Panhard bar relocation discussion

[scmscout]

If you use the Kenny Brown panhard bar relocation kit you will not need a rear sway bar.

 

[Norm Peterson]

If you use the Kenny Brown panhard bar relocation kit you will not need a rear sway bar.

Not sure I'm following this - unless the KB PHB relo kit moves the PHB upward.

Relocating the PHB downward would result in more roll, and a need for more rear bar rather than less.


Norm

 

[302 Hi Pro]

Not sure I'm following this - unless the KB PHB relo kit moves the PHB upward.

Relocating the PHB downward would result in more roll, and a need for more rear bar rather than less.


Norm

Hi Norm:

I’ve ran KB Suspension components since 2012 after their S197 Boss 302 Championship season of 2011.
Just to clarify, the KB Roll-Center Relocation Kit Or PB Relo Kit referred to here actually moves the PB down.

When installed correctly the PB position should be near horizontal (level) & about 5.0-6.0” below the centerline of the axle tubes.

The factory PB interferes with the KB relo brackets & cannot be reinstalled.

It’s a sweet setup. Hope this helps.




Notes: After this season we lost KB’s son Paul to cancer in October 2012. (R.I.P.)
Paul was a great drive.

2011 Pirelli World Challenge GTS Drivers Championship.
2011 Pirelli World Challenge Manufacturers Championship - Ford.
Paul Brown also Tied Parnelli Jones’ 1970 single season win record in a BOSS Mustang.

 

[scmscout]

Norm, as 302 Hi Pro stated, lowering the bar lowers the roll center. The roll center is located were the panhard bar or even a watts link is located vertically on the center line of the rear end housing.
Kenny Brown does not get a lot mention on this site but the guy really knows Mustang and sells some really good nice products that can transform your car!

 

[Boss4Me]

Norm, as 302 Hi Pro stated, lowering the bar lowers the roll center. The roll center is located were the panhard bar or even a watts link is located vertically on the center line of the rear end housing.
Kenny Brown does not get a lot mention on this site but the guy really knows Mustang and sells some really good nice products that can transform your car!

I have Kenny Brown’s Rear Grip kit with relocated Adjustable PHB and the other 3 links. No R sway bar. The transformation over stock is amazing to improve drive off. I have Kenny’s H&R coilover setup ready to install if we ever get out of lock down in MI. If interested Kenny is doing Car&Coffe Saturday mornings at 11 am EDT on FB Kenny Brown Perfomance

 

[DocB]

Nice setup.
Could you please show a picture of the RLCAs front and rear as they are bolted into the brackets? TIA.

 

[Boss4Me]

Nice setup.
Could you please show a picture of the RLCAs front and rear as they are bolted into the brackets? TIA.

The only pic of the install is as shown,

 

[Fabman]

When you move the roll center away from the center of gravity you get increased body roll but also better inside tire compliance. When you move the roll center closer to the center of gravity you get less body roll and less inside tire compliance.
Lowering the rear roll center tightens the car up, raising it loosens it up.
Lowering the roll center does not limit body roll, it increases it.

 

[Boss4Me]

When you move the roll center away from the center of gravity you get increased body roll but also better inside tire compliance. When you move the roll center closer to the center of gravity you get less body roll and less inside tire compliance.
Lowering the rear roll center tightens the car up, raising it loosens it up.
Lowering the roll center does not limit body roll, it increases it.

So two follow up questions; By lowering roll center...
1) Is increased body roll is recovered with spring rate and sway bar?
2) by tighten up do you mean adding understeer or push (front of the car hits the wall first)?
I’ve only installed and used the rear grip change which gives lower roll center. The increased spring rate coilovers to be installed someday after stay home is lifted. Then maybe there will be open track days this year.

 

[Fabman]

So two follow up questions; By lowering roll center...
1) Is increased body roll is recovered with spring rate and sway bar?
2) by tighten up do you mean adding understeer or push (front of the car hits the wall first)?
I’ve only installed and used the rear grip change which gives lower roll center. The increased spring rate coilovers to be installed someday after stay home is lifted. Then maybe there will be open track days this year.

Yes on both counts.

 

[Fabman]

*Weight transfer happens*
When you increase the lever arm between the Center of gravity and the roll center, lateral acceleration is expressed as body roll about the roll center (bite) rather than through the tires contact patch (slip).

 

[Fabman]

Think of it this way:
Take an ear of corn. Now stick those poky things in the ends that allow you to hold it without touching the corn. (handles) You'll notice that the corn is in a steady state but you are free to twirl the corn around it's center of gravity and stop it with little effort. Now re poke those handles towards the bottom of the corn. Notice that now the corn wants to flop over and you need to grip the handles more tightly (Springs and bars) to resist the corn from rotating because the center of gravity is acting against the roll center with a larger lever. You have just experienced roll center vs cener of gravity.

 

[Boss4Me]

*Weight transfer happens*
When you increase the lever arm between the Center of gravity and the roll center, lateral acceleration is expressed as body roll about the roll center (bite) rather than through the tires contact patch (slip).

Then lowering CoG to match lowered roll center reduces the the lever arm thus mitigating added body roll?

 

[Boss4Me]

Think of it this way:
Take an ear of corn. Now stick those poky things in the ends that allow you to hold it without touching the corn. (handles) You'll notice that the corn is in a steady state but you are you are free to twirl the corn around it's center of gravity and stop it with little effort. Now re poke those handles towards the bottom of the corn. Notice that now the corn wants to flop over and you need to grip the handles more tightly (Springs and bars) to resist the corn from rotating because the center of gravity is acting against the roll center with a larger lever. You have just experienced roll center vs cener of gravity.

That is a clear visual

 

[Fabman]

Then lowering CoG to match lowered roll center reduces the the lever arm thus mitigating added body roll?

Yes, but the center of gravity is difficult to do in large amounts.
By all means, lower it as much as possible but moving the roll center is far easier and more practical to achieve.

 

[Boss4Me]

Yes, but the center of gravity is difficult to do in large amounts.
By all means, lower it as much as possible but moving the roll center is far easier and more practical to achieve.

Lowering RH will be more about leveling vs slamming. Beyond these suspension changes there is no grand plan for weight reduction. Next steps might include brakes so some rotating mass reduction.

 

[Fabman]

Lowering RH will be more about leveling vs slamming. Beyond these suspension changes there is no grand plan for weight reduction. Next steps might include brakes so some rotating mass reduction.

I'm speaking conceptually, of course. I'm not suggesting you destroy the suspension geometry in pursuit of a lower CG. There are practice limits to everything.

 

[Boss4Me]

I'm speaking conceptually, of course. I'm not suggesting you destroy the suspension geometry in pursuit of a lower CG. There are practice limits to everything.

Agree with limits so I try to remember my goals and go off the edge

 

[Grant 302]

Not sure I'm following this - unless the KB PHB relo kit moves the PHB upward.

Relocating the PHB downward would result in more roll, and a need for more rear bar rather than less.

@Norm Peterson

I separated this topic so this part could be discussed aside from the 20mm sway bar thread.

But I challenge the conventional thinking that lowering the roll center results in more body roll...and ‘need’ for more rear bar.

Having a greater lever arm only changes the rate that the car rolls (and transfers weight faster), but ultimately does not limit the roll as springs and bars do.

Since both sway bars and lowering the roll center increase rate of lateral transfer, I believe Kenny Brown is correct in his claim that his PHB relocation kit does reduce the need for rear sway bar or rate.

——

I also believe there are benefits in keeping the PHB closer to level as Dave mentioned. Primarily for being more consistent in left vs. right turn behavior. The rate of transfer varies much more as static PHB angle increases.

 

[Fabman]

@Norm Peterson

I separated this topic so this part could be discussed aside from the 20mm sway bar thread.

But I challenge the conventional thinking that lowering the roll center results in more body roll...and ‘need’ for more rear bar.

Having a greater lever arm only changes the rate that the car rolls (and transfers weight faster), but ultimately does not limit the roll as springs and bars do.

Since both sway bars and lowering the roll center increase rate of lateral transfer, I believe Kenny Brown is correct in his claim that his PHB relocation kit does reduce the need for rear sway bar or rate.

——

I also believe there are benefits in keeping the PHB closer to level as Dave mentioned. Primarily for being more consistent in left vs. right turn behavior. The rate of transfer varies much more as static PHB angle increases.

Plenty of documentation out there. I suggest anyone interested to look it up for yourself.

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"In a turn, a car transfers weight from the inside of the car to the outside of the car due to centrifugal force. That means more weight moves from the left side to the right side in a turn. When the rear axle is moved to the right, more weight is moved to the left of the centerline. This allows more weight to transfer during cornering (more body roll)."

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