05gt suspension question
#1
05gt suspension question
new to this form, I’m about to buy some lowering springs for my car and was just wondering if I will NEED to get a new Panhard bar and cast camber plates I’ve read some places that I will need it just wanted another opinion.
#2
Depends how low you plan on going.
You don't "need" a panhard bar, but if you are going to then you get an adjustable
one, and relocation brackets. It’s purpose is to locate the rear axle along the
centerline of the chassis. Raising the track bar makes the car looser (oversteer)
and lowering the track bar makes the car tighter (understeer). Adjusting the right
side track bar end upward moves the rear axle to the right, and therefore both rear
tires. Adjusting it downward moves the rear axle to the left, and therefore both
rear tires.
Front Camber, if you are going to lower it over an inch or so, it can throw the camber off.
You don't "need" a panhard bar, but if you are going to then you get an adjustable
one, and relocation brackets. It’s purpose is to locate the rear axle along the
centerline of the chassis. Raising the track bar makes the car looser (oversteer)
and lowering the track bar makes the car tighter (understeer). Adjusting the right
side track bar end upward moves the rear axle to the right, and therefore both rear
tires. Adjusting it downward moves the rear axle to the left, and therefore both
rear tires.
Front Camber, if you are going to lower it over an inch or so, it can throw the camber off.
#3
Eibach offers camber bolts that correct the camber change that results after installing lowering springs in the front. I used them after installing the Proline kit on my 05 convertible and it worked great, no need for caster/camber plates on my application. As to the panhard bar, I installed an adjustable one initially so I don't know how far off center the rear end would have been but its worth a shot to see before buying an adjustable panhard bar how far off the rear end will be after installing the rear springs. My panhard bar installed in the original place, I did not install relocation brackets. Hope this helps keep the costs down for you
#4
Thank you both for your advice, I ended up finding a Brand new UMI adjustable panhard bar for $50 off a buy n sell so that was a score, also I will probably just end up buying eibach’s 1.5” lowering springs and from the sounds of things most likely camber plates. I appreciate your guy’s advice!
#5
Since you got an adjustable one, make sure you measure where the chassis is at each
wheel, and adjust accordingly. I put a J&M on, and the body was pushed to the right
a little, so the driver side tire sticks out about 1/4" more than the passenger side.
THIS, is a great video that shows how the panhard rod works, and the geometry of it all:
wheel, and adjust accordingly. I put a J&M on, and the body was pushed to the right
a little, so the driver side tire sticks out about 1/4" more than the passenger side.
THIS, is a great video that shows how the panhard rod works, and the geometry of it all:
#6
Interesting . . . though I'm convinced that he should have also said that what he's doing by offsetting the axle slightly is to split the lateral travel equally in the left and right directions rather than piling all of the motion into only one direction (what you'd get if you centered the wheels in the chassis at roughly static ride height.
This is kind of a picky detail, so I'm going to take my turn at being picky . . . when doing this half-sagitta/splitting the lateral travel thing, you really should place weight in the car corresponding to the weight(s) and location(s) of the driver plus any occupants, with half a tank of fuel, and make this your design condition for setting the PHB to be level.
With no weight in the car, the PHB will not be at the same inclination as it will be with the weight in it. For the driver only in an early S197 - and I'm assuming OE-ish spring rates here, there could easily be a 5/16" change in the chassis-side bolt height due to the driver alone, about the same amount of change going from a full tank of gas to nearly empty, and about a quarter inch from the spare tire and jack (assuming that you would remove those things when you're chasing max performance). Over an inch total by the time you add a passenger.
I'm betting that this is why the PHB isn't sitting level with the car empty in its 100% original condition - Ford is setting the PHB to be level at some total gross weight ride height, which would be an actual operating condition. Being somewhat 'off' with the car just sitting there empty and not being driven doesn't matter at all.
Of course, if you have stiffer than OE springs, the amounts of ride height change will be less, though very few (if any) aftermarket "big springs" (non-coilover) are stiff enough to drop those numbers to half their OE values.
"Sagitta" isn't a very well-known term at all (it's not even among the top three hits on an internet search), and telling people to use half of that doesn't tell most of them what it is they're physically trying to accomplish. I have to admit that I'd never heard the word before either in school or over the course of about 40 years as an engineer. Though it has crossed my mind to split the lateral motion.
Norm
This is kind of a picky detail, so I'm going to take my turn at being picky . . . when doing this half-sagitta/splitting the lateral travel thing, you really should place weight in the car corresponding to the weight(s) and location(s) of the driver plus any occupants, with half a tank of fuel, and make this your design condition for setting the PHB to be level.
With no weight in the car, the PHB will not be at the same inclination as it will be with the weight in it. For the driver only in an early S197 - and I'm assuming OE-ish spring rates here, there could easily be a 5/16" change in the chassis-side bolt height due to the driver alone, about the same amount of change going from a full tank of gas to nearly empty, and about a quarter inch from the spare tire and jack (assuming that you would remove those things when you're chasing max performance). Over an inch total by the time you add a passenger.
I'm betting that this is why the PHB isn't sitting level with the car empty in its 100% original condition - Ford is setting the PHB to be level at some total gross weight ride height, which would be an actual operating condition. Being somewhat 'off' with the car just sitting there empty and not being driven doesn't matter at all.
Of course, if you have stiffer than OE springs, the amounts of ride height change will be less, though very few (if any) aftermarket "big springs" (non-coilover) are stiff enough to drop those numbers to half their OE values.
"Sagitta" isn't a very well-known term at all (it's not even among the top three hits on an internet search), and telling people to use half of that doesn't tell most of them what it is they're physically trying to accomplish. I have to admit that I'd never heard the word before either in school or over the course of about 40 years as an engineer. Though it has crossed my mind to split the lateral motion.
Norm
Last edited by Norm Peterson; 11-22-2018 at 04:13 PM.
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