Ian, it is really early in the morning here in Georgia and I can't sleep (got boat race stuff on the brain!) so I will be happy to start with some of my ideas, but probably not pages worth today.
-First, SAW running is a whole different sport than heat racing and you must have a different frame of mind about a lot of things you do.
-Consistency is not much of a factor in SAW. It is not important to have your boat run 6 laps every time you launch it. You want one pass each direction on perfect water as fast as it will go...THATS ALL YOU ARE LOOKING FOR. In fact Ross' .12 boat is WAY too consistent...it runs back and forth the length of the lake with every pass within a couple mph of each other for the full tank of fuel. And it has NEVER blown off or crashed...this is bad because it tells me it is not close enough to the ragged edge of max performance. There is more speed to get out of it. I am happy with a launch, a pass or two the get the motor warm and three solid passes...after that the boat should be getting a little light.
-RPM is speed. Weight is RPM. If a fraction of an ounce lighter will let the motor turn the same prop an extra RPM then it is worth it! SAW boats should be built to be disposable. They don't need to last for years (or maybe even months!) or have fancy paint jobs, they just need to be fast! Yea, you need prop pitch to go fast, but you need to turn it fast enough to be in the motor's powerband.
-Getting the motor's HP to the water is very important. The motor mount system, stuffing box, strut, drive shaft, drive dog, prop and prop nut has to be very solid, vibration free, smooth and streamlined. You don't want to use your HP to turn the cable in a bunch of thick grease or binding stuffing box. You don't want you prop beating the water to death instead of pushing it (I can tell when the prop is working and the boat is going fast because the rooster tail will lay down real flat and be real solid looking)
-Water drag is bad! Don't have anything touching the water that doesn't have to. For a rigger that means the very back edge of the front sponsons (NOT TOO WIDE) and the bottom part of the prop. A turn fin is not necessary on a lot of boats, but if one is needed it should be small. SAW boats don't drive like heat race boats...they kinda coast through most (maybe all) of the turn and then accelerate like a shot out of a gun when you pull the trigger.
Well, without going into great detail (lack of space and sleep) about how I take care of each of the above topics, this is a basic overview of what I consider to be important for SAW.
I will be happy to provide more detail later if requested.
Glenn
