Utilities
GPxPerf - Nunziati Matteo and Schubert
GPxPerf allows you to create performance data for GP3. It calculates driver and team performance based on qualifying and race times. This performance data can be loaded into GP3Edit (by Steven Young) and exported into GP3.
Pit Stop Strategy Calculator - Schubert
This excel worksheet calculates and tells you as accurately as possible, which pit stop strategy will work best, based on the track, amount of laps, tyre wear, etc. It also considers the drop in pace due to heavy fuel loads.