While chatting with Mike Rummage at Tilley's, I asked him about the claimed "up to 10HP gain" on their web page.
I asked for the dyno sheets to back that up. He claimed he would provide them. He emailed me later to say he's "still looking".
:whistling:
I am always leery of claims like this. It can gain you 10hp if the filter you are using now is choking you down the 10hp. If the filter is flowing enough and the heads, eahaust or cam is the restriction. A bigger filter isn't going to do anything. On a stock 110 w/ 255 cams. I can't see a filter gaining 10 on the top. Statements like that need to kept in context.
A buddy machinist of mine was part list building a late model engine. He has it up on the wall. With all the wizbang filters, plugs, wires, headers, spacers, manifold........ He has already gained 200hp with out picking what size engine it is going to be.