Just the relevant parts of the update for BoP adjustment.
Ford GT - 2017
2018 Season 4 GTE BoP Adjustments: Engine power has been increased slightly for better acceleration. Slightly reduced aero drag at low rear wing angles. Fuel fill rate has been updated to equalize fuel fill times during pit stops.
Adjusted sounds for backfires and pneumatic shifting.
Porsche 911 RSR
2018 Season 4 GTE BoP Adjustments: Gear ratios have been opened to match the other GTE cars, slightly reduced downforce at high rear wing angles, reduced engine torque, and adjusted aero slightly. Fuel fill rate has been updated to equalize fuel fill times during pit stops.
Suspension and masses have been updated to prevent roll-overs at curb strikes with low track temperatures.
Baseline setup has been updated with a gear stack built for the transition to open ratios.
I hope to be slightly more competitive this season in the Ford.
There seems to be a possible Ferrari GTE update as well. Focusing on the term 2018 S4 Ferrari 488 GTE BoP Adjustments (Listed under Ferrari 488 GT3)
Ferrari 488 GT3
[li]2018 Season 4 GTE BoP Adjustment: Aero downforce has been increased slightly. Fuel fill rate has been updated to equalize fuel fill times during pit stops.[/li]
[li]Gear ratios have been modified to include the real-world homologated gear ratio stacks: FIA, IMSA Daytona, and IMSA Short.[/li]
[li]The Ferrari Challenge gear ratio stack has been added.[/li]
[li]Please note: 1st gear from the real car was not modeled. As such, 1st through 6th in iRacing are equivalent to 2nd through 7th in the real car.[/li]
Looks like Ford and Ferrari get a boost with a Porsche getting a small nerf and new gearbox.