I went from a stock flywheel to a 7.5lb fidanza flywheel. The difference is night and day...I love it. Best engine mod I've done to my car besides the nitrous. I don't know my 1/4 mile time before and after, but I'm sure it took off a few tenths. People will tell you that a 7lb flywheel is too light for daily driving, you'll lose torque, blah blah. Those myths are not true, and spoken by people who don't have one. I wouldn't trade mine for the world.