Do i really need the PHB if i drop my stang.?.?.?
10-19-2013, 09:08 AM
#91
6th Gear Member
Join Date: Feb 2007
Location: state of confusion
Posts: 7,635
"Lowered a lot" is probably Sportlines, which lower the rear quite a bit more than the front (which is what I think I'm seeing in a blown-up picture in Picture Manager with the midtones cranked all the way up).
If so, your PHB will be almost certainly be higher on the axle side than on the chassis side with you in the car, so a one-wheel bump especially on the driver side will have a tendency to push or pull the rear of the car sideways. Tired shocks or OE shocks combined with Sportlines won't be helping to minimize this at all, as they allow more suspension motion which induces larger lateral forces from the PHB.
I would also check the LCA bushings, looking for cracking or other signs of deterioration. If they're in bad condition, fore/aft location of the axle ends is not as good as it should be. Bumps, and especially one wheel bumps will move one axle end differently from the other, making it actually steer the rear of the car. A little of this is normal (and pretty much unavoidable). A lot means you have a potentially serious problem that needs to be fixed/corrected ASAP.
Norm
If so, your PHB will be almost certainly be higher on the axle side than on the chassis side with you in the car, so a one-wheel bump especially on the driver side will have a tendency to push or pull the rear of the car sideways. Tired shocks or OE shocks combined with Sportlines won't be helping to minimize this at all, as they allow more suspension motion which induces larger lateral forces from the PHB.
I would also check the LCA bushings, looking for cracking or other signs of deterioration. If they're in bad condition, fore/aft location of the axle ends is not as good as it should be. Bumps, and especially one wheel bumps will move one axle end differently from the other, making it actually steer the rear of the car. A little of this is normal (and pretty much unavoidable). A lot means you have a potentially serious problem that needs to be fixed/corrected ASAP.
Norm
10-20-2013, 07:46 AM
#93
6th Gear Member
Join Date: Feb 2007
Location: state of confusion
Posts: 7,635
Adjustable PHBs only adjust for length, not inclination. PHB inclination can be tweaked (there are a couple of kits that allow for different heights at one end of the PHB). Firmer PHB bushings will make the axle's lateral behavior a bit more predictable, which may be enough benefit to justify a PHB upgrade. But why bother throwing time and money at band-aiding the OE PHB's shortcomings when the stated ultimate goal is to run a Watts link?
FWIW, I changed out my LCAs at just over 25000 miles for the bushings-on-their-way-south reason. I have never drag raced it, don't ever powershift, and I have only experienced a half dozen episodes of mild to maybe moderate wheel hop. And the bushings had still started to crack, just from hard cornering and general use.
Check also the rear bump stops. If you're suddenly bottoming out on them as you're going over bumps you shouldn't expect the car to behave as well as it should when you stay off them. Even on what looks like a smooth road, there can still be an inch or so of suspension travel, over half of which would be in the 'bump' direction. I think most of this would be a Sportline-related issue.
There's a Fox-body Mustang in your background, right? Since its rear suspension is a considerably different arrangement than the S197's 3-link + PHB, there will be differences in feel that you'd tend to notice more right away until you get used to them. The triangulated/converging 4-link setup is inherently symmetrical in its behavior, which may "feel" better even though OE tri 4-link handling isn't up to the 3-link/PHB level. The rear suspension in the 1979 Chevy Malibu I used to have was very similar to the Fox.
Norm
FWIW, I changed out my LCAs at just over 25000 miles for the bushings-on-their-way-south reason. I have never drag raced it, don't ever powershift, and I have only experienced a half dozen episodes of mild to maybe moderate wheel hop. And the bushings had still started to crack, just from hard cornering and general use.
Check also the rear bump stops. If you're suddenly bottoming out on them as you're going over bumps you shouldn't expect the car to behave as well as it should when you stay off them. Even on what looks like a smooth road, there can still be an inch or so of suspension travel, over half of which would be in the 'bump' direction. I think most of this would be a Sportline-related issue.
There's a Fox-body Mustang in your background, right? Since its rear suspension is a considerably different arrangement than the S197's 3-link + PHB, there will be differences in feel that you'd tend to notice more right away until you get used to them. The triangulated/converging 4-link setup is inherently symmetrical in its behavior, which may "feel" better even though OE tri 4-link handling isn't up to the 3-link/PHB level. The rear suspension in the 1979 Chevy Malibu I used to have was very similar to the Fox.
Norm
Last edited by Norm Peterson; 10-20-2013 at 07:50 AM.
10-20-2013, 10:05 AM
#94
2nd Gear Member
Join Date: Jul 2013
Location: Shenandoah Valley of Virginia
Posts: 406
As to the need for an adjustable "Pan Hard Bar" to more precisely center the rear axle in a Mustang after lowering, if one side is like 1/4" closer than the other, only 1/8" movement is needed to center it at rest and that can be accomplished by "moving" the holes on either the frame mount or axle mount point. It does not get you more precise polyurethane bushings or heim joints ... but will let you center the rear axle.
One way is to file / grind with a dremel .... the original hole elongated only in the direction and amount of desired movement, apply a decent washer that fits the through bolt on each side, adjust and set and tighten to torque ..... and then if desired, a couple spot welds from washer edge to mount to prevent unintended "hole movement" while allowing for future movements by grinding small spot weld away.
Or one could use a pair of larger OD "fender" washers or 3/32" or 1/8" thick steel plates in same places and instead of spot welds, just use a couple 1/4" bolts at edges of washer / plate so no slip. The torqued OEM mount bolt will hold it in use.
Yes, GM used it in all those GTOs, 442s, Chevelles, etc ..... did OK it seemed.
Ford used it as well in the 1978-1997 LTD-Crown Vic / Merc GM "Panther" chassis (that is as well as Fox) which several years were bought by my department for patrol cars, and while we thought they were "OK" (Chevrolet also used it on the alternative police car, the "Caprice" chassis ... but it always felt tighter, I suspect either through harder bushings or steeper angles?).
When the 1998 CVPI came out with the new "Watts Link" setup ..... "WOW" certainly applied.
Where before you threw her into a curve and "instinctively" pre-countered for rear sway to set in .... suddenly there was little need as the car was so much better planted in back, more predictable.
One way is to file / grind with a dremel .... the original hole elongated only in the direction and amount of desired movement, apply a decent washer that fits the through bolt on each side, adjust and set and tighten to torque ..... and then if desired, a couple spot welds from washer edge to mount to prevent unintended "hole movement" while allowing for future movements by grinding small spot weld away.
Or one could use a pair of larger OD "fender" washers or 3/32" or 1/8" thick steel plates in same places and instead of spot welds, just use a couple 1/4" bolts at edges of washer / plate so no slip. The torqued OEM mount bolt will hold it in use.
There's a Fox-body Mustang in your background, right? Since its rear suspension is .... etc ... The triangulated/converging 4-link setup is inherently symmetrical in its behavior, which may "feel" better even though OE tri 4-link handling isn't up to the 3-link/PHB level. The rear suspension in the 1979 Chevy Malibu I used to have was very similar to the Fox.
Norm
Norm
Ford used it as well in the 1978-1997 LTD-Crown Vic / Merc GM "Panther" chassis (that is as well as Fox) which several years were bought by my department for patrol cars, and while we thought they were "OK" (Chevrolet also used it on the alternative police car, the "Caprice" chassis ... but it always felt tighter, I suspect either through harder bushings or steeper angles?).
When the 1998 CVPI came out with the new "Watts Link" setup ..... "WOW" certainly applied.
Where before you threw her into a curve and "instinctively" pre-countered for rear sway to set in .... suddenly there was little need as the car was so much better planted in back, more predictable.
Last edited by tbear853; 10-26-2013 at 01:44 PM.
10-21-2013, 11:52 AM
#95
Former Sponsor
Join Date: Sep 2007
Posts: 1,936
As a new S197 owner with a similar concern, I'd like to chime in.
On my two hour ride home after picking up my new car, I noticed over uneven bumps or road that the car shifted with no steering input. Kind of disconcerning. Then I remembered this chassis uses a PHB and this car is lowered a lot. Idk how much exactly but all I know is that they're Eibach springs, with a stock PHB. Maybe you guys can judge by the pic? The tires seem to be aligned with the fenders, but I haven't done a finger test to see, but now I know that doesn't really matter.
I know all about trig and arcs and whatnot and understand the workings of suspension. I wouldn't think the bar being stock with it lowered would give you that feeling of a shift that much.
On my two hour ride home after picking up my new car, I noticed over uneven bumps or road that the car shifted with no steering input. Kind of disconcerning. Then I remembered this chassis uses a PHB and this car is lowered a lot. Idk how much exactly but all I know is that they're Eibach springs, with a stock PHB. Maybe you guys can judge by the pic? The tires seem to be aligned with the fenders, but I haven't done a finger test to see, but now I know that doesn't really matter.
I know all about trig and arcs and whatnot and understand the workings of suspension. I wouldn't think the bar being stock with it lowered would give you that feeling of a shift that much.
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