Pontiac Firebird Formula

Firebird Formula at a glance

Formula 400: a Trans Am in plain clothes

Pontiac showed the second-generation Firebird at the Chicago Auto Show on 26 February 1970, with four models: Firebird, Esprit, Formula 400 and Trans Am. The Formula took its name from open-wheel racing and replaced the 1967-1969 Firebird 400. It had no stripes, spoilers or wing flares, but it could take most Trans Am options; the exceptions were the wheel-arch flares, the shaker scoop and the wing air extractors. Inside it used a deluxe steering wheel and a woodgrain gauge panel instead of the Trans Am's engine-turned metal.

The standard engine was the L78 400 with a Rochester four-barrel, 10.25:1 compression, 246 kW (330 hp) at 4,800 rpm and 583 Nm (430 lb-ft) at 3,000 rpm. For US$168.51 in 1970, buyers could order the L74 Ram Air version with 10.75:1 compression. Old Cars Weekly quotes 250 kW (335 hp) at 5,000 rpm for it; Wikipedia lists 335 hp with the automatic and 257 kW (345 hp) with a manual gearbox. The Ram Air IV, offered in the Trans Am, did not reach a single Formula.

The Formula's long twin scoops opened just above the grille. With the Ram Air engine, two rubber-sealed ducts under the bonnet fed the carburettor with outside air, and "RAM AIR" decals appeared on the scoops. Firmer springs and dampers, anti-roll bars front and rear and power front disc brakes were standard. Car and Driver measured 6.4 s to 60 mph and 14.7 s at 98.9 mph over the quarter mile, a little slower than the Trans Am it tested, which cost US$4,663.63 in 1970 at the same time.

Formula 455 and the Super Duty years, 1971-1974

For 1971 the Formula became three models, each with its displacement on the lower front wings: Formula 350, Formula 400 and Formula 455. The 455 came as the L75 with D-port heads or as the LS5 455 HO, the Trans Am engine with round-port heads, rated at 250 kW (335 hp, SAE gross). Of the 7,802 Formulas built in 1971, 321 had the 455 HO (166 manual, 155 automatic) and 350 the L75. Tran-Zam counts 159 of the manual HO cars with the close-ratio M22 four-speed.

The change from gross to net ratings in 1972 makes the 455 HO look weaker on paper, at 224 kW (300 hp). For 1973 the twin-snorkel bonnet gave way to the Trans Am's shaker scoop without the bird decal, and the shaker was no longer functional. Tran-Zam lists that year's Formula 400 at 172 kW (230 hp), while the L75 455 had 186 kW (250 hp) at 4,000 rpm and 502 Nm (370 lb-ft) at 2,800 rpm. Production split into 4,771 Formula 350s, 4,622 Formula 400s, 730 Formula 455s and 43 cars with the Super Duty 455. For 1974 the Formula received the sloped nose and rubber bumper strips that met the new 5 mph bumper rules; 702 cars had the L75 455 and 58 the Super Duty.

Production 1975-1981 and the first exit

After 1974 the big engines left the Formula first. When the 455 HO returned in mid-1975 with 149 kW (200 hp), it was not offered in the Formula, and from 1976 the 455 was a Trans Am engine only. Sales grew anyway, helped from 1976 by the W50 Formula appearance package, and peaked with the second generation.

In 1980 neither the Formula nor the Trans Am could be ordered with a manual gearbox. The third-generation Firebird of 1982 started without a Formula, and the name stayed off the price list until 1987.

Formula after 1987: TPI, LT1 and LS1

The 1987 Formula returned as a lighter, cheaper car below the GTA, with the Turbo bulge bonnet, 16-inch wheels and WS6 suspension as standard. Engines were the carburetted LG4 305, the LB9 305 with tuned-port injection and the L98 350 TPI. With the N10 dual-catalyst exhaust of 1989 the LB9 reached 168 kW (225 hp) and the L98 175 kW (235 hp), and Car and Driver (March 1990) found the Formula about 136 kg (300 lb) lighter than a GTA, with 0-60 mph under 7 seconds.

The fourth-generation Formula of 1993 used the 5.7 L LT1 with 205 kW (275 hp) and 441 Nm (325 lb-ft), and a T56 six-speed manual or 4L60 automatic. Dual catalytic converters lifted it to 213 kW (285 hp) in 1996, and the WS6 Ram Air package of 1996-1997 brought back working twin-inlet bonnet scoops with 227 kW (305 hp) and 454 Nm (335 lb-ft). The aluminium LS1 arrived in 1998 at 227 kW (305 hp), or 239 kW (320 hp) and 468 Nm (345 lb-ft) with the WS6 option, which cost US$3,150 in 1998. LSX Magazine counts 7,198 Formula coupés from 1998 to 2002, falling from 2,123 to 901 a year. GM announced on 25 September 2001 that 2002 would be the last year of the Firebird and the Camaro.

Formula or Trans Am: what to check today

The Formula's engine badge was its identity in 1971-1974, so a Formula 455 should carry the matching wing callouts and the engine to go with them. Small batches matter most:

• 689 Ram Air III cars among the 7,708 Formulas of 1970.
• 321 Formula 455 HOs in 1971, of which 159 had the M22 four-speed (Tran-Zam).
• 101 Super Duty Formulas in 1973-1974: the 43 of 1973 are split 33 manual and 10 automatic by Tran-Zam, while Street Muscle says only 10 were manual.
• About 50 N10 "sleeper" Formulas a year with the TPI engines and a five-speed in 1989, according to Car and Driver.

The Formula shared its body with the Camaro of the same years, from the second-generation Camaro and its Z28 to the fourth generation. Its louder sister is described in our Firebird Trans Am hub, the whole line in the Pontiac Firebird guide, and its place among the period's cars in the American muscle car guide.