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worked on the now perfected PG 1493.
And, oh yes: 1493 was also being
used in another rush project, the de-
velopment of an IRS for the soon-to-
be-introduced
production
1965
Mustang, which took the name from
the original two-seat concept car. Its
first tests by Shelby were done at
Riverside in February of 1964, in-
stalled in an early notchback.
As verification that Ford had in-
deed intended its new Mustang to be
offered with an IRS, when Iacocca in-
troduced the Mustang to the media at
the New York World’s Fair in April of
1964, he told the press, “
An independ-
ent rear suspension is in the works
.”
Of course, the Mustang IRS never
made it into production, but the ability
to develop a suspension system before
it ever hit the track – a capability
birthed by Arning’s Advanced Suspen-
sion and the Mustang I Concept car –
became central to Ford’s racing efforts.
When A.J. Foyt won Indy in 1967 and
then two weeks later won LeMans
with Gurney in a Ford GT MK IV, a re-
porter asked him how he could win
two big races in such different cars.
Foyt is quoted as saying, “
They
weren’t that different; they were de-
signed by the same guys.
” What he
could have said was they were
“de-
signed by the same computer
.”
The Original Venice Crew built
their 2015 version of a 1965 Shelby
GT350R Mustang in Brock’s own shop
in Henderson, Nevada with an inde-
pendent rear suspension. The car was
previewed it at Willow Springs on Feb-
ruary 14, exactly fifty years from the
date of the GT350’s first race victory
at Green Valley Raceway in Texas.
Hemmings.com
interviewed Brock
and asked him specifically about the
Mustang IRS: “
Plans for Carroll
Shelby’s GT350R Mustang originally
called for an independent rear suspen-
sion, later abandoned for cost reasons.
Do you think this would have made a
significant difference in the car’s per-
formance, and do you think that costs
could have been contained to a reason-
able level?
”
With his reply to the reporter’s
question, Brock shed new light on the
reason that first Mustang never saw
an IRS: “
The independent rear sus-
pension that Ford’s engineer Klaus
Arning designed
for
the Shelby
GT350R Mustang wasn’t that expen-
sive to produce, but it was labor inten-
sive to retrofit on a car that had been
designed to use a live axle. Time was
another factor in the decision – we did-
n’t have enough of it. Then, the
GT350R proved competitive with its
original setup, and in racing when
something ain’t broke, you don’t fix it.
”
As any true Ford fan knows, the
all-new-for-2015 regular production
Ford Mustang finally came to market
with a factory designed, developed and
installed independent rear suspen-
sion. Klaus’ son, Ralph Arning, himself
a Ford engineer who has spent
decades supporting production of the
Mustang, was working at the Flat
Rock Assembly Plant when that very
first IRS-equipped production Mus-
tang came down the line.
The SHELBY AMERICAN
Duane Carling and the re-imagined GT350
R with independent rear suspension. Car-
ling’s article was originally published by
John Clor on March 24, 2016 on Ford Rac-
ing’s website
fordperformance.com
Original illustration of Mustang IRS.
Summer 2016 66