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Aerodynamic Forces

How Fast Would NASCAR Cars Go at Daytona without Restrictor Plates?

Doug Yates was guest on Dave Moody’s SiriusXM Speedway last week. He brought up a conversion you hear a lot in the week before Daytona and Talladega. Every 25 horsepower in the engine translates to about a 1 second decrease in lap times. Dave did the math: Removing the plates would increase the engine by 450 horsepower. Four hundred and fifty more horsepower equates to 18 seconds off the lap time, assuming all other things equal. That last part was a very important qualification. It will come back to haunt us in a moment. […]

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Engines

Eliminating Restrictor Plates?

Every return to a restrictor plate track brings suggestions about how we might eliminate the restrictor plate. Restrictor plates serve the very necessary function of limiting car speeds at Daytona and Talladega so that the cars stay on the ground. The negative is that they remove throttle response. One suggestion from some readers that I hadn’t heard of before suggested that NASCAR could just change the rear-end gearing parameters to shift the power curve and reduce horsepower that way. Will that work? […]

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Andy Randolph

Kansas Wrap Up: What Caused all the Engine Failures?

The defining characteristic of the Kansas race was the surprising number of engine problems. Many of those problems can be attributed to the change in rear gear from a 3.89 to a 4.00. At 190 mph at a track like Kansas, your wheels make 2270 revolutions per minute (rpm). If you watch the telemetry on the television broadcast, you know that the engine is rotating around 9500-9900 rpm. Since the engine is attached to the wheels, there has to be something to change the rotation rate between the engine and the gears. […]