IMSA GTP’S GREATEST CARS
Mention the acronym “GTP” to
anyone who witnessed the wild
creations that ran amok in the
International Motor Sport
Association’s premier class from
1981 to ’ 93 and you’re all but
guaranteed to hear some amazing
tales about North America’s
defining sports car class.
Grand Touring Prototype cars
were the perfect fit for a party-filled decade where excess was a
way of life. IMSA’s GTP rulebook
was more of a suggestion than an
iron-clad agreement, and from that
deep well of opportunity, demonic
power, astronomical speed,
incredible looks and heavenly
sounds were conjured.
IMSA’s thunderous show was the
envy of the ACO and FIA, struggling
to make Group C a global
phenomenon. During its richest
period, GTP produced some truly
great cars, along with concepts
ranging from ingenious to idiotic,
and it remains a benchmark for
spectacle and variety even today.
Here then are some of the giants
of the GTP era – cars we are proud
to say called America home.
Without Porsche’s turnkey prototype, GTP would be remembered as a
failed experiment. Introduced at the
1984 Daytona 24 Hours, it was the first
purpose-built factory car for the GTP
class – an IMSA-compatible version of
Porsche’s 956, to all intents and purposes
– and went on to fan the flames that
sparked IMSA’s rising popularity.
The 962’s brilliance was in its utilitarian
design. It was never the most powerful or
best handling car, but it also didn’t possess
any show-stopping weaknesses. It was the
best “sum of the parts” GTP car for four
glorious seasons, could still scramble to a
race win as late as 1993, and continues to
stand as the ultimate Pro-Am prototype.
In the legendary hands of a Derek Bell,
Al Holbert, Jochen Mass, Hans Stuck or
Bob Wollek, the 962’s pace was an
absolute killer. And in another Porsche
hallmark, its drivers could hammer away
near the limit while other marques were
often constrained by reliability concerns.
Piloted by privateers like Bob Akin, Jim
Busby, Bruce Leven, and countless others
who cast the mold for today’s Pro-Am
drivers, the 962’s flat-six turbo engine,
methodical, forgiving gearbox, and ample
downforce delivered a driving experience
that didn’t twitch or bite, but instead
flattered its users with easy to find speed.
The 962 served all purposes, but if
PORSCHE 962 – 1984-’ 93
there’s one aspect of its vast legacy that
IMSA’S SWISS ARMY KNIFE… 1
has been somewhat overlooked, it’s the
car’s alarming overall pace. Holbert
Racing found the 962’s sweet spot
halfway through 1984 and went on to
claim five wins from the final nine races.
With Holbert’s mighty No. 14 leading the
development charge for ’ 85 – and Porsche’s
customer base exploding during the
preceding offseason – the 962 authored the
most dominant GTP season on record, when
five teams contributed to an unprecedented
figure of 16 wins from 17 races.
Holbert Racing repeated in 1986, as
962 teams took 12 of 17 races and
stuffed the sharp end of the
championship with eight drivers in the
top nine in points. Holbert Racing’s title
three-peat was completed in ’ 87, when
the 962 fleet snared 13 wins from 116.
During the 962’s three-year GTP title
run in 1985-’ 87, seemingly impossible
win rates of 94, 70 and 81 percent were
recorded. Those figures stand as a
testament to the car’s base design, and
the ability of teams to apply an endless
Iterations of the 962 won five times at
the Daytona 24 Hours. Busby Racing
took win No. 4 in 1989 (ABOVE), with
John Andretti, Derek Bell and Bob Wollek.
WORDS Marshall Pruett
MAIN IMAGE Jeff Zwart