As we discussed last issue, our mission with the newly acquired '83 T-type is simple: Prove that the aging G-body platform can handle some serious turns. The first step was to pull the rusting body and frame apart, and make sure we had a solid foundation to build. Thankfully Dave Rushen and the students at the Burlington County Institute of Technology had their work cut out for them. Using a host of Summit Racing products, the crew restored our rusty frame and even welded up a few of the problem areas. This meant that it was time to reveal the star of the show, our Detroit Speed Inc suspension.
G-Machine moguls Kyle and Stacy Tucker were all too happy to provide Detroit Speed's front and rear Speed Kit. The front kit (PN 031333) is a complete setup of control arms, shocks, springs, chassis braces and an anti-roll bar. Starting with the control arms, Detroit Speed uses Delrin bushings to prevent deflection and give consistent handling. Positive caster (more than factory) is built into the lower control arms as well as heavy-duty sway bar endlinks. The upper arms are particularly trick, using DSE's "Caster Tuner Bushings" to adjust caster without using shims, while also being very precise and permanent. The improved geometry of the design should also help increase static camber (camber gain) and improve roll camber (changed due to body roll). Finite Element Analysis (FEA) was used to model these arms and ensure strength, which lead to CNC machined tube ends and billet ball joint pockets as well as CNC stainless steel cross shafts. Meanwhile, the spring and shock design is quite a bit simpler. The two work in concert with the 1-3/8-inch hollow sway bar to provide a 2-inch drop with optimized rebound, compression, and spring rates. And the chassis braces tie it all together by triangulating the front crossmember and frame rail with 1-1/8-inch x .120-inch wall DOM.
With the heavy-duty front-end components ready to dig a sticky set of rubber into the pavement, DSE's rear Speed Kit (PN 043110) would help balance the Buick to induce some "controlled slides." Since the G-body has a traditional four-link style rear suspension, upgrades are fairly simple--upper and lower control arms, sway bar, springs, and shocks. However, that is not to say that designing said parts properly does not require plenty of attention to detail. One of the nicest features of DSE's rear control arms is that they use patented Swivel-Links instead of spherical rod ends, which allow you to run a very sticky tire with no binding and full articulation yet low on noise. Adjustment to pinion angle for improved traction is also very easy. DSE's economical rear shocks, just like the front, provide modern valving technology that will help keep the tires firmly planted. Double adjustable coilovers (front and rear) are also available for greater control, and easy adjustments to ride height. However, our setup used the more traditional style 2-inch drop springs, which come with two urethane jounce bumpers, to interact with DSE's adjustable sway bar. The rear sway bar is available in different thicknesses depending on use and driving style. We went with the larger 1-1/8-inch bar, made out of 520 DOM, that provides 1,084 lb/in or 1,422 lb/in depending on which of the two holes you use. The sway bar mounts to the chassis using more Swivel-Links, as well as the rear end housing, instead of the lower control arms (like factory) to minimize deflection.
Just like last time, the DSE components will be installed by the students at the Burlington County Institute of Technology in Medford, New Jersey. Lead by their teachers George D. Rushen, Anthony Mariano and Larry Melrose our G-Machine project is a [rusty] tool for achieving a NATEF certificate and valuable experience for an automotive career. Follow along as the next generation of gearheads overhaul and update the chassis on our '83 T-type project car as we prepare for a life of high-G turns.