Panhard Bar Question

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Supercharged111
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Panhard Bar Question

Postby Supercharged111 » Sun Oct 25, 2015 6:16 pm

Here's the Rule:

7.33.2 Panhard bars:
1. Ford cars may add a panhard bar. The bar may be adjustable for length. One panhard bar mounting point may be height adjustable to allow for leveling of the bar, but the other mounting point must be of fixed height.
2. GM cars may substitute the OEM panhard bar. The bar may be adjustable for length. The passenger side mounting point must remain OEM stock. The driver side mounting point may be lowered, but only to the point where the panhard bar is parallel to the axle at ride height.


So the Fords can have a perfectly set up panhard bar but us GM guys can't? IMO the fixed point for the Fords panhard bar should be spec'd in the rules and it should suck just as badly as the placement of the GM's.
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mach1
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Re: Panhard Bar Question

Postby mach1 » Tue Oct 27, 2015 7:30 pm

What sucks about the fixed height of the GM panhard bar?

Supercharged111
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Re: Panhard Bar Question

Postby Supercharged111 » Wed Oct 28, 2015 8:37 am

Honestly it might be in a good spot. Being able to change it means being able to change your roll center, so when the bar is added to a Ford the chassis mounting point can be set wherever the owner wants it to be and then locked in. Ride height affects this too. Nowhere else in the rules are we allowed to change roll centers, so I don't think we should here either which is why I think all Ford guys with Panhard bars should have that inboard mounting point specified in the rules.
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Glenn
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Re: Panhard Bar Question

Postby Glenn » Thu Oct 29, 2015 8:15 pm

I fought this rule way back when many years ago.
The original rule for the GM was odd. I was "fixed" to only allow the driver side to be adjustable. Reason is, the highest the car needs to be puts the PHB almost level. If you keep going down, the body side (pass) will end up lower than the axle side (driver). So only one side needs to be adjustable.
The rub came when the Ford could add one w/out restrictions. This potentially allowed an advantage for the Fords as they can now build in a lower rear roll center w/ the PHB without having to use ride height to manage it.
Dropping the car lowers CG, but at the risk of the suspension getting at funky angles. There is a trade off. Dropping the PHB drops the RRC.
W/ the GM's this is all a compromise. We lower the car as much as the suspension will allow until handling is affected, then we stop and set the PHB level, living w/ the RRC we get. We can only level it, not target a set RRC height.
W/ the Fords, you can now set the ride height you want that gets the best CG/handling return w/out getting into the handling trade off zone. Then you can build the PHB @ whatever starting height you want getting the ideal RRC. If you don't like it, cut it all off and start over. And if one side can't be made adjustable, you can redesign it to be where you would want to adjust it to.

PHB Rule - Ford for the Win!

What is the fix? Well there is no OEM set-up from Ford to copy, so that is out. If you set a chassis point where it had be placed on the body side, where would that be? Would the point we pick cause a GM advantage? Ford advantage? Who knows.
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TX#11CMC
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Re: Panhard Bar Question

Postby TX#11CMC » Fri Oct 30, 2015 5:00 am

I just look at it as the PHB is one area where the Fords have an advantage, same as their advantage with a lesser weight.
Its no different than the GM's advantage w/ track width, aero, etc.

We are never going to be able to make every car the exact same. Bottom line is, are the platforms equal?
-Michael Mosty
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BryanL
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Re: Panhard Bar Question

Postby BryanL » Fri Oct 30, 2015 11:17 am

TX#11CMC wrote: Bottom line is, are the platforms equal?


Now why didn't you open that can of worms around the campfire at TWS while watching Bathurst 1000!!!!!!!!!!!!!!!!!!!!!!!!!

If you use the same information that CMC11 lobbied with to make changes a few years ago, then no they aren't equal. The question is how close to equal are they? Bring in the data recorders and use more than 4 sessions on 3 different cars to make that determination please.


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