Bruns' Eagle Mods
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Engineering, located in San Clemente, Calif. south of Los Angeles,
is revered by U.S. road racers as a source of great racecars.
Twenty years ago most racers competing on American tracks had
to buy racecars designed and built in England and sold in this
country by an importer/distributor like Carl Haas. The David
Bruns-designed Swift DB-1 (DB for David Bruns' initials) Formula
Ford began racing late in 1983 and quickly eclipsed all the other
FF cars available. The British designers had always just shipped
their cars over here whenever they made one that fit American
rules. Bruns (shown in photo) actually did some engineering analysis
and designed a car just for American tracks and tires and drivers.
The distinctive characteristics of the DB-1 were a wide track,
long wheelbase, and low frontal area. The result was the DB-1
would corner faster, reach higher top speeds, and was easier
to drive than the other cars. All that for less than $16,000
without engine, the same as a new Lola.
The next Bruns design was a sleek Sports 2000 car, the DB-2.
The DB-3 was a Formula Ford 2000, the DB-4 a Formula Atlantic
racer, the DB-5 an updated Sports 2000, and the DB-6 a redesigned
FF2000. In the early 90s Swift began to talk about making a "big
car" which at the time meant a GTP sports car. Indy cars
were languishing but the IMSA GTP races were exciting and had
the support of auto makers like Porsche, BMW, Toyota, Ford, Chevrolet,
Hiro Matsushita won the Formula Atlantic championship in 1989
driving a Swift DB-4. He bought Swift Engineering in 1991 and
provided the money to build a state-of-the-art wind tunnel, an
indispensable tool for a "big car" designer. Typically,
Bruns did some research and then designed his own wind tunnel
rather than buying one from a known supplier. It was a costly
project that strained the fledgling company.
In November of 1994 I visited Swift during the final stages
of certification of the new wind tunnel. Bruns told me, "It's
like deciding to build a house and then spending two years making
a hammer." By that time the IMSA GTP series had declined
and Indy car racing was prospering in spite of a nasty tiff between
Tony George, president of the Indianapolis Motor Speedway, and
Swift was run by a triumvirate of racers: Alex Cross, executive
VP and chief operating officer; Jim Chapman, VP of manufacturing;
and Bruns, VP for engineering. They decided to design and build
an Indy car, but needed a successful CART team as a partner.
Dan Gurney's All American Racers organization had shown everyone
how difficult it was to design a new car without current data
from a good driver in a competitive car.
Swift partnered with Newman-Haas racing and began to design
an Indy car. The project bore fruit when Michael Andretti won
the first CART race of the 1997 season at Homestead, Fla. driving
the new Swift 007.i.
In April of 1998 problems with Newman-Haas forced a reorganization
at Swift that elevated aerodynamicist, Mark Handford, to Technical
Director. Bruns left Swift and went to work for Dan Gurney's
All American Racers as Chief Designer. The latest mods to the
AAR Eagle show Bruns' influence.
The fairing in front of the rear wheel is interesting. Tires
on open-wheel cars create large flow fields that cause a lot
of drag. This fairing is similar to one on Dallara's IRL car.
The team keeps it covered in the pits so there are no detail
photos. I've heard there are some interesting features inside
the side pods but a request to see that received no enthusiasm.
This photo shows a curved gearbox cover that continues the
shape of the diffuser. The most interesting feature is the exhaust
opening high on the engine cover seen just to the right of the
left end plate on the rear wing.
This view shows the exhaust opening just under the rear wing.
I asked Bruns if he had placed both the turbo exhausts and exhaust
from the two waste gates in this high position. He said only,
"Yes." The smaller opening on the right side of the
engine cover might exhaust the right-side waste gate while the
larger opening on the left is the main turbo exhaust plus the
left-side waste gate.
This rear view of the Reynard driven by Tony Kanaan shows
the main turbo exhaust exiting over the left side of the diffuser
where it might, under certain conditions help diffuser flow.
The waste gate outlets are on each side of the diffuser and this
is the space Bruns gains with his design. In the Eagle photo
above you can see the sides of the diffusers are clean and there
is more distance to the tire. The rules state the diffuser must
be a maximum of 35 inches wide and 4 inches high. The tires have
to clear the bodywork by 4 inches.
Current CART rules have been in place for several years and
all the big gains have been made by the chassis engineers and
teams. Small, expensive gains are all that's left. I think Bruns
is exercising his mechanical packaging expertise here placing
components in smaller spaces allowing a more extreme "coke
bottle" shape at the rear. This leaves more room for the
air flow around the rear tires lowering drag and providing less
turbulent air to the rear wing.