[djdodo]

Save Your Game in Port.
Goto \Docs and Settings\SH4\data\cfg\SaveGames
Take the last folder, save-copy it to another location (Important!)
Open ActiveUserPlayerUnits.upc
Look for:
[UserPlayerUnit 1.Compartment 1.WeaponSlot 1] and for
[UserPlayerUnit 1.Compartment 1.WeaponSlot 1.Weapon]
Here you can change e.g.
IDLinkWeaponLoaded=TorpedoTube21inUS, Mk14Torpedo ->
IDLinkWeaponLoaded=TorpedoTube21inUS, Mk16Torpedo etc.
and
AmmoTypeLoaded=Mk14TorpUS ->
AmmoTypeLoaded=Mk16TorpUS
Now look for
[UserPlayerUnit 1.Compartment 1.Bunker 1]
and
[UserPlayerUnit 1.Compartment 5.Bunker 1]
Here you change the Capacity to what you like (be serious, 100 is too much)
Here you say what to load:
IDLinkAmmunitionLoaded=Mk16Torpedo,30
or
IDLinkAmmunitionLoaded=Mk16Torpedo,10,Mk14Torpedo, 20

Not a mod, but it works.