Today’s Truck and SUV Performance
When the GMC Typhoon it the market, it generated more than its fair hare of excitement. But, like its tropical storm namesake, its intensity was not long lasted and the adrenaline-inducing truck was discontinued after the 1993 model run. Much to the chagrin of performance truck enthusiasts, the limited-production status of the Typhoon made retooling the thoroughbred for the then-upcoming 1994 restyle fiscally impossible. The truck was, and still is, a performance icon with 0-60 performance in the 5.4- to 5.6-second arena and quarter miles flashing by in 14.3 seconds with trap speeds in excess of 95 mph. All this from a 4.3-liter-turbochargecl V6 rated at 285 horsepower at 4400 rpm and 360 lbs-ft of torque at 3600 rpm and a high-tech, all-wheel drive powertrain. The Typhoon relies on a 4L60 four-speed automatic and BorgWarner 4472 all-wheel-drive transfer case with viscous coupling to deliver sure-footed traction any time anywhere. This is accomplished by directing 35 percent of the power to the front wheels and 65 percent to the rears. When traction is lost by a wheel, the viscous coupling transfers power to those wheels with the best grip. During the road test of a stocker in ’93, we generated 1.1 gs at launch-a testament to the bite of the AWD system. For us, one of the hardest things to live with when looking back at the Typhoon is that the price tag of this road rocket was in the $28k range, about the price of an XLT-trim Ford Explorer today.
Suspension
One of the aspects of the Typhoon that Chevy struggled with throughout the truck’s production run was the rear suspension. It got a few tweaks for ’92 and a healthy massaging in ’93. The rear suspension features a two-stage semi-elliptic multi-leaf spring set-up with electronic load leveling shocks and integral air bags. While the revised spring rates and reworked shock valving of ’93 were a definite improvement, they left a bit to be desired. There seemed to be too many components out back with some of them working against each other rather than as a team.
This white ’93 represents the next step in the evolution of the Typhoon rear suspension. The GMC runs a pair of Air Lift air bags that are positioned outboard compared to the factory set-up. Positioning the bags outboard makes the truck more stable by limiting the chassis’ tendency to roll. Air Lift’s Double Duty suspension uses fiberglass leaf springs which really help the cause by decreasing unsprung weight by about 45 pounds while lowering the truck 1-3/4 inches. A set of Tokico performance shocks help smooth out the road and absorb suspension impacts.
Engine
The muscular 4.3-liter engine was pumped up further with a Fresh Air Package from Kenne Bell. The Fresh Air kit is a 50-state legal affair that directs a cooler charge air through a high-performance K&N air filter and into the turbo faster than with the stock set-up. Installation encompasses removing the stock filter assembly and plumbing and mounting a new coolant recovery tank in its place. As an added feature, the battery remains in the s tock location. The Kenne Bell package delivers a very noticeable 25-horse improvement in output. To keep fuel needs met a Kenne Bell fuel pressure regulator is on duty providing 52 psi to the fuel rail. Also part of the performance equation is a complete stainless- steel exhaust system from Borla Performance. The Borla set-up consists of three-inch stain less-steel tubing and a performance muffler. To keep the 4.3-liter purring, Texaco Havoline synthetic oil is used religiously. A Hayden oil cooler has reportedly lowered operating temperatures by 25 degrees. Heat is the arch enemy in the under-hood environment of a turbocharged vehicle. A trio of dash-mounted VDO gauges keep track of boost level, engine oil temperature and transmission temperature.
Driveline
A Hayden auxiliary transmission cooler helps the Art Carr-modified 4L60 cope with the heat stresses generated by the GMC. Art Carr installed one of its HP Target converters as well as a valve body kit and clutch lock which allows the torque converter to be locked and unlocked at will.
Going with the billet enthusiasm look, a set of trick Boyds fives poke aluminum wheels were selected to set the GMC apart from the crowd. The Boyds are wrapped with Goodyear Eagle RS-A performance rubber of the 225/60R-16 variety. Looking behind the Boyds we find yet another awe-inspiring component package- big, beefy, race-bred brakes. The Typhoon runs Baer Racing’s Baer Claw performance b rakes at the corners. The stock four disc set-up has been replaced with 12-inch cross-drilled and ventilated rotors and two-piston PBR pad-guided design (floating) calipers in front. The rear utilizes 12-inch drilled rotors and one-piston PBR calipers. The Baer binders have proven their mettle on the track in the company’s SSCA World Challenge Mustang road racers and are quite at home on a truck with the performance prowess of the Typhoon.
Impressions & Performance
The blinding speed and the audacity of a turbocharged, all-wheel drive SUV have made the Typhoon a bit of a cult classic. Many who own these trucks are into speed and there are a number of performance companies catering to the GMC Typhoon/Syclone line of trucks. It was these two points that convinced Gary Bryson to spearhead this project. He is one of the aforementioned thrill seekers and part owner of the PR firm Bryson, Cole & Company which represents a good deal of the companies who have embraced the Typhoon.
On the road, the improvement in the rear suspension is noticeable as the chop has been reduced. However the truck does tend to get on the air bags a little quick and jar the passenger compartment. Gary plans on changing springs which will raise the ride height and add about 3/4 of an inch in suspension travel which should cure the problem. We noticed that impacts at moderate speeds (40 mph) seemed to emphasize the jarring. At freeway speeds where one would think the effect would be magnified, the truck rode surprisingly well.
