Nothing, besides maybe a trigger for preference. The trigger takes a little getting used to, but in the end, you can run on it.
-Trigger frame is a little complicated to remove.
When i got my Evil Pimp, brand new in the box, i took it out in front of my good buddy, Andrew Gore (former Evil tech). Without even touching air or paint, he went right to the settings and put it at what he knows is best. BIP(Ball in Place) = .6-.8 ROF(Rate of Fire) = 25 ETS(Elec. Trigger Sens.) = 0 Dwell =7-8ms (or possibly lower).....12-16 flashes from all the way down.
After changing the settings, i slapped on my Reloader B, which was nice and snug
o-ringed feedneck. Then I inserted my crossfire LP, (yes, it runs on HP, AS WELL AS LP), and got ready for some action.
Right to the chrono I went. The marker comes ready to rip when you get it, but if you want consistency, effecincy, and maximum bps, you're going to need to tinker a bit. The Evil detonator reg, is a little confusing at first, but the manual is very helpful and will show you what to do. Since i was running an LP tank, i needed to adjust my pressure settings on the HPR, and LPR. (High Pressure, and Low Pressure Regulators) When i got the gun to its optimal air settings,(100-150psi on the LPR, and went from the bottom up on the HPR since there is no HPR guage.)
Now i was ready to sling paint. And that I did. For sure, after the many guns I've been through, and the many guns I've tested....this is one of the most beautiful, and wonderfly constructed guns. With the eyes on you will most likely never chop, with the right pressure settings, and BIP(Ball In Place) settings.
I must warn you though, do not shoot the gun with eyes off. Like any gun without eyes...not very reliable. I chopped paint when i got in the upper BPS with eyes off, so don't do it, unless you like spending time cleaning your gun. BTW, fun, and EASY, gun to take apart down to what you need to clean and lube. So always use the eyes, cause they are really really great eyes, and will not fail you with the right settings.
I CANNOT express how much you will love this gun if you buy or trade for one. The Evil Pimp Kit is goin soooooo cheap on Ebay, and in PBnation. I advise that you at least give this gun a try sometime, somewhere, because i know for a fact that you'll love it and you'll want one right away. Seriously, anyone who doesn't give this gun at least a 9, is bullsh|++ing you, and they need to get their gun tuned/ teched. BUY IT!!!