In combination with tiny/smull hulls, and if it's TA some HP modules on them to maximize firstly firepower and secondly survival rate, that's actually a very good suggestion.

You might also consider (in TA only) using an Atlas module and either one or zero weapons on a huge hull, filling up the rest with defenses, and fleeting it up with enough tiny or smalls (full of weapons but an hp mod or two couldn't hurt) to hit your logistics cap.  The Atlas module makes the huge hulled ship the primary target, so you don't lose any tinies, and with maxed out defense, it should take a while to die to even 25 fleeted pirate ships.

Your other option would be suicide dreadnaughts, all attack/no defense in fleets of one.  Due to how combat works in DA and to a lesser extent TA, in a large number of instances fleets don't actually help you, and I'm fairly positive this is one of those situations.

Quite some time ago I had a Peacekeeper event where they were roaming the galaxy in fleets of 15-20 ships, with each ship at 400 beam attack/1400 beam defense, but I eventually managed to defeat all of them, simply because they don't get reinforcements.

Military starbases won't help you in this situation. They work best when you can have hundreds of tiny ships, and you simply don't have the time to do that.

Don't waste your time on defenses. Your ships aren't going to survive anyway, so give them as much punch as possible. Same thing with engines and life support - don't worry about it. Just put as many weapons on there as the ship can hold.

The other alternative is running. Build really fast ships - those pirates are probably quite slow. As long as your ships aren't in range to be attacked at the end of your turn, you will be fine.

Or you could try for a tech victory.

@Dragoonkin

At least the pirates can't invade you.  If they could, now that would be broken.

Also, for the record, this is the MEGA pirate event we're talking about here, for which you need to have MEGA EVENTS turned ON to see.  In other words, if you can't deal with it, you might consider turning them OFF.  The normal pirate event doesn't spawn fleets of more than 4 or so ships a piece, although there are still a significant number of fleets-nor are they anywhere as strong.

I gave up on them you just can't take them out. I was doing a NON tec win so with out killing the other races just could not end the game.

So I switched to trying out Dark Avatar and none of those pirate problems are in there at all. There are less pirate ships and what does show up you can take out like other normal fleets. So I guess it is just a bug with the Dread Lords add on.

Thanks for the help though guys it is apreciated from this new guy.

Although did run into a problem with the minor races in Dark Avatar. Invisable ships that only show up as a number when it is a fleet. My Guard ships can detect them and go after them but if one of my fleets fight them the game crashes. If a single ship fights them it shows a battle screen but just my ship and no shots fired then it shows a win and you end it. All of the construction ships they send are invisable but the star bases they create are visable. It is strange to say the least.

Yeah that pirate mega event is nasty, but I've never had it where they were that powerful.  The best pirate fleet I've seen was one with off-scale missile defense and I think 800 missile attack, along with 500 total HP or so and a speed of 7 (I think it was five ships).

As for how to deal with them, well... I'm not sure.  Perhaps you should let your military temporarily die and hope they move on before your neighbors get greedy.

I have to disagree here.  The game raises certain expectations of 'fairness'.  Not that there is a level playing field, but that the numbers you're playing with are relevant.  There are resources that can be utilised within limits.  The mega pirates break those limits without any rational explanation.

The mega pirates event is broken because it breaks the rules.  Some pirates appear from nowhere - fine.  That more ships appear than have been created in the universe up until then by at least an order of magnitude is ridiculous.  That they can disregard the rules that everyone else has to abide by - fleet size, speed etc. is silly.  The game looses suspension of belief.  Beating the pirates wasn't fun for me - it was a tedious operation of mopping them up.  Loss of belief, loss of fun - mega pirates are broken in terms of game.  When they show up, you don't win because you're a better strategist, you win because you grind them down (or just abandon the pretence of playing a 4X game and grind your way to a tech victory).

Now if you can come up with a better explanation for them being there and behaving the way that they do than 'magic', I'll be more supporting of them.  A little.