ORIGINAL: aerobob

Personally, and NO offense meant to anyone (and yes, I've shared this view with Scott).....

Angled intake tubes, called "stacks" are not induction rams. They have no venturi. They either create turbulence at the butterfly, or PREVENT turbulence at the butterfly. They either increase power, or they do NOTHING. They keep the plane cleaner, or they make it more difficult to choke. Or maybe easier to choke.

Point is - post a poll in the Gas Engines forum about the benefits, and I'd bet a broke prop that the results will only tell you about people's "beliefs" on these things. They aren't a gimmick; I'm not saying that.

ZDZ designs and sells true "intake Trumpets", that are installed on their REAR intake motors (means carburetor intake is inside the fuse) and those things DO make a difference. They also are a true venturi shape that has been engineered.

A piece of round tubing of some length (BTW - all "stacks" seem to be the same length, regardless of the motor they are installed on. Would make one wonder about "tuning", no??) stuck on the end of a carb just gets in the way in most motors. Vast majority of guys aren't gonna carve up a cowling to have a piece of tubing stick out. I won't, anyway.

Like I said - this feature is a "belief system".... for some it is "gotta have", for others, a "who cares"..... if it makes a difference on your motor, and you like it, then it "works", and is "needed". If not, well, you're in the same place as about 95% of the other gas engine owners....