Having been straight-line guys for most of our car lives, building an open-road racer is a foray into the unknown. The front suspension on our '89 Diplomat cop car was shot and in need of a freshening up. A clean bill of health, issued before we begin the modifications, will enable this portly beast to handle well and remain stable at speed. Our goal to run the Nevada Open Road Challenge in May is quickly approaching, and a good tight suspension is paramount to our quest for speed.
The Diplomat has a very unique suspension. Unlike those we are accustomed to in our traditional A-, B-, and E-Body musclecars, our Dippy features a transverse torsion bar front end that is rather unique and a bit confusing for the uninitiated. Introduced in 1976 on the new Dodge Aspen and Plymouth Volare F-Bodies, the transverse torsion bar was also the suspension of choice for the M-Bodies, such as the Grand Fury and Diplomat. We contacted Just Suspensions for one of their complete front-end kits, and then contacted Koni for a set of shock absorbers. We dragged all the parts to Sleeper Suspension Development in La Verne, Califorinia, rolled up our sleeves, and dove in. The decision to use Sleeper's facilities to help with this project was made because of Jim Sleeper's vast experience building a variety of race cars for numerous types of racing. Later we'll add trick new Quickor sway bars, and incorporate a couple of other mods to help our Diplomat along on its quest for high-speed stability.
(above & below) Our Diplomat...
(above & below) Our Diplomat came equipped with a transverse torsion bar suspension.Ours looked a bit worse for the wear and was a bit sloppy especially atspeed, inducing a high pucker factor. We intend to cure our pursuitvehicle of this unwanted ill behavior.
Just Suspensions provided...
Just Suspensions provided us with this complete rebuild kit thatincluded upper and lower ball joints, upper and lower control armbushings, an idler arm, a pitman arm, tie-rod ends, upper and lower bumpstops, sway bar bushings, plus (not shown) all of the dust covers andhardware.
Jim Sleeper of Sleeper Suspension...
Jim Sleeper of Sleeper Suspension Development spec'd out the Koni shockabsorbers (PN 80-2660 front, PN 82-1255 rear) we ordered for ourhigh-speed cruiser. Our shock mounts would need modifying to use thesepieces, as Koni doesn't offer an off-the-shelf, high-performance shockfor this rather odd application. Not many people are buildingopen-road-race, late-'80s police cars for some unknown reason.
After we removed our front...
After we removed our front tires, we unbolted the tie rods, hung thebrake calipers out of the way (removing them would later require a brakebleeding), unbolted the torsion bars, and backed the adjusters all theway off to remove tension. Now disassembly is possible.