Panhard bar VS. reinforcement bars
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Kingrocpage12
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Panhard bar VS. reinforcement bars
A few ppl have told me to use reinforcement bars over a panhard bar on my 87 monte SS , just curious Wat u guys think??? Any help is appreciated....... Or is it overkill to use both
Re: Panhard bar VS. reinforcement bars
They serve completely different purposes, so you'll have to explain to us what you are doing with the car.
A panhard rod is a link that locates the axle side to side while guiding it up and down. Doing this requires that the vehicle's original axle side-to-side locating mechanism - the two angled control arms at the top of the axle - have to be relieved of that function (i.e. removed) to avoid binding and you now need some other mechanism of absorbing axle torque reaction (i.e. a single upper link or a torque arm like some of the Grand Nationals had). Whether the resulting 3-link-plus-panhard will be "better" than the original 4-link ... is open to question and very much dependent on whether the geometry is correct or you get it all wrong. Compare Mustang S197 (3-link plus Panhard) to Mustang Fox-body (quadralink a.k.a. "quadrabind").
Reinforcement bars - that is a very vague term - presumably just beefing up the original chassis attachment points to avoid some sort of adverse deflection.
Keep in mind that the geometry of your original 4-bar linkage requires the links to twist in their mountings slightly as the suspension moves up and down. A link that is intentionally not very stiff in torsion and/or has compliant bushings at either end, is the original design intent from GM. Beef those arms up without making any allowance for them to move around - which they have to do - and you have what the Fox-body Mustang folks call "quadrabind" suspension.
If you are putting 1000 horsepower to the rear end to go in a straight line down a drag strip, the side-to-side location and binding with suspension movement in roll probably don't matter much but the reinforcement (and the anti-squat geometry) matter a lot. If you want to go around corners on an autocross or roadrace track, it's the other way around.
A panhard rod is a link that locates the axle side to side while guiding it up and down. Doing this requires that the vehicle's original axle side-to-side locating mechanism - the two angled control arms at the top of the axle - have to be relieved of that function (i.e. removed) to avoid binding and you now need some other mechanism of absorbing axle torque reaction (i.e. a single upper link or a torque arm like some of the Grand Nationals had). Whether the resulting 3-link-plus-panhard will be "better" than the original 4-link ... is open to question and very much dependent on whether the geometry is correct or you get it all wrong. Compare Mustang S197 (3-link plus Panhard) to Mustang Fox-body (quadralink a.k.a. "quadrabind").
Reinforcement bars - that is a very vague term - presumably just beefing up the original chassis attachment points to avoid some sort of adverse deflection.
Keep in mind that the geometry of your original 4-bar linkage requires the links to twist in their mountings slightly as the suspension moves up and down. A link that is intentionally not very stiff in torsion and/or has compliant bushings at either end, is the original design intent from GM. Beef those arms up without making any allowance for them to move around - which they have to do - and you have what the Fox-body Mustang folks call "quadrabind" suspension.
If you are putting 1000 horsepower to the rear end to go in a straight line down a drag strip, the side-to-side location and binding with suspension movement in roll probably don't matter much but the reinforcement (and the anti-squat geometry) matter a lot. If you want to go around corners on an autocross or roadrace track, it's the other way around.
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Kingrocpage12
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Re: Panhard bar VS. reinforcement bars
Ok the reinforcement brace bars that I'm talking about bolt from the lower trailing arm to the upper trailing arm which are the ends tht bolt to the frame .... UMI makes them and I've seen a bunch of other companies make them ... But I'm planning on getting them along with the adjustable tubular trailing arms and I have a 12 bolt rear end with relocated brackets on it already .... I was also curious about a rear sway bar tht is chassis mounted.... Wat exactly is the use of tht??? Thanks
Re: Panhard bar VS. reinforcement bars
OK ... Those brackets are meant to beef up the chassis so that sending vast amounts of power to the ground through drag-racing slicks don't rip the control arms out of their mountings. The stronger trailing arms (lower links) are to resist collapsing under the same sort of loading conditions. If that's what you are doing with the car (you still haven't told us ...) then you gotta do what you gotta do. A panhard rod will not serve that purpose.
An antiroll bar is essentially a torsion spring between the left and right sides which counters body roll when cornering. My background is roadracing so I understand why one would want to do that in order to balance the chassis (understeer versus oversteer when cornering). Drag race cars don't turn corners (except slowly, near the timing shack ...) but front engine rear drive cars with a live rear axle have an issue with the drivetrain wanting to twist one way while twisting the axle the other way when accelerating hard, and I'm sure that adding (considerable) roll stiffness might help countering this. Live rear axles can either have the antiroll bar mounted on the axle and travel up/down with the axle with links up to fixed points on the chassis, or they can be mounted on the chassis and have links down to the axle. Makes no difference as far as roll stiffness is concerned. The chassis-mounted type has a little less unsprung weight (because the whole bar isn't bouncing up and down with the axle as the axle follows the path of bumps on the road) but that's a roadracing thing again. I don't think drag racers care about unsprung weight.
An antiroll bar is essentially a torsion spring between the left and right sides which counters body roll when cornering. My background is roadracing so I understand why one would want to do that in order to balance the chassis (understeer versus oversteer when cornering). Drag race cars don't turn corners (except slowly, near the timing shack ...) but front engine rear drive cars with a live rear axle have an issue with the drivetrain wanting to twist one way while twisting the axle the other way when accelerating hard, and I'm sure that adding (considerable) roll stiffness might help countering this. Live rear axles can either have the antiroll bar mounted on the axle and travel up/down with the axle with links up to fixed points on the chassis, or they can be mounted on the chassis and have links down to the axle. Makes no difference as far as roll stiffness is concerned. The chassis-mounted type has a little less unsprung weight (because the whole bar isn't bouncing up and down with the axle as the axle follows the path of bumps on the road) but that's a roadracing thing again. I don't think drag racers care about unsprung weight.
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Kingrocpage12
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Re: Panhard bar VS. reinforcement bars
Yes I'm building a race car but I still want it street able .... I plan on being in the high 8's low 9's