1987–1992 Pontiac Firebird / Trans Am GTA (3rd Gen)
Historical context and development background
The third-generation Firebird arrived for 1982 as a clean-sheet, wind-tunnel-shaped F-body on a diet. Lighter, lower, and much more aerodynamic than the second-gen car, it was the right platform for Pontiac’s upmarket Trans Am GTA, introduced for 1987. GTA—Grand Touring Americain—was conceived as the grand-touring apex of the Firebird range: the torque-rich Tuned Port Injection (TPI) V8 from GM’s small-block family, mated to the WS6 chassis package, four-wheel disc brakes on most builds, and the now-iconic 16-inch crosslace wheels shod in 245/50VR-16 rubber.
Corporate reality shaped the spec: Pontiac tapped the shared F-body architecture and leveraged GM’s parts bin brilliantly—Corvette’s L98 5.7L TPI V8 was made available (automatic only), while the lighter 5.0L LB9 TPI could be had with the Borg-Warner T5 five-speed. Styling retained the third-gen’s crisply chamfered surfaces, while the GTA added body-color aero skirts, specific badging, and a richer interior. By 1991 the nose, rear bumper, and cladding were updated for a cleaner, more modern read without losing the fundamental wedge.
Motorsport pedigree lent real credibility. The name “Trans Am” referenced the SCCA series where Firebird-bodied race cars had long mixed it with Mustangs and Camaros, and Pontiac quietly supported showroom-stock and 1LE road-race efforts. The halo moment came in 1989 with the 20th Anniversary Turbo Trans Am, powered by a Buick-derived turbocharged 3.8-liter V6; it famously paced the Indianapolis 500 and drew headlines for its startling performance.
On the showroom crossfire, the GTA’s rivals ranged from Ford’s 5.0 Mustang LX/GT to Chevrolet’s IROC-Z/Z28—and, at the money end, aspirational imports like Nissan’s 300ZX Turbo and Toyota’s Supra Turbo. The GTA’s pitch was distinct: American GT thrust with Autobahn legs and a genuinely capable chassis, particularly in WS6 form.
Engine and technical specifications
Below are the headline powertrains associated with the GTA and its closely related halo variant. Output figures reflect factory ratings during the 1987–1992 window.
| Engine code & name | Configuration | Displacement | Horsepower (factory) | Induction | Redline | Fuel system | Compression ratio | Bore x Stroke |
|---|---|---|---|---|---|---|---|---|
| L98 5.7L TPI V8 | 90° OHV V8 | 5.7 L (350 cu in) | 225–240 hp (varied by year) / ~330–340 lb-ft | Tuned Port Injection (long-runner, multi-port) | ~5,500 rpm | Multi-port fuel injection with MAF/SD control (by year) | ~9.5:1 | 4.00 in x 3.48 in |
| LB9 5.0L TPI V8 | 90° OHV V8 | 5.0 L (305 cu in) | 205–230 hp (varied by year/trans) / ~285–300 lb-ft | Tuned Port Injection (long-runner, multi-port) | ~5,500 rpm | Multi-port fuel injection | ~9.5:1 | 3.736 in x 3.48 in |
| LC2 3.8L SFI Turbo V6 (1989 TTA) | 90° OHV V6, turbocharged | 3.8 L (231 cu in) | 250 hp / 340 lb-ft (factory rating) | Single turbo, intercooler, SFI | ~5,500 rpm | Sequential fuel injection | ~8.0:1 | 3.80 in x 3.40 in |
Transmissions: the 5.7L L98 was paired to the 700R4 (later 4L60) four-speed automatic; the 5.0L LB9 could be ordered with a Borg-Warner T5 five-speed manual. Final drives commonly ranged from 3.23 to 3.42:1 in performance trims.
Driving experience and handling dynamics
What distinguished a proper GTA wasn’t only straight-line urge, but the way it covered distance. The WS6 chassis package brought higher-rate springs and bars, specific shocks, firmer bushings, and a quick steering box. Up front, a MacPherson-strut layout with a stout lower arm and anti-roll bar delivered accuracy; out back, the live axle was tamed by a torque arm and Panhard rod, with coils at each corner. On 16x8 crosslace alloys and VR-rated 245/50 tires, grip was substantial for the era, and the car felt settled at speed—more GT than brawler.
Throttle response from the long-runner TPI engines is distinctly muscular from low rpm: an off-idle swell of torque that suits real-world driving and relaxed highway work. The trade-off is an upper-range power taper relative to contemporary multi-valve imports, yet on a winding back road the GTA’s composure and traction tell their own story. The T5 manual added involvement to the 5.0 TPI cars, while the wide-ratio 700R4 made the 5.7L L98 a consummate autobahn cruiser thanks to its deep overdrive.
Braking was a step-change over lesser Firebirds. Many GTAs carried the J65 four-wheel disc system with ventilated rotors, confident pedal feel, and better heat capacity than the drum-rear setup of base cars. The rare 1LE road-race package—largely seen on stripped Formulas/Trans Ams—added heavy-duty rotors, specific calipers, and cooling, but was a niche homologation special rather than a GTA staple.
Performance specifications
Representative factory claims and period instrumented tests are summarized below. Actual results vary with year, optioning, and test conditions.
| Model/Powertrain | 0–60 mph | Quarter-mile | Top speed | Curb weight | Layout | Brakes | Suspension | Gearbox |
|---|---|---|---|---|---|---|---|---|
| Trans Am GTA 5.7L L98 (auto) | ~6.0–6.7 s | ~14.5–15.1 s @ 94–98 mph | ~140–145 mph | ~3,400–3,600 lb | Front-engine, RWD | Vented discs (f/r) on J65; some early cars had rear drums | WS6: strut front; live axle w/ torque arm & Panhard rear | 700R4/4L60 4-sp auto, OD |
| Trans Am GTA 5.0L LB9 (manual) | ~6.5–7.0 s | ~15.0–15.5 s | ~135–140 mph | ~3,300–3,500 lb | Front-engine, RWD | Vented discs (f/r) on J65 option/WS6 | WS6 calibration | Borg-Warner T5 5-sp manual |
| 20th Anniversary Turbo Trans Am (1989) | ~4.6–5.1 s | ~13.1–13.9 s | ~158–162 mph | ~3,400–3,500 lb | Front-engine, RWD | Vented discs (f/r) | WS6 with unique calibration | 4-sp auto (200-4R in TTA application) |
Variant breakdown (trims and editions)
The GTA sat within a broader third-gen Firebird lineup that included the base Firebird, Formula, and Trans Am. Below are key variants of direct interest to GTA and its halo derivatives.
| Variant | Years | Production | Drivetrain highlights | Visual/feature differences | Market notes |
|---|---|---|---|---|---|
| Trans Am GTA (coupe) | 1987–1992 | n/a (comprehensive verified total not published here) | L98 5.7 TPI (auto); LB9 5.0 TPI (manual/auto) | Body-color aero kit, GTA badging, 16x8 crosslace wheels, WS6, upscale trim | Sold primarily in the U.S.; Canadian availability |
| Trans Am GTA (convertible) | 1988–1992 | n/a (ASC-built numbers vary by year) | Same engine mix; automatic prevalent with L98 | Power soft top conversion by ASC under factory authorization | U.S.-led; limited volumes relative to coupes |
| Trans Am GTA Notchback | 1988–1989 | n/a (very low-volume; documented totals vary) | As GTA; offered with L98/LB9 | Dealer-installed/authorized hatch conversion with near-vertical rear glass and flat deck | Niche; sought by collectors due to rarity |
| 20th Anniversary Turbo Trans Am (TTA) | 1989 | 1,555 total (widely documented) | 3.8L SFI turbo V6, 4-sp auto (200-4R), performance calibration | White with gold accents, Indy 500 graphics on pace cars, specific aero/wheel details | Primarily U.S.; includes T-top and hardtop, plus a small run of convertibles |
| Firebird Formula (context) | 1987–1992 | n/a (varied by year) | Shared performance engines (5.0/5.7 TPI) in lighter body | De-badged look, minimal aero addenda, sleeper appeal | Popular with 1LE road-race builds |
- Turbo Trans Am breakdown is widely cited as 1,324 T-tops, 187 hardtops, and 24 convertibles within the 1,555 total.
Ownership notes: maintenance, parts, restoration
- Engine and fueling: TPI small-blocks are robust with regular fluid changes. Common age-related items include MAF sensors (where fitted), plenum/runner gaskets, EGR valves, and vacuum lines. Ignition is conventional distributor/coil—cap, rotor, and wires are wear items.
- Transmissions: The 700R4/4L60 responds well to correct TV cable setup and fluid service; abuse and heat are the enemy. The Borg-Warner T5 is adequate for 5.0 torque if not shock-loaded; use correct fluid and shifter bushings.
- Chassis: Inspect torque-arm bushings, Panhard rod ends, front control-arm bushings, and steering box play. WS6 cars reward fresh dampers aligned to factory specs.
- Brakes: J65 four-wheel discs improve consistency; the rear parking-brake mechanism can stick if neglected. Quality pads and fresh hoses transform pedal feel.
- Body/interior: Third-gen hatchbacks can develop rattles; check hatch struts and latch adjustment. Door hinge pins/sag, window motors, headliner adhesive, and interior plastics are known aging points.
- Parts availability: Mechanical parts are plentiful and shared with broader GM catalogs. GTA-specific trim (badges, crosslace wheels, cladding) is available, though mint OE pieces and Notchback components are more challenging.
- Restoration difficulty: Straightforward mechanically; the challenge is finding correct, unmolested interior and exterior details. Documentation (build sheet, RPO label, original window sticker) adds significant value.
- Service cadence: Oil every 3,000–5,000 miles depending on use; transmission and differential fluids at sensible intervals; cooling system and brake fluid on schedule; periodic injector cleaning helps maintain TPI drivability.
Cultural relevance and collector lens
The GTA distilled Pontiac’s performance ethos into a grand-touring package—long legs, serious grip, and understated swagger. Pop culture cemented the third-gen Firebird’s image (the earlier KITT connection didn’t hurt), but the period-defining moment for this generation was the 1989 Turbo Trans Am pacing the Indianapolis 500 with showroom power. Period tests noted the TTA’s acceleration and high-speed stability as exceptional for its time.
Collector desirability centers on originality and specification. Well-kept L98 GTAs with WS6 and four-wheel discs are perennial favorites; 5.0 TPI/T5 cars appeal to purists for the manual gearbox. The 20th Anniversary Turbo Trans Am sits at the top of the pyramid—limited build, authentic competition association, and performance that stands up. Documented auction results have recorded premiums for low-mile, unmodified examples, with the TTA regularly outpacing standard GTA values.
FAQs
How powerful were GTA engines?
The 5.7L L98 TPI V8 was factory-rated between 225 and 240 hp (depending on year/calibration), with roughly 330–340 lb-ft of torque. The 5.0L LB9 TPI ranged roughly 205–230 hp. The 1989 Turbo Trans Am’s 3.8 SFI turbo V6 was rated at 250 hp and 340 lb-ft.
Could you get a manual with the 5.7L (350) GTA?
No. The 5.7L L98 was automatic-only in F-body applications. The manual gearbox (Borg-Warner T5) paired with the 5.0L LB9.
What’s special about the WS6 package on a GTA?
WS6 brought uprated springs/bars, specific shocks, performance alignment, quick steering, and (on many cars) four-wheel disc brakes—transforming the Firebird into a genuine grand tourer.
How quick is the 1989 Turbo Trans Am?
Period instrumented tests recorded approximately 0–60 mph in the high-4 to low-5 second range and quarter-miles in the low- to mid-13s. Top speed was measured around the 160 mph mark.
Known trouble spots?
Age-related TPI vacuum and sensor issues, door hinge and window-motor wear, hatch rattles, torque-arm and suspension bushings, and (where fitted) sticking mechanisms in the rear disc parking brake. Proper TV cable adjustment is vital on 700R4 automatics.
Value trends and auction prices?
Documented sales consistently show that unmodified, low-mile cars with complete paperwork command strong money, with the 20th Anniversary Turbo Trans Am typically achieving the highest prices relative to standard GTAs.
What’s the story on the GTA Notchback?
It was a low-volume, dealer-installed/authorized hatch conversion offered in 1988–1989 with a unique rear profile. Surviving cars are scarce and collectible; verified production totals are limited and vary by source.
