Aerodynamic Forces

The Myth of the 200-mph “Lift-Off Speed”

The speeds at Pocono were high, but the speeds at newly repaved Michigan are even higher. Nine drivers posted lap times over 200 mph on Thursday, leading to media and driver hysteria about the high speeds. What is the lift-off speed at Michigan? […]

Bristol Motor Speedway

The Reason for Decreasing Cautions

This was the first year that most people noticed a decrease in the number of cautions, but (as I’ve pointed out), 2012 is merely the latest in a six-year trend of decreasing cautions. The same downward trend is evident in the Nationwide Series. This year is perhaps notable for it being so extreme.

The data clearly shows the trend: The question, of course, is why?

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Aerodynamic Forces

Aerodynamic Downforce: A Passing Fad?

The question of why it is so difficult for cars to pass each other at 1.5 mile and 2 mile tracks is getting more and more attention. Carl Edwards put it succinctly:

“I firmly believe, and NASCAR hates it when I say this, that we should not be racing with downforce, sideforce and all these aerodynamic devices. We do not need splitters on the race cars and giant spoilers. I have not been around long enough to say something definitely, but it is pretty common sense: if all the cars are very similar and all the drivers are within a tenth of a second of each other but are relying on clean air and downforce, then by definition if the guy in front of you is disturbing the air then your car is not going to be able to go as fast as it could in clean air.” […]

Edwards, Carl

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 […]

Richmond

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? […]

Cautions

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.) […]

Cautions

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. […]

Electronic Fuel Injection

How close is NASCAR EFI to “Real” EFI?

As we turn on the (new) engines to start the season, the twitterverse is getting even more full of people debating the NASCAR EFI system. Is it like the EFI in production cars? Is it throttle body? Is it multiport? Here are the answers: […]

Electronic Fuel Injection
Busch, Kyle