"Torpedo remote detonator" vs "remote torpedo detonator"?
As usual it depends on what you wish to modify. The pointy tip of the torpedo has [most of us assume] a detonator. It is the remoteness that is the most important part of your invention. You are modifying the location of the detonator to your local control. That is a remote detonator. For this reason the "Remote" must be out in front describing the torpedo detonator, or just the detonator. So go with remote torpedo detonator or just remote detonator.
You are worried it might sound like you are detonating your remote torpedo. Don't be. I should hope it would be remote however it gets detonated.