Welcome Grub! Here's what I do:

Frontrunners:

6-8F - Whip at the 1.7 mark
9-11F - Whip at the 2.0/2.1 mark
12+ F - Whip at the 2.3 mark

Preceders/Mid-Packers:

Turf
6-8F - Whip at the 2.7 mark
9-11 - Whip at the 2.8 mark
12+ - Whip at the 2.9 mark

Dirt
6-8F - Whip at the 2.3-2.4 mark
9-11 - Whip at the 2.5-2.6 mark
12+ - Whip at the 2.7 mark
(dirt is tougher for me with preceders)

Not sure about closers.

Good Luck.