As mentioned by Banryu79, and confirmable on Wikipedia if you type "German T2 electric torpedo" in your search bar, most of the T2's depth keeping and detonation problems were apparently solved by the end of the Norwegian campaign (June 40).

I only state this due to testing of my sphere work in rough weather against warships using a 1942 IXB.
I'm having some trouble testing the reliability of the spheres due to the seemingly excessive pre-detonation, and non exploding magnetics in 42.

So I wonder if anyone would be kind enough to tell me what files control the torpedo failure rates?
It would save me some time searching through files.
I could ( and will ) replace the T2'S with T3's for testing, but as with other elements of this game, I'd rather fix it while I'm tinkering.

Ah well, obviously not then.

That is certainly at odds with the picture presented by Clay Blair (Hitler's U-boat War, Volume I, The Hunters, 1939-1942). According to Blair, sub commanders were still critical of torpedo performance, and Dönitz was still raising the issue with OKM in mid-1941. Blair even mentions reports of circular runs, including one that may have destroyed a boat. In June, 1941, Endrass, a Ritterkreuz holder, reported four failures out of four firings.

Personally I never use T2s. T1s can be fired from further out, go faster, and have never given me problems.

Even if you fire them in plain daylight, from afar (let's say from more then 2000 meters)?
Of course I'm thinking about the telltale wake of bubbles...

I haven't had any problems. Usually the target is not escorted. In those cases where the target is, the destroyers can usually figure out where you are shooting from anyway. I'm almost always broadside to the target. Those extra seconds that it takes the torpedo to hit its target let me get deeper. I usually locate the target by hydrophone, go scope up, click lock, dive, and fire. I am already on my way down before the second torpedo leaves the tube.

I use two torpedo salvos on ships in convoy and only target the biggest ships. I use the slowest speed for convoys. On ships traveling alone, I can usually use a higher speed, especially if I'm unsure about the ship's speed.

Poor choice of words perhaps on my part Bigwalleye.

I was stating the info on Wikipedia, but since people can contribute to the info there it may not necessarily be entirely accurate, especially in comparison to the first hand experience of those who actually used those torpedoes.
May have been better if I replaced the word "state" with "mention".

I'd still like to know where the failure rate can be tweaked without fishing through hundreds of files though, if anyone knows?

If you have h.sie's patches installed, look in your game folder for a file named hsie.ini. Open it in Notepad (or your preferred text editor) and scan down until you find:

I've never tried changing the settings, so I don't have a recommendation. If you find settings you like, please do post here and share your results with the community. Thanks.

I'm assuming that you have h.sie's patches installed. If you don't, then I urge you to get both h.sie's and Stiebler's path kits and add them. Together they add about two dozen great improvements to the game.

I don't have any of h.sie's patches.

I don't like to download other people's work, having decided to walk away from these forums some years ago, with the intention of never participating again, or releasing any of my own mods.

Exceptions to that were GWX3, torpedo damage final v2, and lifeboats & debris v4, which I had before leaving, and "The DarkWraiths ejecting pilots", "Widescreen_GWX3" and "LSH3", specifically so I could nick the Yamato and Strasbourg to add to my game.
There are probably some others I had before I left, but those mentioned above are the only ones I use.

Recently I started testing an existing mod ( of mine ) specifically in heavy weather, but I found the failure rate of the torpedoes was making a mockery of the tests, so due to lazy-itus really, I've chirped up again.

In doing so it has not been my intention to hijack anybody else's thread, I simply found an existing thread on the subject to ask a question.

It was a mistake to chirp up again, so I thank you BigWalleye for your advice.
Adios, and good hunting.