OP Terran Tachi. 

You don't need to start a new game.
It is enough to simply replace the model from the Tachi mod, sell all the equipped (installed on the ship) equipment and buy/install it again, then everything will get up in a new way.

Now 6 weapons S class, 4 turrets S class, 4 shields S class and 2 rocket suspensions S class + add new turrets firing sound.

Changes:
v2.5 - some fixes. Now Tachi use S turrets from AE mod and my future T.R. mod.
v1.9.1 - 1 S shield removed (bottom).
v1.9 - BrummBear update included + turrets range category fix.
v1.8 - Ware fix price. Now turrets not mandatory component. Turrets damage reduced (I made a mistake, because I didn't plan to make the turrets that powerful.) 
v1.7.5 - Some ship stats corrections. Turret sound fix. It turns out that all the basic sounds of weapons in the game are made in mono, and I originally did in stereo. For this reason my sounds were twice as loud - sorry. =)
v1.7.3 - My falls - fixing launcher pods. Now only Launchers can be installed.
v1.7.1 - Wares fix.
v1.7 - Updated. Now work in 6.0 + some fixes.
v1.5 - Now this is the first ship in X4 with independent rocket suspensions, as it was in X3 (2 rocket suspensions added). S Turret bullet effect was changed, S turrets fire power was reduced.

Original mod here: 
Tachi - Ter S Fighter
+ thx Arazorbladekiss - NYX