Syclone 1992




Taking this toy out to play

“It’s not fair to let trucks that blow away cars come out to play;” – a mumbled greeting as I left-footed the parking brake behind garage #6 at Mid Ohio Raceway. Beneath my right Reebok was the slender pedal controlling nearly elemental force. 280 horsepower, 350 pounds feet of torque, 4.3 liters of turbocharged, intercooled, port fuel injected V-6 thunder, that fierceness coupled to an advanced all-wheel drive system. Blacker than Alaskan nightfall with a chassis slammed to within 6.25 inches of the track surface, this could only be the GMC Syclone, the most coveted truck in America.

Taking a pickup to a high performance driving school sure invited a lot of barbed comments, sidewise stares, lurid remarks made just out of easy hearing, and ultimately, lots of red faces. After 200 miles of tire-abusing, brake-welding, foot-to-the-floorboard performance testing we’ve reached some red hot opinions and smoking conclusions about the Syclone – with a simple and hard rock bottom line. If you want stunning performance in a pickup truck, there is no substitute.

“I’m so sorry I held you up, I had no idea of “that vehicle’s” performance,” said the delightfully female Lotus driver. Ah, the truthful words of the innocent. If you’ve acquired a Syclone you’re exploring new territory, encountering vistas once inhabited only by exotic sports cars. You should learn to drive this vehicle before it drives you. So we did. Went to school, that is. Me and the Syclone, mano a’ mano, up the tail pipes of lesser sporty cars like BMW, Lotus, Nissan 280 and 300, Taurus SHO, and other banzai runners.

For our story on the 1992 Syclone I picked up a two-door, two-seat, two-tone Lamp Black 1991 Syclone (there’s only a couple of ’92’s in existence and the engineers have ’em and proceeded to get some immediate impressions of GMC’s super truck. Cutting into rush hour traffic dramatized the enormous power smoldering beneath the hood. Zowie! 0- 60 in 5.5 seconds, according to our Vericom. First to second shifts from the Hydramatic 4L60 transmission are disconcerting; there’s just no way to elicit a smooth shift. Instead you feel a solid body slam with ultra-firm engagement to take Uj) the :350 pound feet of torque generated by the turbocharged, intercooled Vortec engine. Chassis feel immediately struck us as having overly stiff springs and slightly wimpy shocks, particularly on rebound. (In evaluating this platform it was ‘a constant struggle to remember the compromises. Syclone remains a pickup with a quarter-ton load capacity, not an exotic sports car.)

Motoring to dinner at the China Ruby in Ferndale, assaulted by the plentiful potholes and multifarious frost heaves of inner city Detroit, ride quality was similar to sports cars often-fifteen years ago: relatively smooth but plenty firm. We discovered something else from all the friendly waves, drooling glances, and heads-out-the-window conversation at every stop light – this is a popular truck.

Once on a smoother surface, the choppy motions of’ the Syclone settled out and became friendly as a lap dog. It was on that evening ride we began to discover inadequacies in the cockpit. First were the tiny analog gauges. They’re standard GMC Sonoma gauges in familiar size and location – small and hard to read without concentration. After a couple of weeks you’d get familiar enough to cope, even do a quick scan for a rough idea of what’s happening. But big enough to make a fast and accurate reading of, say the oil pressure gauge? Nope. Maybe that’s why there’s idiot lights. We found another nit to pick once the sun was down. Instrument panel dimming applies to the PRNDL gate as well. It’s illuminated like Tiger stadium and well within your peripheral vision: if you set the dimmer for the shift gate’s glare, you can t read the speedometer. If you adjust for a comfortable brightness of the tachometer, you have enough light for a bases-loaded home run down by your hip. Are we being harsh, picking on isolated and meaningless details? Not at all. Once the price tag heads out of the $10-15,000 range into the stratosphere of more than $27,000, hey, we expect perfection. These issues should have been dealt with pre-production when the cost of change is reasonable.

Living with the Syclone revealed it’s adaptable and amiable nature. It performed every task, chore, and service we wanted (Within the 00 pound payload capacity) willingly and without complaint. Only brutalizing the accelerator revealed the savage horsepower underneath. Around town everything worked to perfection; ABS brakes (the first and only full-time four-wheel ABS system for trucks,) recirculating ball steering that was both firm without being heavy, and linear in response, and standard creature comforts like the mega-decibel four-speaker Delco stereo ’92 adds a graphic equalizer! CD player, tilt wheel, lighted vanity visor mirrors, intermittent wipers, cruise control, tinted glass, power doorlocks, power windows, and always efficient air conditioning. The Lexxus TruxCover rear tonneau cover is a nifty standard feature that carries over. 1992 Syclones will also have dual remote outside rear view mirrors, carpeted floor mats, and exterior graphics will be slightly revised – like the GMC logo rendered in black, not red.

There are further cosmetic changes for 1992, besides the 2-tone black paint, Red, White, Teal Blue, and Aspen Blue will be offered this year, each with a lower gray panel to continue the theme.

Seats—racing style high back buckets trimmed in red, featuring Syclone logos look better than they fit. They lack lateral support commensurate with the cornering forces this truck is capable of. And lower spine support- Forget it. There is an inflatable lumbar support, but it doesn’t address the basic lack of structural foundation for your lower back, a back that is forced into a very upright posture good for driving but equally forced into an unnatural curve. Not only that, but there’s no rake adjustment. How bad was it? On my way to Mid Ohio I ended up buying a 1″ thick chair cushion to place behind my back and hold agony in abeyance. It worked fine.

Another concern, made worse by the seat’s missing lateral support, are the “roller blind” standard seat belts.

Belts that conform to safety standards generally offer restraint only upon impact. Driving this most excellent truck at anything like it’s limits demands your butt be anchored tightly to the seat at all times – and chinchable belts are available in Corvettes via TRW. A simple “cinch” button on the ‘Vette belt retractor mechanism locks it solidly, then by moving the seat up a notch you achieve effective bondage. For driving school we put in a set of four point belts, but seat design prevented us from using the shoulder belts, so we used the 3″ lap belt and standard equipment belt.

Arriving at MidOhio, we teched the Syclone with a Track Time inspector. Wheels and tires were checked, lug nut torque certified, brakes and steering and indicator lights confirmed.

Our first day began with a description of what to expect from a school oriented to high performance driving, not racing (although there are many similarities.) After a brief orientation, tire pressures were elevated (ours to LF-45# others at 40#), helmets inspected, and those of us with experience were introduced to our instructors. Novice drivers went to the classroom.

My instructor was Dean Haugharthy, from Medina, OH. Most of the time he’s a foreman for Industrial Combustion. But after 20 years of competitive driving in just about anything with wheels, Dean is entering his fifth year of Track Time instruction. We belted in, checked the gauges and burbled off to the tune of 280 port injected horsepower.

Both of us had concerns. Mine not to appear a fool, his to continue life. We agreed to concentrate on smoothness, braking, and generally feeling out what was to both of us a new high performance vehicle, especially one with all wheel drive.

After a few laps for familiarization with the rebuilt and widened Mid Ohio course, we were served up some interesting observations. First was how pleasantly easy the Syclone was to drive quickly. With 63% of its weight on the front wheels wed expected pronounced understeer. Torque, delivered to all four wheels through a Borg Warner viscous coupled transfer case, (split 35% front, 65% directed to the rear wheels through a 3.42:1 limited slip mechanical differential), contributes significantly to predictable handling. Unfortunately, while the truck turned in easily, unwinding from a full-drift tire-shrieking turn (and lesser maneuvers) requires micrometric precision and smoothness. Otherwise the chassis ‘jumps,” or lurches, making your steering input for any following turns, at best, an educated guess. Less spring and more dampening from the sport-calibrated Bilstein gas shocks would help, as would a stouter front anti-roll bar (currently 1.26) and the addition of a rear bar.

If you’ve never driven really fast, the importance of smoothness may be unfamiliar. It is vital on a race course and essential to finesse on the street, as well. A prime contributor to smoothness is making one dexterous input to the steering wheel for a turn, and one input only in most cases. Sawing at the wheel means the truck is driving you. Smoothness is one of the skills Track Time concentrates on teaching.

The second case, two inputs, is required to get a heavy, understeering vehicle through certain corners fast. That meant I had to learn to “toss” the truck, a foreign and antithetical concept. It requires a swift twist of the wheel, aiming the truck for a very early apex. The sudden (but smooth, remember?) violence of the maneuver unsettles the chassis causing all four wheels to begin sliding or “drifting”, and you quickly almost in the same motion—decrease steering input. The truck continues to slide in a controlled drift to the apex.

Why the toss? Too much front end weight and understeer was overloading a front tire, left or right depending on the turn. Upsetting the suspension allowed four tires to share in the cornering effort, not just one.

With handling characteristics somewhat sorted we began working on braking, quickly finding the binders unhappy with Track Time’s heavy demands. In retrospect I should have torn off both front wheels and inspected the entire system after the first session, we might have avoided some problems.

Slowing from 125 mph on MidOhio’s main back straight was no problem the first time. And recovery provided by 11.86″ ventilated discs was rapid. But I never gained real confidence for that critical braking maneuver and seldom achieved top speed on the straights, settling for “only” 115 and earlier, lighter, braking. One element of my fear was the typical slightly “mushy” feel of vacuum assisted brakes, a portion due to the ABS system, and another factor the capacity of the brakes themselves.

For all but the hardest stops pedal feel was linear, and light application resulted in settling the chassis, not hitting the window as in over boosted systems. So the balance is fine. Rear brakes, 11.2- x 2.75- drums, never faded causing us to spin. But for truly world class braking this truck needs four wheel discs, preferably with multiple pistons, offering twice the capacity of the present system. On the street you should be Erie unless using the brakes repeatedly and hard.

As we gained confidence in the package we began to shift the transmission to utilize the awesome torque offered, quickly finding a gated shifter would be welcome. Under power, the chassis could be balanced to ease every cornering situation: lift throttle to aid in turn in, neutral to moderate acceleration during cornering for maximum equilibrium, and hammer-down for exiting the turn. Here the full-time four wheel drive system played to maximum advantage. We could pull out of corners like the dogs of Hell or Second Terminator were after us – max traction.

For 1992 the Syclone Engine Control Module has been revised. Changes advance the spark faster. The engine continues to run best on 94 octane fuel, but will now respond to 87 octane when necessary. This change is the result of a more sensitive knock sensor. Other changes to the advance curve serve to shorten turbo lag, also facilitated by a swifter opening of the L98 throttle body. A final tweak is to rearrange the internal sound baffling to quiet the interior while preserving an aggressive and free flowing exhaust note.

One thing we noticed, the chassis was extremely reactive to speed. By that I mean there was a fine line separating predictable behavior all the tolerances in suspension and tires squeezed tight

and working as anticipated and sloppy demeanor if corner entry was too slow allowing for more compliance. If you over brake or scrub off too much speed before turn in, the chassis responds quite differently, causing a deviation in the liner of 10-20 inches. That doesn’t sound like much, but it can really destroy your plans and ruin a fast lap. And the demarcation point is narrow, a difference of a couple of miles per hour. 

For 1992 some of the noted problems have been addressed with changed base calibrations for both toe and camber, changes you 1991 Syclone owners should take advantage of at your first alignment. It will enhance the overall “feel” of your truck. And if you’re an absolute hard core racer at heart or in reality, GMC Service Parts will have a high performance package of rear stabilizer bar and new front bushings available, too. (GMC’s Typhoon addresses the issue by using softer rear springs and a load leveling device along with a rear bar. This approach is being evaluated as a running change or later model year inclusion for Syclone.)

A good deal of the credit for our never-spin, never-sideways days on the track go to Firestone Firehawk S-X 245/-0/16″ tires mounted on 16 x 8″ cast aluminum wheels. Driving near the chassis limit of .80-.85 G lateral acceleration, we built up enough heat to do a little tire chunking, but raising the left front to 45 psi and lowering the others to 37# put things right. For 1992 the same tires, with a revised compound, continue. A bit harder for dry weather stick, they won out in GMC performance tests among 33 varieties from 5 manufacturers. 

The second day of class started at 8 a.m. We arrived early to bleed the brakes hoping to cure the mushy feeling. Again we should have pulled the wheels and really inspected the system, but the pads looked only 1/3-1/2 worn. After classroom instruction in more advanced techniques, like trail braking vs. straight line braking, left foot braking, different methods for chassis balance, we went back onto the track. The rbrakes
still didn’t feel right so we concentrated on developing smoothness and getting “the line-instead of driving point-to-point -apex marker cone to apex marker cone.” We continued to pass just about everything in sight. 

Between sessions we ran some 0-60 accelerations, just to see how accurate the factory claims are. Others have reported five second runs – and below. We found 60 miles per hour coming up in :05.44, and :06.66 if we shifted manually. (Timing via Vericom.)

After lunch critical maneuvers were taught; slalom skills, and threshold braking . Slalom (“S-ing” between equally spaced marker cones) emphasizes smoothness and proper turn-in, how to load and unload the chassis.  Threshold braking is a matter of braking to the point of lock-up, then a credit-card-slim pedal release, just enough to keep the brakes off lock. As the Syclone is equipped with ABS, I did 60-0 testing using both feet on the brake and reaching for the radiator. That must have finally “crispy-crittered” the brakes, though I didn’t feel it.

Unbeknownst to us, the right front  inner pad was binding a bit – probably  what had been causing the unsettled feel. Ultimately, hydraulic pressure -caused the pad to bend inwards and not release properly, wearing it down to steel, finally welding itself to the piston. But even as it was nearing this tragic situation, the brakes were hauling me down from 60 miles per hour in 121-141 feet, straight and stable! Quite an accomplishment, eh?

 The brakes finally gave out when I sent the Chief Instructor and head of the school, Jack Lane, out to drive for photos, failing at the end of the back straight, no less. “No brakes, right to the floorboard,” Jack told me. Then I walked around the garage to find a happy crew of volunteers putting out the fire. Fire?

Yep. After Jack parked it, hydraulic fluid escaped around the ruined brake piston and ignited on the glowing hot disk. Luckily it only singed a tire, thanks to lots of enthusiastic help. My day of driving was over.

We learned much in over 200 miles of on-track flat out driving and cornering. If you want the ultimate off-the-shelf performance truck, this is it. But it’s not perfect. Pushed to the extremes of “world class” performance its advertising claims offer and you’ll find the truck in definite need of refinements to shocks and anti-sway bars, not to mention more powerful brakes. It should get a better instrument panel and demands seating that matches its high performance intent. However, driven at less than ten-tenths, the Syclone will exceed your every whim with ease, swiftly demolishing the credibility of famous “marque” sports cars, and etching an unshakable grin on your face.