dearl
Well-known member
I posted this on Mean Chicken, thought I'd post it here too with the number of guys running Jets now.
I have a 2010 Lowe Roughneck 1655D tunnel hull powered by a 2008 Mercury 90/65 jet outboard. I recently went through and replaced the floors and decks in .080 aluminum, and used 1.5 x1.5x.125 tubing for braces. Before the mods it had .125 decks and floors which made the boat pretty heavy. Then it would run 32-34 mph with an occasional 36 if the water was flat, and you couldn't make it porpoise. Now with only 2 batteries at the stern, forward console, 19 gallon fuel cell under the front deck, running empty I can only get 33 tops. To say the boat is light is an understatement, The boat drafts very shallow now, which was what I was after, but the lose in speed has me puzzled. New liner, good grating, smooth bottom. Motor runs like a scalded cat.
Before the mods, I could adjust the trim and get In the sweet spot, she would dig with no over spray. Now with minimal trim adjustment I get a lot of spray, then comes the porpoising. It will run with the motor tucked in the tunnel, but at 31 mph. It almost feels like the hull is stuck to the water, I know that some tunnels create low pressure areas causing a vacuum so to speak, and I'm wondering with the new weight distribution, if this is what's happening. I have already planned to move both batteries under the front deck to distribute more weight, the nose of this boat is very light even with the fuel cell under the front deck.
When I come off of WOT It almost feels like the hull stays "stuck" to the water for a bit and then breaks free and slides fairly easy. From looking at my tunnel and reading some topics here on tunnel dimensions, I'm wondering if some tunnel work would benefit this hull. I have since removed the strake you see inside the tunnel, but haven't had it back In the water yet. I don't have the tunnel dimensions with me but will measure them when I get home and post them later. Here are some shots of the hull when I had it flipped to do some bottom painting, and another of the hull when we took it out after the re-wire and before the rear deck. The boat rides great, has awesome throttle response, goes super shallow, but its not as fast as it was when it was heavier than now, Any thoughts or input is appreciated.
I have a 2010 Lowe Roughneck 1655D tunnel hull powered by a 2008 Mercury 90/65 jet outboard. I recently went through and replaced the floors and decks in .080 aluminum, and used 1.5 x1.5x.125 tubing for braces. Before the mods it had .125 decks and floors which made the boat pretty heavy. Then it would run 32-34 mph with an occasional 36 if the water was flat, and you couldn't make it porpoise. Now with only 2 batteries at the stern, forward console, 19 gallon fuel cell under the front deck, running empty I can only get 33 tops. To say the boat is light is an understatement, The boat drafts very shallow now, which was what I was after, but the lose in speed has me puzzled. New liner, good grating, smooth bottom. Motor runs like a scalded cat.
Before the mods, I could adjust the trim and get In the sweet spot, she would dig with no over spray. Now with minimal trim adjustment I get a lot of spray, then comes the porpoising. It will run with the motor tucked in the tunnel, but at 31 mph. It almost feels like the hull is stuck to the water, I know that some tunnels create low pressure areas causing a vacuum so to speak, and I'm wondering with the new weight distribution, if this is what's happening. I have already planned to move both batteries under the front deck to distribute more weight, the nose of this boat is very light even with the fuel cell under the front deck.
When I come off of WOT It almost feels like the hull stays "stuck" to the water for a bit and then breaks free and slides fairly easy. From looking at my tunnel and reading some topics here on tunnel dimensions, I'm wondering if some tunnel work would benefit this hull. I have since removed the strake you see inside the tunnel, but haven't had it back In the water yet. I don't have the tunnel dimensions with me but will measure them when I get home and post them later. Here are some shots of the hull when I had it flipped to do some bottom painting, and another of the hull when we took it out after the re-wire and before the rear deck. The boat rides great, has awesome throttle response, goes super shallow, but its not as fast as it was when it was heavier than now, Any thoughts or input is appreciated.