roads both during cornering and on acceleration at low speeds.
Axle hop on takeoff was supposedly eliminated by the twin trailing arms fitted to all “sporting” Firebirds. The test Sprint, however, exhibited poor axle control. Takeoff was accompanied by a period of violent hop, unless a very gentle “roll-out” was employed. Brake hop also was noticeable, but not as frequently encountered.
It was during ride-quality evaluation of the Firebird Sprint that the term vintage first came to mind. The Sprint delivered the same sort of rock-solid, back-slapping ride familiar to early post WW 11 sports cars. To those who associate ride firmness with superior handling, the Firebird meets their requirements. Most obvious among ride deficiencies in both Firebirds was a lack of free spring travel. The springs were forced to absorb all road irregularities in about 3 in. of travel, and it the bump was too severe to allow the stiff springs to accommodate it, the jounce bumpers entered the picture with a resounding bang. Other manufacturers, principally in Europe, have caused live axle layouts to produce a very comfortable ride while providing superb handling. Pontiac has not.
The Firebird Sprint, then, was an exciting car to drive hard on smooth roads. It was not particularly fast or
economical, delivering less than 14 mpg during testing. It was not particularly comfortable, though turnpike or smooth highway ride was acceptable. An enjoyable car? Yes! An attractive car? Yes! A reliable car? Undoubtedly! A European-style GT car? No!
The Firebird 400 came closer to fulfilling its advertised goals than did the Sprint. The 400 is the most powerful, fastest of the Firebird family, and one of the fastest of Ponycars. Preceding comments on ride and handling apply to the 400 as much as they do to the test Sprint. The Firebird 400 exhibited slightly more understeer at low speeds, but could easily be placed into power oversteer attitude with a nudge on the accelerator pedal. Ride quality of the 400 was slightly superior to the Sprint, but still quite vintage.
PERFORMANCE, SPELLED acceleration, was the 400’s forte. The 400-cu. in./325-bhp engine is a beautifully flexible, quiet, tremendously responsive powerplant. Around town, the only difficult task was avoiding flagrant speed limit violation. The engine seemed quite happy motoring along just above idle, but a few periods of this sort of operation did foul spark plugs. Once on the open road, a few bursts of speed cleared the plugs, and the 400 flexed its muscles.
was impressive in any gear, at almost any speed. The Firebird 400 would pull strongly to just over 5000 rpm, where hydraulic lifter pump-up was encountered. In high gear, the 400 would run out to valve float in an amazingly short period of time.
A quarter-mile elapsed time of 14.7 sec. is exceptional for an automobile in full street trim, with two passengers and test gear aboard. Only the 427 Corvette, and Hemi-powered Plymouths and Dodges are capable of times quicker than this, and that places the Firebird 400 in the very uppermost echelon of domestic Supercars.
The 400 is likely to be the enthusiast’s choice among Firebird’s lineup. It was definitely CL’s choice of the two test cars. The 400 simply made more sense. Neither car was a sports car, although both compare favorably in handling ability with others in the Ponycar brigade. Neither car was particularly economical, though the 400’s near 12 mpg during hard driving was considered quite acceptable. The 400 delivered outstanding performance, unhampered by power-robbing emission reduction apparatus. To the average American purchaser, particularly one inclined toward Firebird-type vehicles, acceleration makes up for numerous faults. The Firebird 400 has acceleration, in spades.