depends on the protections the psu has built in. a quality unit made by a respected brand will simply shut itself down before damaging itself or the pc. a junk unit with little protection built in can blow itself and take some or all of your pc's with it.
"titanium" is not an indication of quality. it is simply a sticker the company slapped on the side of the psu suggesting it is efficient. titanium means that 90+% of the power it pulls from the wall actually gets used by the pc and not wasted. depends on the load to how efficient it really is. but there is no independent testing of this to get the sticker. a company decides what they feel their psu is and slaps that sticker on it. tom's tests many psu's and finds a lot of them do not meet the requirements for the sticker on the side of it.
there is a certification a company can seek to deserve the sticker but they often send n a fake unit with better specs than what they intend to sell to get the certification. nothing stops them from using the sticker even if they do not send one in for certification.
what specific brand and model is this psu? if it's quality, you can try it out but there is no guarantee it will work. it may boot and surf the web but once you start a game or other gpu intensive task, the psu will shut itself down since it can't handle the load.
if you're gonna spend $1500 on 2 gpu's it is worth it to spend a little more on a quality power plant to run them. you would not buy a Ferrari and settle for a 4 cylinder chevy engine in it to save cash. that's just silly and a waste of the car body you bought.