During a teleconference on Thursday morning, NASCAR officials announced that the Sprint Cup Series will use the provisional 2017 rules package at Michigan for the Pure Michigan 400 on Aug. 28.
It will be the third race this year to use the package, along with June’s FireKeepers Casino 400 at Michigan and the Quaker State 400 at Kentucky Speedway earlier this month.
As a refresher, the provisional 2017 rules package features a 2.5-inch rear spoiler and the elimination of rear skew. In addition, the rear-deck fin is cut in height in order to match the shorter rear spoiler. The front splitter is smaller than normal. Finally, there are modifications to cooling fans to prevent their use in the development of ground effects. The overall goal of the package is cut the amount of downforce and sideforce that Sprint Cup cars generate.
So far in the two races in which it has been used, the rules have opened the races up to additional side-by-side racing. The rules put a little more control in the hands of the driver as opposed to car setup being king. However, in the case of Michigan, it did not result in the widening of the groove.
Michigan’s Sprint Cup event is being used as an experiment once again. The last two Cup races at Michigan have featured alternative rules packages for evaluation. In addition to the 2017 package being used in June, last year’s Pure Michigan 400 was the second race to use the high-downforce rules package with taller spoilers and fender extensions. The result was a situation in which it was very difficult to pass.
A side effect of the rules was the near-complete sealing off of the cars, leading to high in-car temperatures. NBC Sports installed a digital thermometer in Casey Mears‘ No. 13 GEICO Chevrolet prior to the race as well. Mears only lasted 51 laps before the engine overheated, but a reading of 155 degrees at the level of Mears’ headrest was indicated on the thermometer at the time Mears retired from the race. In-car temperatures closer to the footwell could very well have been close to 170 degrees.
About the author
Phil Allaway has three primary roles at Frontstretch. He's the manager of the site's FREE e-mail newsletter that publishes Monday-Friday and occasionally on weekends. He keeps TV broadcasters honest with weekly editions of Couch Potato Tuesday and serves as the site's Sports Car racing editor.
Outside of Frontstretch, Phil is the press officer for Lebanon Valley Speedway in West Lebanon, N.Y. He covers all the action on the high-banked dirt track from regular DIRTcar Modified racing to occasional visits from touring series such as the Super DIRTcar Series.
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