There has been a lot of talk regarding the GNX suspension sold by Kirban Performance Products. From what we have seen, a love-it-or-hate-it attitude exists regarding this system. The hard-core racers scoff at the idea of spending so much money (A complete kit with an exhaust system is $2545.) for a reproduction suspension piece when a race rear swaybar or adjustable control arms would provide similar traction enhancements for less cash. The collectors are crazy about the idea of the GNX-like exclusivity and improved street performance from the ladder bar/torque arm setup. We at GMHTP like to ride the fence. We're always looking for a few extra tenths here and there, but our cars are our daily (and sometimes our only) transportation, so reliability and OEM-style engineering takes precedence over ET reduction. We hear pretty much what you hear, that this system is supposedly the real deal, so you can see why we've had our eyes on it ever since its introduction in 2000. After a few conversations with KPP owner Dennis Kirban, we learned that the gentleman who undertook this project (a fellow GN and GNX owner) spared no expense in accurately recreating the suspension responsible for the GNX's blistering 0-60 and quarter-mile times back in 1987. For people who try to put as many street miles on their cars as possible, we couldn't see a downside to this system--provided it lived up to its billing. Once we ordered it, we put in a call to Cotton's Performance Center regarding the installation. Jack Cotton is well-versed in turbo Buick restoration and performance, and has fabricated every square inch of his 9-second T-Type himself, so we knew we'd be in good hands.
Our test mule was a daily-driven 152,000-mile Turbo-T. This old warhorse was basically stock until the fuel system took a dump at 100,000 miles. Now it sports a few minor modifications, such as green stripe injectors, an adjustable fuel pressure regulator, a Bosch inline fuel pump, a high-flow air filter, and a 3-inch downpipe/dump tube that we snagged for $100 off the Internet. With nothing more than a Red Armstrong 108 race chip, good gas and a cooled intake, it spun its way to a 12.94 ET on ET Streets and a Vericom-recorded 4.99-second 0-60 time on real radials at Englishtown, New Jersey's Raceway Park. Traction aids were ripped (read: uninflated) airbags, SouthSide Machine lift bars, a pinion snubber, and a flaring, downtrodden stock transmission.
Our goals are simple: We're going to run this system over the coals and see how well it holds up. Launch it hard on slicks and street radials and compare the timeslips. Hang the tail out in fast corners and wait for it to break loose. Report any change to the car's ride characteristics, good or bad. And listen for the sounds that ill-fitting suspension parts and exhaust systems make. But first let's tackle the install, quoted by Kirban Performance Products to take four to five hours under normal conditions.