GM Simulates Indy 500 on Dyno

Contact: Rick Voegelin
rickvoegelin@compuserve.com
GM Racing Communications
(831) 761-2201
                            
(Note to Editors: A chart of the Indy 500 dyno simulation program is
available in Microsoft Excel format on request.)


Relentless Engine Testing Is a Dress Rehearsal for Indianapolis 500

DETROIT, May 15, 2001 - GM Racing engineer Scott Peterson has never turned
a lap on Indianapolis Motor Speedway, yet he has completed dozens
of Indianapolis 500 races. Peterson's "race car" is a computer-controlled
engine dynamometer that can precisely simulate a complete 500-mile race.
Peterson and his colleagues relentlessly dyno test Oldsmobile IRL Aurora V8
engines to ensure that they can withstand the stresses they will encounter
in the Memorial Day classic.

    "Our primary goal is to make sure that every part in the engine can go
500 miles," said Peterson. "We put more pressure on the components than
any driver. When we come up with a new design for a camshaft, piston,
valve spring, or any other part, we put it through a 500-mile durability
test. If it survives and passes inspection, the new piece becomes part of
the GM engine kit."

    A dyno cell is a torture chamber for racing engines. Not even
thick concrete walls and double-pane safety glass can muffle the scream of
an IRL Aurora V8 running on its 10,700 rpm redline. Shackled with wires and
probed by sensors, the engine is pushed to the limits of its endurance.
Peterson, 27, is the taskmaster who oversees these engine torture tests.

Computer program recreates Indy 500

    Peterson conducts his race simulations at Katech, Inc., GM
Racing's development partner in Clinton Township, Mich. As the computer
automatically regulates the dyno, it is easy to visualize the engine speed
climbing as the car streaks down the straightaway and falling as the tires
scrub off speed in the corners. Occasionally the computer lifts off the
throttle as the phantom driver encounters traffic, and then runs wide open
again on a clear track. After 32 exhausting cycles (the equivalent of 80
miles on the 2.5-mile speedway), the computer gives the engine a brief
respite during a simulated pit stop while technicians connect a fresh drum
of fuel.
 
   "The data for the simulation program came directly from a qualification
run at Indy," Peterson explained. "There are 55 distinct steps as the
engine accelerates and decelerates. These steps represent the aerodynamic
and mechanical forces that affect the car. The test schedule is the
equivalent of running a 41-second lap at an average speed of 220 mph.

    "The dyno simulation is more demanding than any race because there are
no caution periods that allow the engine to breathe," Peterson noted. "The
dyno simulation subjects the pistons, rod bearings and piston pins to loads
that are much higher than they experience in an actual racing environment."

Testing enhances GM's winning record in IRL

    The benefits of this rigorous testing are apparent on the
racetrack. Oldsmobile engines have won 40 of 41 races (including four
straight Indianapolis 500 victories) since the Indy Racing League
introduced its naturally aspirated engine formula in January 1997.
Durability tests have also dramatically improved reliability; Oldsmobile
engines have completed more than 200,000 racing miles in IRL competition.

    "The testing program also validates the quality of parts we
have previously released," Peterson continued. "When we are testing new
pistons, for example, we are also testing the crankshaft, the timing
chains, and every other part in the engine. In the last 18 months, GM
Racing has tested 35 motors and completed thousands of miles of simulated
track tests."

    Racing also benefits young GM engineers like Peterson. After he
completes a two-year "tour of duty" with the IRL program, Peterson will
return to GM Powertrain's advanced engineering group to design engines for
future GM cars and trucks. He will take with him a thorough knowledge of
high-output powerplants and an innovative approach to problem solving.

    "Racing has taught me the value of rapid engineering," Peterson said.
"An engineer has to do the job right the first time on a racetrack. I've
learned what it takes to make horsepower and torque, while on the
production side we have to focus on fuel economy and emissions. Running the
Indy 500 dyno simulation program has been a real education."

    GM Racing's commitment to continuous improvement has given
Oldsmobile's IRL Aurora V8 the power, stamina and reliability that have
made it the dominant powerplant in the IRL. Peterson will continue his dyno
testing program until the green flag flies on May 27. Even when the IRL
Aurora V8 racing engines at the famed speedway are silent, other Oldsmobile
racing engines are screaming in a dyno cell in suburban Detroit.

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  E-mail from: Rick Voegelin, 15-May-2001