Tuesday, October 15, 2024

1977 Pontiac Firebird Trans Am


During the Malaise Era, increasing emphasis on fuel economy and reduced emissions both gaveth and tooketh away. As an example, it was the decision by corporate management at General Motors to cap compression ratios at 8.5:1 so all cars could run on regular unleaded that caused Pontiac to slip a 455 V-8 under the hood of the Firebird.

This allowed for some of the last really blisteringly quick cars of the Muscle Car era, culminating in the '73 Trans Am with the optional Super Duty 455.

However as time went on, mileage expectations increased while allowable emissions decreased. The various special versions of the 455 went away, and by the 1976 model year all that was left was the Plain Jane L75 version of the 455, reduced to a 7.6:1 compression ratio and a 200 SAE net horsepower output, a shadow of its former glory.

1977 saw the disappearance of the 455 altogether. As a consolation prize, Pontiac's engineers worked up a version of the 400 to fill the gap. The top performance option in the '77 Trans Am, the new W72 400 featured a Rochester Quadrajet carb, new heads, and an 8.0:1 compression ratio that let it match the 200 horsepower output of the previous year's bigger L75.

The rest of the Firebird's engine lineup got a shuffle, too. Gone was the straight-six base motor, replaced by a Buick-sourced 3.8L V-6. The base V-8 was the 145hp Pontiac 301, and optional V-8s included the Pontiac L76 350, rated at 170 hp, and the 180hp L78 400.

Firebirds and Trans Ams sold in California got different engines, with the optional V-8 in base cars, Esprits, and Formulas being the Oldsmobile 350 and the Trans Am's V-8 substituted with a 403 cube Olds motor. Towards the end of the model year, the 301 Pontiac V-8 got subbed with a 305 Chevy small block.

Buyers got mad about finding Olds, Chevy, and Buick engines under the hood of their racy Pontiacs, and there were lawsuits and refunds. This is ironic because starting with the very first 2nd Gen Firebirds the base straight-six was sourced from Chevrolet, as Pontiac's own OHC six was too tall to fit under the hood.

Externally, the '77 Firebirds got a new snout with a pointy beak and quad rectangular headlamps. 1977 cars can be discerned from 1978 ones by the grille mesh, which is a honeycomb pattern on the former and a rectangular mesh on the latter.

When Car and Driver put a 1977 Trans Am with a W72, backed with a 4-speed manual and a fairly tall 3.23:1 rear end, through its testing procedures, they noted a zero-to-sixty time of 9.3 seconds and a quarter mile time of 16.9 at 82 mph. The car topped out at 110 miles per hour and, still sporting front discs and rear drums, it took 213 feet to bring the 3,830-pound T/A to a halt from 70 mph. Price as tested was $8,161, or the equivalent of $42,400 current-year dollars.

The honeycomb grille of the Cameo White car in the photo makes it a '77 model, and the "T/A-6.6" decal on the shaker scoop tells us it has the W72, since the lowlier L78 motor would have a scoop that read "6.6 LITRE". It was photographed with a Canon EOS 5D Mark II and an EF 24-105mm f/4L zoom lens in December of 2018. 

2 comments:

  1. It's actually the 2nd-gen Firebird that has hood clearance issues with the OHC-6, which was a contributing factor to its demise after '69.

    Hopefully that '77 really does have a W72 under the hood and not just a restickered shaker. The rear wheelwells have also been widened and flared, not unheard of back in the day.

    ReplyDelete

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