Is Clutch Dumping Bad?

Dumping the clutch will shock the driveline and cause the rear to either hop or wheel spin. Once you get more serious into racing, traction bars, better clutch and diffs, more agreessive tires are things that will be needed.

Do you dump the clutch when downshifting?

To downshift, you should be using the clutch and the brake while you shift gears, rather than the clutch and the gas pedal. But always make sure to get back into first gear as you start accelerating again! ... Popping the clutch, or releasing it too quickly, will cause your car to lurch and stall out.

Is it OK to shift without using the clutch?

Shifting your car without using the clutch isn't necessarily bad for it if it's done properly. However, you shouldn't expect smooth shifts like you get when actually using the clutch pedal. Therefore, if you try this in your car, then you might hear some grinding until you do it correctly.