Building a C Mod motor

[dpracer95]

I've gotten the chance to be good friends with a couple of the guys down there. As some have come back year after year to race at Top O with us. Joaquin Moran (reigning 2 time champion) has been running the expansion chamber the last 2 years and has been the fastest. Other than running an expansion chamber what else could I take down there to win this race? They do not have ANY I repeat ANY rules or regulations when it comes to modifying. Anything goes!!

[johnsonm50]

Raging speed, power & control are one thing [or 3] but a rig that will go the distance counts for alot.

[johnsonm50]

I wanted to write about boats and heights of the motor too. Hydroplanes used in the C Mod class or 500 mod class range between 10'6" and 11'6" long and width of 36" to 37". The boat weight should allow you to be within 25lbs of the minimum weight allowed. My son is 155lbs, so he can use a heavier boat. The amount of lift built in the boat should be around 2" to 2 1/4" on a 37" bottom boat. Lift can be measured by using a straight 12' two-four on the bottom. The amount of distance at the front is the lift when the 2x4 is held on the bottom. If your heavier than the average driver, 210+ then you may build more lift in the bottom.
How high can you go with the motor? In the last 15 years, in stock racing, APBA have put limits on motor heights. In Mod racing there are no limits to how high you can raise the motor. With the introduction of the four blade propeller, you can raise the motor higher and still go straight. Deeper traps have also help keep the boat to go straight. As you raise the motor, you have less sgag or lower unit in the water. As the boat gets more air born, the boat will break loose and want to move the back of the boat to the left or right. It's possible for the boat to turn so severe that you loose control and the boat will turn over. This will happen while you are going in a straight line and is very dangers if you are in close competition. If you experience this, lower the motor till you have complete control.

Agreed: " If you experience this, lower the motor till you have complete control. " Having the rear kick to port is not an 'if' but when you will be barrel rolled.