Lean Tuning Myths

Hi there, I didn´t understand well why endurace cars tend to run leaner for a pitstop strategy. Is this because the car will have a lower B.S.F.C? Sr. Andrew mentionated that these cars can run 0,95 / 0,98 lambda... Is this for full power tuning?

If I have a N/A built engine (block and drivetrain) will I be "safer" in terms of choosing a richer afr for cooling the combustion chamber? If I use 0,84/0,88 lambda in a built engine for cooling reasons will my engine wear down more that a stock one that can´t dispel the heat better?

The time a single pit stop for fuel takes can be longer than the amount of time lost on track from making a little less horsepower.

Optimal AFR for safety, power, fuel economy are generally all different, so AFR selection is a compromise.

As Mike said, it's generally to optimise the pit stops and/or syncronise them with tyre and/or driver changes.

It's one of those "black magic" tasks where tacticians will try and avoid an additional fuel stop which can cost more track time than lapping a few tenths slower. In some cases, like Bathurst 2014, failing to do so can even lead to running out on the last lap, when in the lead, and losing many more places than staying a little off the pace.