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.” […]

Cooling

Engine Issues at Talladega: Vapor Lock, Gas Cans and Oil Coolers

An usual number of teams “ran out of gas” or had engine troubles during the Talladega race. The TV analysts had some ready answers for what might have caused these problems. Their extemporaneous theories tend to elicit sighs from engine builders, who know that problems can rarely be diagnosed at the track – and even more rarely by someone who hasn’t looked at the car.

A wonderful aspect of blogging is that we’re not called to have answers on the spot like the television broadcasters and we have the leisure of time. Let’s examine some of those theories. […]

Cooling

Plate Racing Rules: Getting Ready for Talladega

Most of the issues we were talking about at the start of the year regarding the measures NASCAR has taken to eliminate or reduce the two-car draft are still in play, so I thought I’d put the most important in one place as you start getting ready for Talladega this weekend. […]

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? […]

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. […]

Bristol Motor Speedway

Bristol: Banking

Bristol Motor Speedway made its name as a high-banked short track, but Bristol banking has changed over the years. Bristol Motor Speedway announced that they are grinding down the upper groove of the track to […]

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.) […]

Andy Randolph

Kansas: Temperature and Horsepower

There were a lot of engine problems at the Kansas race last Sunday. Also, a lot of theories as to why there were a lot of engine problems. Let’s start with the cooler-than-expected temperatures. […]