A last-gasp effort to extend the DFX’s
lifespan resulted in 1989’s short-stroke
Cosworth DFS. The project started in
earnest back in ’ 86 as a private
response to the rising Ilmor-Chevy tide.
“Carl Haas, Paul Newman and the
team I drove for, TrueSports, initially got
together to fund what led to the DFS,”
says triple CART champ Bobby Rahal.
With Mario Andretti in the
Newman/Haas Racing entry and
Rahal in his TrueSports car, the pair
put the extra revs to good use
through the end of the year. But Mario
and NHR were switching to Ilmor in ’ 87.
As the Ilmor-Chevy asserted its will
and pushed the DFX to the margins,
the Bowtie held tight control over its
engine supply. Taking its cue from the
DFXs, in 1989 Cosworth offered its
own take on the theme, the DFS, to
meet the needs of CART’s have-nots.
Unable to get a Chevy lease, Rahal
– now at Kraco – along with other
out-of-favor programs like Dale Coyne
Racing and Dick Simon Racing, was left
to rely on the DFS. His ’ 89 win at the
Meadowlands was its sole triumph.
“The DFX held its own for many
years until Ilmor came along,” Rahal
says. “Then when things like engine
leases came up, that was the end of
that. We had our win with the DFS, but
its time had passed. It wasn’t until the
Cosworth XB came out in ’ 92 that they
got themselves back in the game.”
(TOP) DFS was too little, too late when it
appeared. XB replaced it in 1992, returning
Cosworth to Indy’s Victory Lane in ’ 95,
courtesy of Jacques Villeneuve (ABOVE).
Ilmor Engineering’s 2.65-liter Chevrolet
V8 turbo, the 265-A, was on track. For ’ 87,
Newman/Haas Racing and Patrick Racing
signed on alongside Team Penske, and as
NHR driver Mario Andretti noted, it was
obvious that Illien and Morgan had taken
smooth power delivery to a new level.
“When I did a comparison, the DFX
would come on really harsh, but the Ilmor
didn’t,” Andretti says of his first Chevy test.
“At first, you’re thinking, ‘S**t, there’s no
power,’ and then you look at the lap times
and you’re quicker. The power range was
much wider on the Chevy.”
A familiar name had been tabbed by
Penske to debut the Ilmor-Chevy at Indy in
1986. Al Unser qualified fifth, but retired
as the DFX prevailed again, this time with
Bobby Rahal and Truesports.
By ’ 87, Ilmor had the Chevy V8 honed
and ready to kick the last bit of dirt on the
DFX’s grave. But an old friend of the VPJ
Turbo Engine managed to delay the
inevitable. That man Unser, in a last-minute,
DFX-powered extra Penske entry – a year-old
March liberated from a hotel lobby – stole
the show from an uncatchable Andretti,
whose Chevy failed 23 laps from the finish.
First man to test the VPJ Turbo Engine,
at the wheel for its maiden win in Pocono,
and the first to win Indy with the DFX,
Unser rightfully earned its final victory
at the Speedway, joining the Indy 500’s
four-time winners club in the process.
“It was a fun time going against Chevy
and outrunning them all,” a devilish Unser
(ABOVE) The last
hurrah... With Ilmor-built Chevy engines
in the ascendancy, Al
1987 Indy 500 win
was the 10th and
final victory for a
The Ilmor-Chevy (ABOVE, in 1988 Chevy
Indy V- 8 guise) did everything a bit better
than a DFX, sealing the Cosworth’s fate.
ILMOR-CHEVY: DFX SLAYER
“It was a fun time going against
Chevy and outrunning them all.
It just meant a lot”
admits. “It just meant a lot.”
His Ilmor-Chevy beaten by his own team,
Penske was determined to kill the DFX
in 1988, and 14 wins from 15 races,
including a third Indy win for Mears, did the
trick. But a piece of Indy car racing also
died when the DFX met its inevitable end
and factory programs and pricey engine
leases took hold in CART and beyond.
Even now, as the sport continues to look
for ways to wind back the clock to Indy
car racing’s simpler days, the Cosworth
DFX, last of its off-the-shelf, high-performance solutions, is greatly missed.