Does anyone know by chance how high you can get your strength without power armor?

Using power armor automatically gives you str 10 regardless of your base str. So the max str is the same for both.

20?

OK...My STR is 15 right now and was wondering if I could push it further

I have gone to 22 charisma testing when I was told special has a soft gap of 20 so I can confirm the special cap is not 20.

As for max strength are you counting temporary buffs from items like alcohol and buffout/buffout variants?

20 was just i guess. I don't know which drugs and beer stack but I think getting like bufftats+x cell +clothes+11 str+beer gets 18 or so. There doesn't seem to be any cap for stat boost. I think charisma can be boosted over 30.

edit. I forgot there was also the serum which gives like 5 str so getting over 30 might be possible.

I talking permanent... ( including armor and stuff like that)
Not buffs from aid

..and you can get +6 strengths from alcohol alone when picking correct booze with partygirl/boy perk..

What serum??

"Mysterious Serum"

You get some of them from a questline and even more with certain ending to that questline.

http://fallout.wikia.com/wiki/Mysterious_serum

for further information.

I like the sound of this. I wonder how many "fortified" legendary armor pieces their is....I have 3 right now but havnt found anymore for my other slots.....

Since the Legendary armor can have any effect on any armor piece, there should be possibility to get full suit of it

So it will be possible to get my strength to 29 if other chems don't stack with the serum......