GM EFI’S Guide to the GMC Syclone and Typhoon


We Take a Closer Look at the GMC Syclone and Typhoon

If you’ve ever find yourself in the company of car guys who came of age in the late ‘80s-early ‘90s, you’ll most probably hear them utter the term “SyTy” at least once. No, these electronically fuel-injected modern day hot rodders are not referring to some shi-shi cocktail at the local Asian Fusion place-they’re referencing two of the fastest and baddest GM machines built in the past century.

Of course we are speaking of GMC’s all-wheel drive turbocharged light pickup truck and midsize SUV; the 1991 Syclone and 1992-’93 Typhoon.

Continuing to chronicle GM’s late model high-performance machines, we will cover GMC’s devious duo, documenting their origins, features, colors, performance stats, special editions and production totals… batten down the hatches!


GMC’s sinister siblings the Syclone and Typhoon trace their origins to the turbocharged tire-shredding Buick Grand National and Pontiac’s 20th-Anniversary Turbo Trans Am. Last built in 1987, Buicks G-body Regal Grand National had embraced the dark side of the force and while wielding it’s SFI 3.8L turbocharged V6, regularly vanquished pricier performance cars with more cylinders and greater pedigrees.

Two years after the GN left the marketplace, Buick stretched-out it’s hand to Pontiac, supplying the same howling hair dryer-equipped six-cylinder saber to commemorate the Trans Am’s 20th birthday. The job of preparing/fitting the special birds with Buick’s turbo powerplants and other performance upgrades such as 1LE brakes was given to Production Automotive Services (PAS) of Troy, Michigan.

Expanding-on the GN’s neck-jerking, butt-slamming straight-line acceleration, the Turbo TA’s handling and braking abilities further complimented the power of Buick’s legendary turbo-6.

By the time all 1,555 examples were built, the 20th-Anniversary Turbo Trans Am was anointed as one of the quickest American production cars to that point and the fastest Firebird Pontiac ever built. Even during the Turbo TAs run however, Buick was yearning to fit another platform with its famous turbo motor.

After experimenting with several of it’s own nameplates, even engaging in costly rear-drive conversions, the boys at Buick had an American epiphany of sorts. Why not take one of the best selling vehicle types in the country, and put our LC2 3.8L turbo in it? Running with that formula and fully aware of Americans affinity for trucks, Buick nabbed a Chevy S-10 and proceeded to turn the little mild-mannered Dr. Jekyll of a pick up, into a turbocharged Mr. Hyde.

Basically transforming the rear-drive S-10 into a light sport truck version of a Grand National, Buick crammed an LC2 3.8L turbo-six into it’s engine bay and adorned it with GN badges, wheels and styling cues, even a custom-fabricated bulged hood with “3.8L SFI Turbo” call outs on it. The final concept definitely looked the part, now all Buick had to do was sell it to the General.

Although the idea seemed like a home run to Buick, GM turned down the upscale division’s request to build the hot little pickup and refused to permit Chevy, (who’s S-10 was used for the concept) to do the same, because the “Bow Tie” already had their 454 SS in production.

Finally and appropriately enough, GMC, the Generals truck-maker was approached with the opportunity and quickly ran with the idea instilling changes/upgrades to the project, making it their own.

With that said, the chosen platform was now the S10-based Sonoma, basically the same as the S-10, but with “GMC” donning the grille. Because fitting Buick’s 3.8L V6 to the Sonoma’s engine bay required costly modifications for assembly-line installation, the LB4 4.3L iron block/head Vortec V6 already in use in the Sonoma was used instead. On top of the powerplant and appearance features, GMCs new performance truck would offer 4-wheel antilock brakes and full-time all-wheel-drive, definitely exotic features for the day (especially for a pickup).SYTYGUIDE-26

Following-up their work on the already legendary ’89 Turbo TA, the task of developing the Syclone from concept to production was again given to Production Automotive Services (PAS) of Troy Michigan.

With concept versions, (originally shown in all white with red graphics) making the rounds during the 1989 International Auto Show Circuit and at SEMA, the Syclone received much fanfare and an enthusiastic response.

As the final version was nailed down (and changed to all-black) the Syclone was slated as a 1991 model with production commencing early in the year at GMC’s Shreveport, La assembly plant. To address the unique spelling, Ford’s Mercury division still held rights to the “Cyclone” name used on their muscle car some twenty years earlier.

With final reports confirming the news, the barometer began to drop, the sky turned gray and the wind howled in anticipation of the coming storm…take cover.


Rarely do production vehicles outshine their concepts, but in the Syclone’s case, it was obvious that GMC/PAS had done their homework in presenting a well tuned, balanced and purpose-built high-performance machine.


Paying some homage to the Grand National, all 1991 GMC Syclones came cloaked in badass black with an aerodynamic monochromatic ground effects package including a large front fascia/air dam extension with integrated driving/fog lights. Carrying the sinister (don’t mess with this) look even further, is a unique red-colored “GMC” grille and tailgate emblem and red “Syclone” decals on the doors and left rear tailgate.

Perhaps no other visual feature separates the Syclone from its Sonoma roots as much as it’s rolling stock. In support of the immense power on hand the Syclone rides on 16×8-inch turbine-style aluminum wheels (with red “GMC” center caps) wrapped in 245/50R16 all-season performance Firestone tires. Even when stationary, the turbine wheels portray speed.

And not to forget the Syclone’s pick up truck designation, even though load capacity was un-truck-like at only 500 lbs — a unique black vinyl tonneau cover mounted on an adjustable frame with stainless steel fasteners was included. Definitely presenting a mean streak by appearance, what lurked beneath the black sheet metal is what really built its reputation.

All Syclones were identically equipped with the port fuel-injected LB4 4.3L Vortec V6, dressed with a Mitsubishi TD06-17C/8cm (RH06) turbocharger and Garrett water-to-air-type intercooler with integral waste gate and heat extractor all capable of 14-psi. of boost.

Further beefing things up were unique low-compression (8.35:1) cast pistons, stronger main caps, specific intake/exhaust manifolds to better work with the turbocharger unit, a unique straight-trough exhaust system, heavy-duty oil cooler, improved fuel system and a 48mm twin-port throttle body from the 5.7L L98 C4 Corvette engine.


Standard in all Syclones was the C4 Corvette-sourced 4L60 4-speed automatic transmission with a special performance-shift calibration, wielded by a leather-wrapped shifter that was also sourced from the Vette. Carrying the power of forced-induction to the ground was a BorgWarner full-time all-wheel drive system with a transfer case that split the torque output between the front axle at 35% and the limited-slip rear differential with 3.42 gears at 65%.

Sitting squat to the pavement with only 6.25-inches of ground clearance, the Syclones tough street-fighter stance and sports car handling is accomplished by a lowered ride height and sport-calibrated suspension featuring independent torsion bars and stabilizer bar with tuned Bilstein gas shocks up front and a solid axle with semi-elliptical 2-stage leaf springs and Bilstein shocks out back.

As promised the Syclone was the first pick up ever to come equipped with four-wheel antilock brakes (ABS), which applied stopping control to power front discs/rear drums. Despite the old-tech leaf springs and wide-patch rubber, the Syclone’s ride was marked as surprisingly smooth.


All this hardware equated to a level of performance that was astounding for 1991 and quite frankly, still astounding today. Power output was an underrated 280hp and 360 lb-ft., a 30-horse advantage on the standard L98-powered Vette of the day.

With all four steamroller-size wheels launching the 3600-lb. pickup forward like an F-14 Tomcat fighter being catapulted from an Aircraft Carriers deck, the Syclone could rip low 4-second 0-60mph sprints and run mid-13s in the quarter at over 100mph and get 17/24mpg (city/highway).

These stats weren’t just superior to a run-of-the-mill C4 Vette, but equal too or better than the all-powerful 375hp LT5 ZR1 in both dry and wet conditions-oh, and umm, for less than half the price. Not to be redundant, but Italy’s finest also felt the Syclone’s wrath, as noted in the ever famous and highly touted Sept ‘91 Car And Driver comparison article.SYTYGUIDE-11

Despite putting-up lower than manufacturers numbers, the $25-thosand dollar hotdog of a pick up beat a $122,000 parmesan-powered Ferrari 348 in most performance categories including 0-60, 1/4-mile time and braking distance. Top speed went to the Italian stallion however, galloping to 160mph, while the Syclone was governed to a Category-4 speed of 124mph.

The (ZR9) Syclone AWD High-Performance Package didn’t just net you a turbocharged pick up truck with ridiculous performance and a mean black paint job, it included just about every power comfort/convenience feature available.

Standard accoutrements filling the Syclone’s cab include:

  • AC with deluxe heater/defogger and LH/RH window defoggers
  • Power windows/door locks
  • Leather-wrapped tilt steering wheel
  • Cruise control
  • Unique analog gauge cluster, with tachometer, 120mph-speedo, turbo boost, oil pressure, coolant, odometer/trip, fuel level, voltmeter and engine temp gauges (gauge cluster is a modified version from the 1990 Pontiac Sunbird Turbo)
  • Unique recontoured front bucket seats with manual lumbar support in dark charcoal cloth with red piping and red-embroidered “Syclone” on headrests and matching door panels and floor mats
  • Electronically tuned AM/FM stereo with seek/scan, cassette tape, digital clock, front/rear speakers with mast antenna (Premium stereo with graphic equalizer-optional)
  • Tinted glass
  • Interior lighting package
  • Unique center console with storage space and cup holders
  • Red “Syclone” emblem on glove box with door-activated light


In total, 2998 Syclones were built, with 2995 being ‘91 models and only 3 supposedly slated for ‘92, before cancellation. According to a GM press release, some upgrades were scheduled for the ’92 Syclone, they included:

New computerized engine calibration to provide better performance with lower octane fuels, smoother turbo boost, enhanced drivability and reduced engine noise
Dual remote outside rearview mirrors and carpeted floor mats, now standard equipment
Four new available exterior paint colors, Red, White, Aspen Blue and Teal-each with Gray lower body moldings (Black/Black still available)
As for the engine/drive train, GMC obviously thought, “if it ain’t broke don’t fix it” and if your able to smoke a Vette or Ferrari, why would you.


Nicotine Rush: Marlboro Syclone

Back in an era, before the majority of rational-thinking Americans accepted the dark truth that cigarettes caused cancer and smoking them would probably lead to a slow and agonizing death; mega-companies like Phillip Morris/Marlboro, held great power and influence, especially in the world of auto racing sponsorship, i.e., NASCAR’S “Winston” Cup series.

That said, as part of a 1991 promotional campaign, Marlboro teamed with Larry Shinoda, (who designed the ’63 Corvette Stingray and ’69-’70 Boss Mustang) to customize and give away ten special Red Corvettes wearing Marlboro-themed white strobe-stripes, a unique body kit, special wheels and red leather interior.


With over three-million entries from yellow finger-tipped Vette fans, Marlboro was ecstatic with the response and eager to repeat the effort. Giving new meaning to the adage, “smoke ‘em if you got ‘em,” the great cigg-maker sought the already press-prolific GMC Syclone for it’s next smoking contest vehicle give-away the following year.

Once again, Shinoda Design Associates was called upon to handle the overall design elements and ASC (American Sunroof Corporation) was tasked with the actual transformation/customization.SYTYGUIDE-12

Technically a 1992 affair, ten Syclones were plucked from the ‘91s built, with winners announced and given their trucks in Sept ’92. Word has it, all ten Marlboro Syclones still exist to this day.

The Conversion was extensive and included:

  • PPG “Hot Licks” red paint with Graphik Concepts white strobe stripes on hood and doors and white “Syclone” decals
  • Targa T-top-style roof conversion with custom roof panel storage mounts in pick up bed
  • Lockable Guidon tonneau cover
  • Slide down/retractable rear window assembly
  • Recaro leather seats with Simpson 5-point harness
  • MOMO leather–wrapped steering wheel
  • PROMpak performance computer and Borla S/S exhaust system
  • BellTech suspension with 3-inch drop
  • Boyd Coddington billet wheels with black-painted centers, polished lips and “Marlboro” logo on center caps, with Goodyear Eagle GS-C
  • Sony sound system with CD

Indy Syclone:

Chosen for the twelfth time as official truck for the Indianapolis 500, GMC would further capitalize on the appeal of its new niche vehicle, providing three Syclones for the 76th running of the great race. With no modifications necessary other than Indy 500 decals (much like the ’89 Turbo Trans Am that came before it), the Syclones were used as quick accident response vehicles and drew countless gawks while on display.


One of the Indy Syclones was converted to the PPG paint Syclone Pace Truck — although this title was just that, as Cadillac’s Allante was the actual official pace car. The one-of-one PPG Syclone displayed a multi-colored paint scheme, showcasing the array of proposed available colors for the ’92 Syclone and the upcoming Typhoon.

Other modifications included:

  • Special-tuned suspension
  • Special modified water-cooled front brakes
  • Racing fuel cell
  • Fire suppression system
  • Custom-painted hard tonneau cover
  • Custom-molded roof skin with integrated lights
  • Strobe/crowd control sirens

After living in the GM Heritage collection, the General’s financial woes led this super rare Syclone to the block at Barrett Jackson
in 2009 where it fetched 60k with a scrap-title and non street-drive status. According to an anonymous Internet page, the PPG SY changed hands again in 2013, going to a private collector.

Little Oil Rigs: The “Saudi Syclones”

Viewing the car collections of most Saudi princes back in 1991, an assortment of fine Italian exotics, precision German machines and classic British marks would probably make up the lions share. It’s fair to assume however, that not one boosted 280-horse, all black, all-wheel drive; all-American pick up truck would be part of the lot.

That being said, multiple sources document the allotment of 150 Syclones slated for export, with 113 of these sand stormers making their way to the middle east, specifically Saudi Arabia. Identical exterior-wise to U.S. models, the Saudi Syclones did have necessary changes for their new environment.


Much of the dash was carried over from standard S-series trucks, but the Sy/Tys sourced their gauge clusters from the Pontiac Sunbird GT Turbo, of all places. However, the gauge cluster found in the “Saudi Syclones” were in Metric, per KSA regulations.


All Saudi Sy’s got metric gauge clusters like those fitted to units going to Canada. These clusters were devoid of turbo boost and rev counter gauges and had no low turbo coolant lamp.

In 1991 Saudi Arabia used predominantly leaded fuel, therefore, Saudi Syclones had no need of their O2 sensors/catalytic converter, which was ditched and replaced by a straight pipe–style resonator. A new leaded fuel chip was also installed to communicate this to the computer.

After seeing limited interest and low sales like their American counterparts, 1994 saw 100 or so, Saudi Syclones removed from Saudi Arabia, with 31 returning to the new world and 69 eventually sold throughout Europe.

Upon return, supposedly 30 units (1 was used for parts) had their emissions stuff converted back to U.S. specs at a GM facility in Pontiac Michigan, covered by a 3 yr/36,000mile warranty (except paint) and sold via lottery to only GMC employees, (those who knew about it) for only, an alleged $12,500 each.

Celebrity Syclone:

Former Tonight show host and renowned car collector Jay Leno bought a Syclone when new back in 1991. Using the little black truck as his daily driver, the car guy/comedian dusted his share of LA exotics, whose owners probably didn’t find it very funny at all.SYTYGUIDE-5

On a recent episode of Jay Leno’s Garage, Jay gave a look and test drive of his 25 year-old Syclone, during which he divulges that his has a few GM secret mods that make it a bit faster than normal. Jay says with regular maintenance, the truck is pretty bulletproof, fun to drive and will always hold a place in his collection. A better endorsement, there isn’t.

GMC had hoped to sell 10,00 Syclones in 1991, but with only a third of that goal achieved, the ’92 Syclone was cancelled before the winds even began to “pick-up.” Not to worry though, the General had another storm brewing already.



With the Syclone’s winds calming down as quickly as they came, a new storm truck called Typhoon was already blowing into GMC dealerships early in ’92. Jumping on the emerging Sport-Utility bandwagon, the (Z79) Typhoon was based on the GMC Jimmy 3-door mid-size SUV. Advertised as “the sports coupe of sports utilities” GMC’s SUV was a very different animal.

Once again transformed by PAS Production Automotive Services, the Typhoon got the same awesome engine/drive train as the Syclone still making 280-horses, but seemed to get an additional-stated 10-lbs of torque, now rated at 360 lb-ft.

Also unique to the Typhoons arsenal, an electronic air-operated self-leveling rear suspension that balanced the heftier trucks 3800+lbs and provided a smoother ride.


Besides the obvious addition of a rear seat and bed covering/roof, the Jimmy-based Typhoon had a shorter wheelbase, overall length dimensions and slightly increased width, making it the better handler of the boosted brothers. Appearance features were almost identical to the Syclone, with the only real difference being Gray “Typhoon” and “GMC TRUCK” decals/badges on doors, tailgate and wheel center caps, instead of the Syclone’s red. Only the “GMC” grille badge and “Typhoon” glove box emblem remained blood-colored.SYTYGUIDE-19

Following GMC’s ad campaign “If you have settled ideas of luxury, safety and performance, a Typhoon will blow them away.” The $29,470 MSRP offered a more balanced and contemporary ride than the Syclone.

All Typhoon interiors were fitted with everything the Syclone had plus, leather seats with adjustable lumber support via hand-pump bulbs, dual electric remote outside mirrors, AM/FM stereo radio with graphic equalizer (CD optional), a remote Keyless entry system and 67.3 cubic ft of luggage space with the rear leather bench seat folded down.

The Typhoon could also haul 900-lbs. of stuff if need be, 400-lbs. more than it’s pick-up predecessor. However, performance took a slight hit because of the extra poundage, with the Typhoon hitting 60mph in the mid 5s and the 1/4-mile in the low-14s, but of course the LB4 turbo-6 can be tuned/upgraded seven ways till Sunday, making up for the weight differential.

As mentioned, the cancelled ’92 Syclone was to be available in a rainbow of colors, but now the Typhoon wore the new hues.

For ’92 the Typhoons color chart included:

  • Midnight Black
  • Frost White
  • Aspen Blue
  • Bright Teal
  • Forrest Green Metallic
  • Apple Red

Two experimental colors, Raspberry Red Metallic and Radar Blue are included in the ’92 color totals, with only 2 of each built, both with body-color ground effects. For ’92, the Typhoon was available in its signature Black/Black color scheme or for an additional $172; RPO BYB could be applied, pairing Gray body appliqué/ground effects to the black truck. All other available colors for ’92 came with Gray appliqué/ground effects as standard.

Optional on ’92 Typhoons was $126 RPO V54 painted roof-mounted luggage carrier (rack).

For 1993, Bright Teal and Aspen Blue were off the chart and the experiment with Raspberry Red remained just that, as no ’93 Typhoons were covered in that color. New for ’93 were Garnet Red and *Royal Blue Metallic- which Included one Radar Blue/Radar Blue unit in the total.

Also for ’93, Black, Red and White Typhoons could get body-color appliqué/ground effects, while all other colors had standard Gray appliqué/ground effects.


Typhoon Tidbits: Notables

  • Resulting from the abundance of engines originally slated for the ’91-’92 Syclone, all Typhoons got the same LB4 motor with “Syclone 4.3 Turbo” embossed on top of the intake manifold
  • The ’92 Typhoons had plastic door handle shields, while ‘93s did not
  • The logos on ’92 Typhoons are only grey or gold on ‘93s
  • Interior door panels on ’92 Typhoons have a pleated pattern, while ‘93s have a non-pleated horizontal seam
  • Front/rear seats in ’92 Typhoons had leather surfaces with cloth sides/backs, manual adjustable lumbar support via hand-pump bulbs and “Typhoon logo in headrest, while ‘93s got full leather power front seats
  • Along with six prototypes, 4,697 Typhoons were built in total, 2,497 for ’92 and another 2,200 in 1993. Although they sold a little better than the Syclone, the numbers still didn’t equate to a long production run, as 1993 would ultimately be the final year.


Although brief, no SyTy history would be complete without mention of the ’92 Sonoma GT.

Completing GMC’s sport truck trifecta, the Sonoma GT was built for ’92 only and slated as an affordable alternative to the Syclone/Typhoon. Also modified by PAS, the $16,770 Sonoma GT featured most of the Syclone’s interior and exterior visual accoutrements including body appliqué/ground effects, unique red badging, gauges, seats, etc, but was powered by the naturally-aspirated 195hp L35 central-port fuel-injected Vortec V6.


Rear-drive and devoid of turbocharging, the Sonoma GT still had stout performance, shifted via the 4L60 4-speed automatic with a limited-slip rear diff/3.42 gears, a tuned suspension and power front discs with ABS assisted rear drum brakes.

The Sonoma GT was more of a real pick up than it’s boosted brethren, with a 950-lb. load capacity and 5000 lb towing capability. Available in the same colors as the ’92 Typhoon, only 806 Sonoma GTs were built, making it rare as well as under-appreciated. Unfortunately for PAS Production Automotive Services, the end of GMC’s niche truck line led to them closing-up shop by 1994.


With only 7695 examples built over just three model years, collectively, the GMC Syclone and Typhoon’s reputation exceeds their numbers and production run by leaps and bounds. Taking full advantage of an opportunity to compliment the General, the SyTy trucks are a perfect example of GM’s creativity and engineering prowess at a time when American performance was still hovering around adequate.

Not since Ford’s great GT40 LeMans race cars, had an American machine put such a whooping on Ferrari’s “Prancing Horse,” and from a streetcar, that’s an accolade that cannot be overlooked. Although other makes both foreign and domestic have unleashed comparable high-performance pick ups and SUVs, none have had the spooling sensation or left the swath of embarrassed exotics like the GMC Syclone and Typhoon.

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