Quote:
Originally Posted by corgatag
I don't have the game in front of me to check, but if someone else does here's how to get the numbers:

Tested with a Standard White Mk XII Quantum Torp
Unslotted Damage: 3342 (393 DPS)
Base Slotted Damage: 4830 (568 DPS)
(with Weapons Training 9 and Projectile Weapons 9)
** Damage Numbers by Skill **
Base Slotted Damage: 4830
with TS3: 2848 x4 = 11392 (Max 5 Targets)
with TS2: 3330 x3 = 9990 (Max 4 Targets)
with TS1: 4303 x2 = 8606 (Max 3 Targets)
with HY3: 3560 x4 = 14240
with HY2: 4163 x3 = 12489
with HY1: 5378 x2 = 10756
** Best Damage versus 1 Target, in descending order: **
HY3: +194.82% of Base Slotted Damage
HY2: +158.57% of Base Slotted Damage
TS3: +135.86% of Base Slotted Damage
HY1: +122.69% of Base Slotted Damage
TS2: +106.83% of Base Slotted Damage
TS1: +78.18% of Base Slotted Damage
Obviously, Spread attacks are ALWAYS better if you have more than one foe in your 90' torpedo arc.
However the damage can really start to skyrocket with Spread attacks if enemies are tightly clustered together (to stack up splash damage). Unfortunately splash damage is only really applicable in a few limited situations, since it requires ships to be very close together  within 300m of each other to see any benefit. The most common realgame examples of this will include fighters, probes, and anything you've bunched up with a Gravity Well.
Note also that:
(i) The more tightly bundled your foes are, the higher the damage numbers will rise  the torpedo explosion AoE is only 300m wide and splash damage drops off linearly  so a ship sitting 75m away will get 75% of the normal explosion damage, 150m will get 50%, etc.
(ii) Each HY powers is EXACTLY 1.25 times the damage of the sametier TS power versus one target.
(iii) Moving from HY2 to HY3 or TS2 to TS3 is a slightly higher damage increase than moving from HY1 to HY2 or TS1 to TS2.

Stacking Other Buffs
Using Tactical Team grants a buff to "Projectile Weapons" which increases damage slightly (approx an extra 2.8% for me  varies very slightly from 2.79 to 2.81 which is probably due to rounding).
** Numbers with Tactical Team 1: **
Normal slotted damage: 4965
with TS3: 2928 x4 = 11712
with TS2: 3423 x3 = 10269
with TS1: 4423 x2 = 8846
with HY3: 3660 x4 = 14640
with HY2: 4279 x3 = 12837
with HY1: 5529 x2 = 11058
Using Attack Pattern Omega grants a flat damage buff. This gets applied against your standard slotted damage AFTER skills are applied... so if you use both Tactical Team 1 and APO1, Tac Team 1 raises your damage by buffing your projectile weapons skill, then APO1 grants you 115% of this (already increased) base damage.
The upshot is that you'll get more damage than you'd expect.
An example of this multiplicative damage stacking with real numbers:
+ TS3 (by itself, 0 buffs): 11392 "standard" damage
+ TS3 with TT1 (+PW Skill): 11712 [an extra + 2.81% of standard]
+ TS3 with APO3 (+ Damage): 14220 [an extra +24.82% of standard]
+ TS3 with both TT1 + APO3: 14616 [an extra +28.30% of standard]
Basically, make sure you have Tac Team running whenever you fire off your other damage buffs... it'll give your torps a little extra "Oomph".

TL;DR version:
+
Stack your buffs (nothing new here)
+
Take HY over TS only if you need to damage one thing at a time. (This rules out a lot of roles in endgame PvE, eg STFs with Kittomer probes, Kang attack waves, and Nanite Spheres  but HY will usually be quicker at killing single big targets like Tac Cubes and Structures)