The 1964 Pontiac GTO didn’t just appear out of thin air; John Z. DeLorean had been working his way towards a genuine American GT for several years with the 1961-1963 compact Tempest. The ’61 arrived with one half of the future GTO’s 389 V8, including a four-barrel hi-po version. And there was the rear transaxle with independent rear suspension; DeLorean was a big IRS fan, although the Corvair’s borrowed swing axles were not really optimal.
But that was just the first act; for 1963, Pontiac ditched the expensive and rarely installed optional Buick 215 aluminum V8 and dropped in a reduced-bore version of the 389 V8. In an (initial) concession to appearances of modesty, it came with only a two-barrel carb, rated at 260 hp. But as the year progressed — with the GTO already waiting in the wings — a 280 hp four barrel HO version became available too.
This CL review is of a 260 hp version backed by the two-speed automatic. Not exactly quite a full-grown tiger yet, but it was already showing its stripes.
Actually the so-called 326 displaced 336.66 cubic inches. Why Pontiac advertised that it had 326 cubic inches is a mystery; GM’s edict that intermediates shall have no more than 330 cubic inches didn’t come out until 1964, so for ’64 the bore was reduced again to make it a genuine 326. But of course that rule was then totally flouted by the 389 GTO. Does any of this make sense?
CL suggests that the Tempest LeMans was something of a 7/8 size budget Grand Prix; a logical call. The ’63’s longer and wider external sheet metal did elevate it visually into a genuine mid-sized car even if its internal body structure was still all very much the same; also largely shared with the Corvair. CL suggests that after driving it for a while, no one will ask why Pontiac didn’t just drop in the 389 as the 326 has more than enough beans to spin the rear wheels on command.
The two-speed torque converter automatic had a lot of Powerglide DNA in its case, but there were some changes from the ’61’-’62 “Tempest-Drive” version. The unit shifted more smoothly and was deemed an improvement over the previous version, having ditched its torque-splitting top gear function.
Total torque multiplication with the 3.09 rear axle was too much for the skinny 6.50-15 tires, resulting in excessive wheel spin. Hitting the throttle even lightly three-quarters of a way through a turn caused the rear end to swing out of control. A higher (lower numerical) axle ratio was recommended. Contrary to popular belief thanks to a famous movie scene, a limited slip differential was not available. The presumed reason the ’62 Corvair’s Positraction unit wasn’t used is because a larger and stronger differential had to be used with the V8.
“Of course, driving a car with so much power is great fun“. 0-60 came in 9.5 seconds, not exactly a stellar number, but reasonably quick for the times. A version with the three-speed manual was tested by Popular Science as part of a comparison test, and it was faster with a brisk 8.1 second 0-60 time. The specs showed that car having a 3.90:1 rear axle, although the brochure does not show that as optional.
Of course the 280 hp four-barrel 326 HO version that came later in the year was faster yet, with a 0-60 time of just under 7 seconds and the 1/4 mile in 17 seconds (Car Life test). That 0-60 time is very much in ’64 GTO territory, even if the 1/4 mile ET isn’t quite.
At a cruising speed of 80 the Tempest felt like it was “loafing“. It conveyed the sense of a larger car, although its ride and road/engine noise didn’t quite, undoubtedly due in part to its unibody construction.
The power steering was too slow, with some 5 turns lock-to-lock. The 9” brake drums should have been upgraded; they were marginal.
The four speed manual (borrowed from the Corvair) was not strong enough to use with the V8, so a three-speed was the only manual gearbox available, but with such a torque-rich engine in a relatively light car, the lack of the extra gear was probably not really an issue except for racing. As it was, the three-speed was a bit marginal and there were reports of damage from enthusiastic shifting.
The instrument panel was new for ’63 and attractive in appearance with four large round openings, but the details of its layout were not quite optimum. It’s a testament to the Corvair’s relatively roomy interior that essentially the same cabin was deemed quite suitable in that regard in the Tempest.
Very little or nothing was said about the revised rear suspension for ’63; it still used swing axles but now used L-shaped control arms instead of semi-trailing arms. This reduced toe-in changes as the camber changed. The Tempest had acquired a rep for its tricky rear end manners (snap oversteer when exceeding its limits); the ’63 version was a minor improvement but did not go far enough. A camber-compensating spring like the ’64 Corvair had would have been a good start.
CL made no real mention of the Tempest’s handling; maybe because its vices were already known and they didn’t want to rub it in further? Or perhaps they just didn’t drive it in the kind of conditions where the rear end was likely to act up.
The final verdict was positive, although there was some discomfort with the Tempest’s seemingly inevitable external growth. Well, that too was just the warm up act for the ’64 Tempest and all the new GM A-Bodies. They were headed for growth, but most of all, lots of performance increases, starting with the GTO. The ’64-up GM A-Bodies would be the beginning of the biggest change in GM’s long history, as these cars and their successors would eventually muscle out the large cars for sales superiority. So yes, the ’63 Tempest was more than just a warmup act for the GTO; it was a the beginning of a revolution.
Related CC reading:
Ate Up With Motor has a very in depth look at the ’61-;63 Tempest:
Magnificent Kludge: The ‘Rope-Drive’ 1961–1963 Pontiac Tempest