exist (I checked ). A PHB does not completely decouple vertical and lateral forces, and I'm not at all convinced that it provides any inherent contribution toward defining the lateral location of a kinematic roll center. I suspect that in order to understand the movement that results from a PHB that there is some sort of 'anti' property involved, as well as the stiffnesses of the springs/bars/etc. If you're familiar with Mark Ortiz's "Chassis Newsletter", perhaps you've seen his discussions involving "anti-roll" properties of independent suspensions. This sounds like a force-based roll center approach, and I think it's what it really takes to see what's going on. A purely kinematic approach seems insufficient, especially when you have both ride and roll motions occurring simultaneously.



Has anybody else looked to see wherethe rear axle LCAs might converge?


Norm

 

Hi Norm,

I just took a tape measure to the stock Panhard bar sitting out in the garage on the floorand eye- balled it at about 41.75" so this was just for conversation and to calculate the length of the PB movement. As to the full suspension travel I was also justarbitrarily using5" for for thesame calculation guestimating the movement at the PB not the tires.What I was trying to illustrate was thatas the car is loweredthe PB is more nearly parallel to the ground. And due to this fact thedriver will have the opportunity to feel the wierdness of the Panhard bar movingthroughthat odd period when the movement of the axleand the forcesworking on both the axle and the Panhard bar which is trying to send those forces into the chassishave to reverse themselvesmoreoften than a car with stock ride height. It'sone of the problems with Panhard bar cars thatAFAIK that is unique to this type of rear axlelateral location.Can you help me with the MVMA acronym? I'm unaware of the Chassis Newsletteris it interesting? Where can I seeprevious issues? I used to have a pretty good measurement of where the sideviewUCA/LCAlines intersected but that set of notes has been lost I'm afraid. But is this what you are looking for or are you interested in where the two LCA's intersect in front of the car? I may be able to tell you where they intersecton a Stock Bulliitt in a few weeks.

Cheers!

 

[align=left] Eventually, I'm looking for XYZ cooordinates of all the various pivot points. I mentioned the LCAs because of what I thought I was seeing when I measured up the PHB. Something. . . just looked different from what I was expecting to see, but it wasn't at all convenient at that time to make the necessary measurements to be sure. I was hoping somebody else already had. Think plan view skew and its implications.

MVMA should have read MVMS and is 'Motor Vehicle Manufacturer's Specifications'. I only have the 2005 year, and it's about a 3.6MB pdf file.

Chassis Newsletter is a brief internet publication written by Mark Ortiz. I have copies dating back to the fall of 2000, though I haven't been a subscriber for nearly that long.

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