B737 Performance question
With credit to M. Hulshof Boeing 737 Performance Reference Handbook (FAA Edition) Page A-6
V1...A lower density altitude(higher OAT or lower PA) results in less life force which must be counteracted by a higher speed.For the continued takeoff this implies a higher V1, but this will be restricted by the ability to stop in the aborted takeoff case.
VR...A lower density altitude(higher OAT or lower PA) results in less lift force which must be counteracted by a higher speed, therefore VR needs to be increased.
V2...A higher OAT or higher PA result in LESS thrust, hence less acceleration capability. To keep the T/O Distance Required within the T/O Distance Available, V2 must be lowered. In the combined effect in ISA(higher PA with lower OAT and vice versa), the influence of PA is much more significant than the influence of OAT.
Again, not pitching this book, but more information than a body should know(both FAA and ICAO versions)
Cheers
Vark