[SIZE=10.5pt]Lots of good people are commenting here, and people that know tunnels extremely well. Here my opinion on weight, and CG. In my opinion focusing on CG can be very dangerous. If you are trying to duplicate CG to someone else, that often can be a very quick way of goofing up your setup. Even if the CG you are duplicating is on the same type of hull. Prop, motor angle, motor height, speed of the boat Act... all work as a relationship to setup and CG. If you set up to someone’s exact CG that works for them, you might find your boat handles poorly. Because you’re not considering the multiple factors that make a tunnel handle. I know on all the tunnels we run, not one of them we know the CG on. In my honest opinion CG isn't really where we focus. Also, as you increase the speed in a tunnel the handling changes quickly. For every 3 to 5 MPH you gain in a tunnel, we've found the set-up needs to change a little with it. If you're running 50, and make a jump to 55 I guarantee you’re going to have to make some adjustments to set up. [/SIZE]
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[SIZE=10.5pt]As far as weight. When adding obviously the lower you can add the weight the better. Posts above had some great ideas for getting weight as low in the boat as possible. Once we get a boat close we might use a little weight if the boat still has some minor handling issues, but only a little. If you ask my Dad, he believes adding weight should be a 2 to 1 ratio. meaning if you add weight 1 once upfront and 2 ounces in the middle of the boat. If your adding a lot of weight to the front of a tunnel, you'll probably notice you create another big problem. The propeller of a boat is naturally pulling the back end of the boat down. So, if you add a lot of weight to the front of the boat when you back off the throttle for the turn the propeller slows and pulls down the back end less. The extra weight in the front then amplifies the nose of the tunnel coming down hard in the turn. As a result, you see tunnels dart hard in the turn, or roll over. So, adding lots of nose weight most likely is going to make your boat turn poorly. Think of a teetertotter. If a heavier person removes themselves quickly from the teetertotter, the lighter person comes crashing to the ground. Props and lots of nose weight are a very similar relationship. Remove the prop pressure, the nose of the boat comes down hard. [/SIZE]
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[SIZE=10.5pt]On all the tunnels, we've ever run for records, none of them had over 5 ounces in the front (just in front of the radio box, no weight ever on the nose or tips of sponsons). In recent record runs we've almost removed all the weight. We've focused on the aerodynamics of the boat, rather than weight. I believe you can get much more weight from airflow, than physical lead weight. Likewise, if you don't have to add much weight, entering turns at higher speeds is a lot easier to control.[/SIZE]
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[SIZE=10.5pt]In my opinion; Propeller, Motor Angle / Height, and Aerodynamics are where I think handling should focus on. Weight and CG are part of the equation, but in my opinion they are much less of what to focus on. The speed of the boat is also a huge factor in the setup relationship. I know I’m repeating but the faster you go, set up will change. Which is why it’s very dangerous to duplicate another boats exact CG. [/SIZE]
[SIZE=10.5pt]Jay Halbrehder[/SIZE]