I'll assume this is the type of clutch you have in your EVO. I don't think HPI has really deviated from this style in the RS4 line. The clutch is a very important part of the engine and it can make or break a perfect setup. This link should explain in detail.
You didn't mention if this was a brand new car. If it is your shoes will have all three holes still in tact.
When your engine is broken in and adjusted properly so it idles nicely and doesn't bog when you accelerate you can start to tune the clutch to your driving style. You can't adjust externally so you'll have to pull the motor to make the changes. Note, once you cut the shoes you can't go back. Just buy some spares, I don't recall them being expensive. Also get a spring or two, they do stretch over time and can be damaged easily from constant removal and installing. They can stretch out too much.
FYI, when I had my HPI Type SS many moons ago I was using the third set of holes (so I cut off the other two). I found this gave the motor a nice launch off the line and didn't bog the engine before it took off. Of course I tried it stock first, then the second holes which was a bit better but I wanted more grab. The third holes gave me the sweet spot for the stock engine the kit came with.
See what works for you and your driving style.
Ok, going to bed now, racing tomorrow!