IndyCar teams using the single-turbo Honda engine will be allowed to upgrade to a better unit starting at the Sao Paulo Indy 300 on April 29. Honda wanted to upgrade for Long Beach but a battle over rule interpretation stopped them.
Honda’s single-turbo application apparently spools up slower than Chevrolet’s smaller twin turbos, so the Honda-powered cars accelerate less quickly on street and road courses. The new turbo should help on the Sao Paulo street course.
Because of restrictive engine-modification rules designed by the manufacturers to control costs, Chevrolet was able to block this change until IndyCar reviewed its own rules and decided the upgrade was allowable. Chevrolet won the first three races of the season with its twin-turbo setup and saw no reason to give up any advantage.
Meanwhile two teams are reported to want to end their Lotus motor contracts and switch to Chevys. The Lotus engine has been hampered by underfunding and under-development because the parent company was sold and funds were frozen briefly.