V8 boardmembers: At coffee today, during a discussion about "A" body upper/lower control arms, one old rodder opined that another way to control body roll would be to install a rear panhard bar. I do not recall seeing anyone or hearing of anyone using a panhard bar on our GM A bodies. Has anyone heard of this or seen this? If so, what kind of results could we expect? Is a panhard bar install possible (or practical) with our current upper/lower control arm setup? Thanks, Ed
No - a panhard bar attaches to the frame and the rear axle to control the axle's movement laterally (side to side). A panhard bar is not required on a GM A body because the upper control arms are splayed outward (that is, a V shape when viewed from above). This orientation controls the axle movement side to side. An "anti roll" bar, which attaches to the body/trunk floor and then to the rear axle would control body roll; or the traditional "sway bar" that attaches to the lower control arms. K
I have added a panhard bar to a GM A body, on one occasion, because I took those upper control arms and oriented them fore/aft (parallel when viewed from the top). Moving that rear attachment point outboard does, in fact, help with body roll for a flatter launch. The panhard bar was then added back in to control the axle's lateral movement. K
Keith: Thanks for the explanation. On your "conventional" A body cars, do you employ fixed or adjustable upper control arms? BTW, would you please give the tire and wheel sizes front and rear on the suspension photo? Thanks, Ed
a) These were unadjustable (production) arms. I did that primarily for two reasons (1) a more stock appearance (2) they don't need to be adjustable if you hit the pinion angle correctly in the first place (lol). Nothing wrong with adjustables if you can afford them and if you intend to make changes in that area. b) Yes, I can get the tire sizes for you but I'll have to check them when I get home. I can say it is unlikely the rears will fit any production vehicles you might have without significant rework (like a mini-tub). K
Yeah, Keith, those rear tires are beyond belief and way too big for conventional buick. Awe inspiring,though. When you get to it on the tire info... Is the Buick in your avatar your race car? What does it take to raise the front end like that...? lol
Actually, that is a '74 Chevelle. It's a 555 cu in Chevy big block, AFR aluminum heads, Dart intake with either a 950 Holley or a Dominator (depending on the class). TH400 trans, 8.5" rear with Mark Williams spools and axles. 10.5" Mickey Thompson slick. 3950 lbs, best ET is 10.001 @ 136 mph. K
Ok, here ya go: Fronts are a P235/70R15 on a 6" wide wheel. Rears shown are a 29.0x15.5-15 Mickey Thompson Sportsman Pro. They are roughly 13" wide on a 10" wide rim. For my car, there were no changes required to the body to run that tire (other than the usual "rolling of the fender lip"). I don't run those tires any more. I found I could get better traction with the (then) new M/T ET Street tire, so I have a set of 30x13.5-15s (roughly 11.5" wide) that I run now. For a slick, my class requires a M/T ET Drag 29.5x10.5-15, which is a true 10.5 tire. K
If you want a real panhard rod setup go here http://www.hotrodstohell.net/truckarm/truckarm_chevelle/truckarm_chevelle.htm I would have done this but never saw a good way to have a full length exhaust system.
Keith those are very respectable numbers for that tank of a chebby. I always liked that style. My bud growing up had a Laguna S3. We had some fun in that thing!!!!!!
