so after using the FS_Defiant in game i realised the original defiant hp which was used (thats correct right farshot?) was not compatible with my install. I was using her against the LC dominion Romie Warbird (three of them) and i was decimated in seconds.
so i upgraded the defiant with sfrd/sfsy specifications... made things better but i was still out matched which i felt was not how the defiant should be.
rather than changing the Warbird hp i looked at the defiants and decided to test something:
i took the fact it had 2 impulse engines and doubled the speed,acceleration and angular thrust and the angular acceleration. (so it had 18, 18, 1.0,1.0 in the MPE )
it worked great
i was still badly over matched but i did eventually win.... whether this would work with all ships i dont know but it was fun and not stupidly fast