There is nothing wrong with your temperatures, they are completely normal. Not everyone's system is the same and not everyone has great airflow in their case. You can't compare your result to what others are getting.
The key thing is that your fans are staying low. Most people seem to have a poor understanding of how Turbo Boost 2.0 works. If you check a utility like Afterburner, you'll see that there is setting for "Temp Limit". This is the temperature that your card targets for its normal operating temperature. Guess what? For the GTX 770 that temp is right around 80c (you can check yours to confirm). So your card will increase its Turbo Boost clock speed until it reaches that temperature. When it reaches that temperature, it will increase fan speeds and decrease Turbo Boost clocks to make sure it stays there.
So your fans are not overcompensating for a hot card by running really, really fast. You have left out an important factor, which is your Turbo Boost clocks. I'm assuming they are minimal and you are running at regular stock speeds. So in terms of temperature, low to mid 80c's is completely exactly how the engineers designed it. If you want to increase your Turbo Boost clocks, then make sure you have good case ventilation and follow some of the advice others have given. Or you could just leave it alone.