Monster Myrtle

As was the case when I used to work for RGM, I took the 600 weekend off and went to Myrtle Beach for the holiday. The 600 is insufferably long and I can never get myself to stay in town for it. And, when your friend has a condo on the beach that he is letting you stay at for free, you go. You just go, and let all the other locals deal with traffic and hullabaloo. I remember two years ago I was at the beach, and I got a call from Robby at about 3.30 on raceday. He says, "Where are you?", and I go, "Uhhhh...Myrtle Beach." Then he says, "Can you get here and do the fuel mileage?" and I go, "No. I already talked to Gene, and he is cool doing it on his own." Yeah. A bit awkward, and I felt bad about it for about an hour. Then I got really drunk and danced with everyone in the beach house, and my chi was restored.

Obviously the big news this week in Robby world was the rear end confiscation and subsequent penalty. So, I guess it is time for a technical discussion about what was wrong, and how it could possibly come to be. First of all, I would like to comment on the penalty. I really thought it was going to be much bigger. After NASCAR threw the book at Carl Long for his minutely oversized engine, I assumed it would be doom and gloom for the 7 car. Especially since you could argue that rear end was probably more blatent and more of a performance advantage than the engine.



It has been vogue for about a year and a half for the Cup cars to run 1/2 an inch of toe in at the LR and 1/2 an inch of toe out on the RR. The picture below shows the difference between a zero toe and 1/2 toe in, toe out car as it drives down the track. The toe does two things, one aero and one mechanical. The aero effect is that the car will crab down the track, and the driver actually has to steer a little bit to the right to keep it pointed straight. The right side of the car is exposed to the air and creates side force (like downforce, except it pushes the car left towards the apex of the corner). The side force gets the car to turn better and keeps it stable. The mechanical effect is that it creates rear steer in the middle of the corner, which helps to alleviate the tight in the center condition that plagues COTs. When a monster truck steers, the front wheels point to the corner apex and the rears, point away from the corner. Rear steer is much more sensitive than front steer, and it rudders the monster truck so that it can go around sharp corners. The same principal applies to the Cup cars, and pointing the rear axle towards the stands steers the rear of the car.




Now, the toe measurement that NASCAR takes is relative to the chassis. There is some adjustment in the axle mounting bushings and the axle can be mounted such that a 1/2" housing can be rolled forward to make a 5/8" housing, or rolled back to create a 3/8" housing relative to the chassis. My suspicion is that the car went through tech, the rear end was measured and was just this side of being legal, and passed inspection. Then, in the race, the bolt that holds the axle mount must have loosened up enough so that it was just barely out of specification when it was post race inspected. So, in effect, this was sort of a similar penalty to a car showing low in post race inspection. Just a consequence of running laps at a track with high cornering loads or bouncing off the wall.

Off to Dover this week, and another track I can sink my teeth into. High banks, fast laps, and good wrecks....MMMM..MMM. Dover is Roush country, and I will pick the 99 to get his first win, with the 16 nipping at his heels. After his strong run at Bristol, I will go for Ambrose for a top 10. This will be the first time in a while the RG will get to qualify the 7 at the first Dover race, as he is usually in Baja. Even with other people qualifying the car, he has done decent here, so I will go for an 15th for the 7.