Read an article from So. Carolina newspaper that was from Daytona July race. Could give more insight into Chevy being behind. Quotes from reporter:
"Chevrolet designed the Camaro to take advantage of NASCAR's previous inspection system of templates.
But NASCAR switched to a more precise scanning system this year, which erased some of Chevy's expected gains. Ford, especially those at Stewart-Haas Racing, improved the most from the change in inspection procedures.
Adding to Chevy's woes, NASCAR began enforcing a rule that requires front splitters to be completely flat. That tweak changed aerodynamics and caused the Chevrolets to plow through turns more than before.
Teams had been allowed to make their own splitters in previous years, and Toyota had been the biggest beneficiary of that rule in 2017. The Japanese automaker won 16 of 36 races, including the championship, last year."
"Chevrolet designed the Camaro to take advantage of NASCAR's previous inspection system of templates.
But NASCAR switched to a more precise scanning system this year, which erased some of Chevy's expected gains. Ford, especially those at Stewart-Haas Racing, improved the most from the change in inspection procedures.
Adding to Chevy's woes, NASCAR began enforcing a rule that requires front splitters to be completely flat. That tweak changed aerodynamics and caused the Chevrolets to plow through turns more than before.
Teams had been allowed to make their own splitters in previous years, and Toyota had been the biggest beneficiary of that rule in 2017. The Japanese automaker won 16 of 36 races, including the championship, last year."