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We've
also learned a great deal about oil systems on the dyno;
we now know what it takes to maintain steady oil
pressure over a wide range of engine speeds.
Our dyno
testing procedure for a drag racing engine is to
accelerate the engine at 600 rpm per second under load.
We decided on this acceleration rate because it
simulates what the engine experiences in high gear on a
quarter-mile run. By running a 1500 rpm sweep with an
acceleration of 600 rpm per second, the duration of the
test is 2.5 seconds, which is about the time required
for a Pro Stock to run the "back half" of the
quarter-mile. When we test a circle track or an
endurance racing engine, we use an acceleration rate of
100 rpm per second, which more accurately duplicates an
engine's typical duty cycle on a speedway.
When Buddy Morrison and I started our business 27 years
ago, virtually no one who built drag racing engines had
access of a dynamometer. Now they are almost universal.
Like flow benches and onboard computers, the
proliferation of dynamometers has intensified the
competition in the sport. Before the advent of dynos and
data recorders, a driver who had a good "feel"
for the car or a builder who had an innate understanding
of engines had an |
advantage.
Dynos, flow benches, and data loggers have dramatically
expanded the pool of knowledge in drag racing - and
knowledge is power in our sport.
Dynamometers
that were once used exclusively for power development
are now used routinely for reliability testing as well.
When I go to a weekend bracket race at Kennedale
Raceway, I'm amazed by how many racers know exactly how
much power their engines make. That's because the
majority of racers in the fast brackets have had their
engines on a dyno. Even the guys who build their own
engines recognize the importance of dyno testing. Dyno
testing gives them the reassurance that the ignition
timing is set correctly, the oil pressure is adequate,
and the engine doesn't leak or overheat.
Ten years
ago, a bracket racer might have to make four or five
fruitless trips to the track to diagnose an engine
problem. Now if an engine that ran perfectly on the dyno
suddenly develops a misfire, a racer can concentrate on
fixing the car's fuel and electrical systems instead of
the motor.
The cost of
professional dyno testing is about the same as a pair of
tires. That's a small |
