All Prototype cars will restart ahead of GT Le Mans and GT Daytona class entries, as one of several changes made to the sporting regulations for the IMSA WeatherTech SportsCar Championship next year.

IMSA has created the ‘Prototype Class Split’ for 2018, which will see GTLM and GTD cars pull to the left side following the final wave-by to let the entire P class field restart ahead of the production-based classes after each full-course caution.

The procedure, which had been utilized in Grand-Am, comes after multiple incidents or near-misses in recent years as a result of a class leader, oftentimes in a slower category, taking the field back to green and causing a bottle neck-like effect.

The final restart in last month’s Motul Petit Le Mans saw the GTD class-leading Land Motorsport Audi R8 LMS lead the field to the green and ultimately trigger contact between the two Action Express Racing Cadillac DPi-V.Rs behind it.

A number of other similar situations were also seen throughout the season.

In another change for 2018, GTLM cars will be allowed to pit alongside Prototype entries on the first lap of the pit lane being declared open while under caution.

Previously, Prototype cars had pitted, followed by GTLM and GTD cars together the following lap.

Changes in Qualifying Rules

IMSA, meanwhile, will prohibit any form of modifications or touching of the cars while during qualifying, once the car leaves its pit box for its run.

Drivers must remain in their cars until they arrive in impound post-qualifying, unless in the case of each pole-sitter, who may be directed by an official to exit the car for interviews and to participate in the Motul Pole Award photo.

Additionally, teams will no longer be required to start on their qualifying tires, and any GTLM car sent to the rear of the field will now line up at the back of its class, and not behind the entire GT grid.

One Manufacturer Change Per Season

Teams will now only be allowed to change manufacturer or constructor once per season, subject to force majeure and at the sole discretion of IMSA.

The rule comes following WeatherTech Racing’s mid-season switch from a Mercedes-AMG GT3 to a Porsche 911 GT3 R this year, and having considered moving back to the Mercedes over the remainder of the season.