Well in theory, the lump does help create and direct the air over the short side radius. But long before the lump was ever developed or conceived, racers were still setting records and winning without it, and they have also set records after the lumps were considered the standard without using them also. Tom also dyno tested that comparison and I think he reposted the results in another post recently regarding another question. But again, the divided port concept is relatively untested on so many levels and could open up a whole new generation of mods that puts the lumps on the shelf like an 8 track tape. There is already plenty of evidence showing and proving it works both with and without lumps.
