Page 17 - On the Prowl: The Definitive History of the Walkinshaw Jaguar Sports Car Team

ON THE PROWL
1988: TWR Takes on America
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Bush had been hired from the Benetton F1 team, where he had
become weary of the organizational politics. “I got a call from one of the
guys in the TWR shop in the early autumn of 1987. He said, ‘Hey, Roger’s
looking for a guy to be chief mechanic on the Jag IMSA team. Are you
interested?’
“Roger said to me in my interview, ‘I need you to go there and
establish the flavor of the team.’ Those were his exact words. And he
says, ‘and you know what I mean by that. I don’t want some American
circus act.’ But what Roger didn’t realize is, racing in America is the way
it is, because that’s the way it has to be. You don’t go to live in Japan and
try to recreate Birmingham.
“After I was hired, we built the IMSA car in Kidlington and then we
brought it over at the end of October ‘87. My intention was to stay here
[in the USA] for a couple of years, make a bunch of money, go back to it
and pay off my mortgage and retire at forty-five. Thirty-odd years later,
I’m still here!”
Soon the other two IMSA cars joined #188 in the US, with #288
having received a shakedown from John Watson at Donington Park prior
to leaving. Watson was impressed, finding the car easier to drive than
the XJR-8. The smaller engine wasn’t yet ready so he had more power
at hand, and TWR Inc. would have to test with the 7.0-liter unit for the
remainder of the year. Allan Scott’s team was just buried with work,
juggling the development of the Holden V8 for Walkinshaw’s burgeoning
Australian business, along with supporting the JaguarSport joint
venture. Reducing engine capacity wasn’t as simple as just increasing
the length of the piston connecting rods or changing the crankshaft
geometry. When using high-octane race fuel, a higher compression ratio
could be used too, but that changed how the combustion behaved, and
demanded subtle redesigns of valve ports and the piston crown. It was
not the work of a moment.
By November, testing could begin and #188 and #388 were used to
practice race craft, such as pit stops and driver changes. Said Dowe of
the experience: “We had a test at a place in the middle of nowhere called
Big Spring, down in Texas. The thinking was that if we could survive a
race track that had zero facilities, at least it would highlight what we were
missing!”
The first proper test for the cars was at Daytona, this time with #188
and #288. Ian Reed’s extensive notes from the test indicated where
they found problems, and the help they needed from the UK. Over the
course of the two days, they made good progress on figuring out the tire
compounds, spring rates, suspension geometry and aerodynamic setup.
The biggest problem was an issue of direction: most European race
tracks run clockwise. Naturally, if an engine designer needs to decide
which side of the engine to put the oil scavengers, they will favor the
left, as centrifugal forces push the oil that way in most corners. In the
US, most tracks (including Daytona) are counter-clockwise, and with
the added complication of the 31-degree banking it became difficult for
the engine to maintain sufficient lubrication. It also meant a big pool of
oil sitting in the bottom of the engine and dragging on the bottom end,
robbing power. As a result, an additional oil scavenger pump was added
for the first race.
The switch to seventeen-inch wheels had eliminated driveshaft
failures but the unique Daytona circuit was now putting extra strain on
wheel bearings. Reed asked Kidlington for something better. He also
asked for help dealing with the heat; it was becoming clear that the XJR-
9 was not well-suited for high-temperature races. After all, the visits to
Spain and Japan had been during Spring, and Le Mans in 1986 and 1987
was not hot. The Jaguars had not seen the kind of heat that would be
found at some of the IMSA races like California’s Sears Point in August
and the Texan street track of San Antonio in September.
vHalf an XJR-9, perhaps an
XJR-4.5? As the winter of 1987
progressed into 1988, each of the
three IMSA cars were built up and
entered the testing program. This
is chassis #288, which would go
on to contest 27 races and claim
some very significant victories.
(Michael Abraham)
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