how do u know if you've put too much oil in ur turboed car? would there be puffs of smoke coming out of the exhaust from time to time after letting off the throttle??

I added about a quart of oil in the engine when i was at the track because the dipstick barely had any oil on it when i checked it.. just about a week later i checked the oil level and it was pretty low again.. so i added about .5 quarts to bring the level up a bit.. i do have a minor leak on the oil return line because it is kinda oil soaked and the pan surface seems to be grimed with oil and dirt sticking to it.. gonna get that fixed this weekend though.. and completely redoing the return lines..

any suggestions??