a55 stock airbox coupled with v-stack
The metal mesh aftermarket ones work well but mine needed replacing and I wanted to try something different, so I did this a couple days ago and am happy with the results. First I found a cheep velocity stack for $15 shipped on ebay here
Was a little too tight and wouldn't go over the lip on the phva, so hand sanded for about 5 mins and slipped right on.
Opened up stock airbox and removed the restrictive foam filter element and long rubber snorkel (if you just cut the snorkel down it causes a bunch of turbulence right at the mouth of the carb intake side.) Widened the hole in the sideways post that goes into the frame, and wrapped the end with some metal mesh to help filter anything out.
Used angle grinder to add a small secondary hole (and riveted a bit of screen over it) because on the first test run it was slightly 4 stroking up top with the same jetting I was using with metal mesh filter (62 main.) Now it's crisp and clean at all throttle positions and throughout rpm range, and it seems to have better pickup.
Since the rubber snorkel is no longer there to hold the airbox to the carb, a couple zip ties helped secure things nice and tight.
You may be wondering why not just run the stack by itself...it took longer than I liked to get up and running well if it was raining or recently had rained, and also needed the choke for longer than it does now when its really cold. Plus it offers no filtration by itself, which I didn't like. Putting the stack in a relatively unristricted, air-stilling, filtered environment has worked out well for me so I wanted to share.