CO2DELIRIOUS

For some reason my fps keeps dropping when online, my pc can handle the graphics and my internet connection is good but i start losing fps when coming across certain players driving in front of me, whether they be a few meters away or even kilometers away.... just facing the direction of their current location makes my game lag XD, how ever when i go in the opposite direction or "looking back" in game the game seems to run normal, could somebody please help me since i just started playing online and really love playing this game with my Logitech Driving Force Ex:sulk::panic2: