Oh can you get an 8 second CalTrac car down the track sometimes? Sure you can, once in a awhile but it's going to be a crapshoot each and everytime.
Do any amount of racing and you'll see what I mean. Go to a high dollar race at an unfamiliar track where you only get two time runs and see how well that goes. No time for tuning or adjusting, you better be "on" when you get there.