Q: How do turn rate consoles and other turn boosters work? I don't seem to get the turn rate I expect?
A: Modifiers from the relevant skill and modifiers from the consoles are added seperately and based on your ships base turn rate. So if your ship has a base turn rate of 8 and your skills raise this to 11, a 30 % turn rate buff from a console or a BO ability would not increase it to 14.4, it would only raise it to 13.4.
A ship with a base turn rate of 8 (which would have to be one of the Excelsiors), raised to 11 by skills, and given a 30% RCS Accelerator will have a turn rate of 12.5 degrees per second, not 13.4.
After extensive testing across multiple characters, multiple ship types, and multiple grades and rarities of RCS Accelerators, I have determined the following formula for how RCS Accelerators work.
(Base Turn Rate - 3) * RCS bonus percentage = RCS Accelerator bonus in degrees per second.
Where does the 3 come from? I don't know, but the math works.
The fastest turning Starfleet vessels (my apologies to the KDF, but I have not tested Klingon vessels yet) are the Tactical Escort and Tactical Escort Retrofit. They have a Base Turn Rate of 17 degrees per second.
The best RCS consoles currently available give +35% turn rate.
(17 - 3) * 35%
= 14 * 35%
= 4.9 degrees per second
The slowest turning Starfleet vessels are the Galaxy-class based ships (Exploration Cruiser, Exploration Cruiser Retrofit, and Dreadnought Cruiser). They have a base turn rate of 6 degrees per second. That 3 degree per second penalty before calculating the bonus literally halves the expected return of an RCS Accelerator.
(6 - 3) * 35%
= 3 * 35%
= 1.05 degrees per second
As MustrumRidcully indicates, RCS Accelerators are added seperately. There are no diminishing returns on them: each additional console uses the same formula, working from the same numbers, giving the same gain.
Following from that, if a Galaxy-class based ship used all four of its Engineering Console slots on +35% RCS Accelerators, the net gain would be 4.2 degrees per second... less than a Defiant gains for a single console of the same type.
The ship that can improve its turn rate the most via RCS Accelerators is the Fleet Escort. It's base turn rate is lower than that of the Defiants, but it has an additional Engineering Console slot. A Defiant can gain a maximum of 9.8 degrees per second (two +35% RCS consoles at +4.9 degrees per second each), whereas a Fleet Escort can gain a maximum of 12.6 degress per second (three +35% consoles at +4.2 degrees per second each).
I might remove mine off of my Advanced Escort, since even it doesn't seem to benefit from it as much as would make it worth it, now for another engineering console that is worth it... or maybe move a universal console there and gett more healing power.
What about the effect of the Turn modifier on an engine?
That I haven't figured out yet. It's going to be trickier, and much more expensive, so it might take me a while. Or, like another problem I tried to figure out (armour consoles), it may prove too complex for me.
While I still haven't done any actual testing over on the Klingon side, let's assume for the moment that the formula works the same over there. We have no particular reason to believe it doesn't.
From that basis, again, the extremes of the KDF ships...
The fastest turning starship in the KDF armada is the B'Rel Bird-of-Prey and its T5 refit, blowing away the Tactical Escort's 17 degrees per second with a base turn rate of 23 degrees per second.
(23 - 3) * 35%
= 20 * 35%
= 7 degrees per second
The slowest turning vessel in the entire game is the Klingon Vo'Quv carrier, with a sub-Galaxy-class turn rate of 5 degrees per second.
(5 - 3) * 35%
= 2 * 35%
= 0.7 degrees per second
That's right, the B'Rel gets literally ten times as much benefit from RCS consoles as the Vo'Quv does. A B'Rel refit devoting all of its Engineering Console slots to RCS Accelerators would nearly double it's already (almost) best-in-game turn rate. Three consoles at 7 degrees per second each, for an additional 21 degrees per second. Even before skills are taken into account, that's 44 degrees per second.
The poor Vo'Quv, devoting all of its Engineering Console slots to RCS Accelerators would gain a measly 2.1 degrees per second of additional turn rate.
Of course, the B'Rel actually ISN'T the fastest turning craft in the game; it's just the fastest starship. If we look at fighters and shuttlecraft, they turn even faster.
The slowest turning shuttle in the game is the Tal'kyr Vulcan Support Craft. Yet it matches the turn rate of a Fleet Escort, with 15 degrees per second.
(15 - 3 ) * 35%
= 12 * 35%
= 4.2 degrees per second
For the fastest turning vessels in the game, you have to go to the C-Store and grab the fighters. Despite their rather different looks, the Starfleet and KDF fighters are mechanically identical, and have a 33 degree per second base turn rate.
(33 - 3) * 35%
= 30 * 35%
= 10.5 degrees per second
...luckily those little fighters can only cram in one RCS Accelerator, or you might find that you were doing 360s every time you tried to turn...
Of course, RCS Accelerators are probably the easiest part of the turn rate picture to figure out, unfortunately. In addition to these optional consoles, your Base Turn Rate is modified to varying degrees by your Engine, your Engine Power, your throttle, and up to five skills (if I'm remembering correctly). That's a lot of variables to account for, crammed into a relatively small number. Still, I'll see what I can do, and encourage others to try it themselves.
For everyone's information, I found out that the +7.5 Engine Power of the Breen Engine provides just slightly less of a turn boost than a [Turn] modifier, at least on my Galaxy-X.
Breen Engine is effectively [Turn][Aux] +Engine Power, and it provides 0.1 degree less turn than an MK X [Turnx2] Engine (got via explore). I figured the 0.1 degree less is worth the Aux modifier (I'm using dual cannons on the Gal-X, so I am trying to get my turn rate as high as possible).