Archive for Month: April 2012
Richmond Redux: Relative Velocity
NOTE: Some clarifications added 1:00 p.m. 4/30/12. Thanks to all the commenters, especially @nateryan! I think Dave Moody did a good job breaking things down. The situation is confounded because there were so many different complications. Who from NASCAR is duly authorized to tell a spotter/crew chief/driver their position? Is […]
Is More Data Always Better?
Saturday’s race in Richmond was a festival of miscues. Carl Edwards mistakenly thought he was leading, then he jumped the restart, although he wasn’t the one to lead the restart because he wasn’t the leader. One would think we have the data that could prevent incidents like this. We probably do. But do we want to use it?
Infographic: Bristol: Old, New and Newer
In response to requests about how the ‘new new Bristol’ compares with the ‘new Bristol’ and the ‘old Bristol’, here’s a comparison. For more on the changes, see my earlier post. The light blue triangle shows the constant 36-degree banking of the ‘old Bristol’. The black line shows the progressive banking (24-30 degrees) that was introduced in 2007 and the red line shows how (I think) they are modifying the highest groove only. Note that there seems to be some disagreement about the actual banking values. I’m using the values the track uses.
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.
Bristol: Banking vs. Distance
Bristol Motor Speedway announced that they are grinding down the upper groove of the track to decrease the progressive banking. My (to-scale!) sketch of what I think they are doing from the press conference and the tweets (thank you so much Nate Ryan!) is below. The 2007 re-do introduced progressive […]
Cautions: A Historical Downward Trend Over the Last Six Years
Being the data geek that I am, I was really curious if the decreasing number of cautions was specific to this year. It’s not: Cautions have been decreasing since 2005,as the graph below shows. The squares are the cumulative number of cautions per 100 miles, obtained by adding up all the cautions in a season and dividing by the total number of miles in the races. (This is a more accurate number than total cautions, given rainouts, shortening races and different venues from year to year.)
Kansas: Temperature and Horsepower
There were a lot of engine problems at the Kansas race last Sunday — and a lot of theories as to why there were a lot of engine problems. Let’s start with the cooler-than-expected temperatures on Sunday. When the air temperature changes, so does the number of air molecules heading […]
Why You Can’t Predict Anything Based on the First 10 Races
The plot below shows the cumulative number of cautions per mile since 2007. I’m using number of cautions per100 miles to 1) make up for races that were not run to completion; 2) compensate for green-white-checkered finishes; 3) compensate for tracks that have shortened races; and 4) compensated for changing […]
Are Cautions Really Going Down?
I honestly cannot help it – scientists are naturally skeptical. If you make an assertion, I will have to question you on what data you have that supports it. This is second nature to the people I work with, but I realize it is damned irritating to non-scientists (aka “normal”) people.
So when I started reading everywhere that “cautions were down 35%”, I had to go look into it. This is a preliminary post – more detailed analysis will follow as soon as I’ve read my students’ final projects and gotten comments back to them.