It's just like everything else. How much power do you have? As power goes up everything needs to get better. A high 11 second car will probably hook with just about any shock if it has enough tire. As the power goes up, the tire gets hit quicker. When that hit becomes to quick for your present shock to slow it, it's time to upgrade. So be honest with yourself. If you are going to continue to add power. Buy a better shock to start with.
Doug