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COG ????? gen3 cat

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Old 01-26-2012, 06:30 AM
  #1
mopartybob
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Default COG ????? gen3 cat

Howdy all,I'm soon building my first cat,insane gen 3,my ? is that it calls for the fuel cell to be located in front of engine,but would'nt it cause COG issues with a full load=(run wet) vs 1/4 full= too flighty??? I've considered installing the engine 1" further forward than factory specs and installing the fuel bag under the engine,and using the strut to compensate for overall ride attitude...I've seen several cats at my pond with hard tanks and IV bags mounted forward of engine, but the issue is as mentioned above ...runs wet till 1/2 tank,then a little too flighty at top speed as the level drops to below 1/4 , theres only that small window of optimum stability thru-out the full load of fuel.....it's hard to believe that several oz. of fuel can make this difference, but i've seen it..I can understand this point bein mute on a 50ish mph boat ,but what about a 60+ mph boat,.. any idea's 'bout this... thanks MPB
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Old 01-26-2012, 09:03 AM
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expresscraft
 
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Default RE: COG ????? gen3 cat

make sure the boat is at the recommended cg. then instal your tank there on the cg.remember with todays power house motors whats on paper my not work on your boat, we have almost 4 lbs in the nose of our 50" thunderbolt, and the high horsepower k-600 engine does not even know its there, 83.6 mph two weeks ago so the mph is also fine.moving the tank from the center to the sponsons did help in handling. more from a lower cg then where the cg was.
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Old 01-26-2012, 09:34 AM
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mopartybob
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Default RE: COG ????? gen3 cat

Thanks for your reply,my moving the engine forward 1" was to compensate for the weight of the fuel being relocated and to keep strut adj./placement as per specs,as you say,whats on paper might not work for your application,and my guess is that all R&D testing on this gen3 was done with the fuel cell in front of the engine, i chose the gen 3 cuz it does not use the drop-down motor mounts and this would allow relocating the fuel cell under the engine for improved COG and fuel utilization, I myself would not try saddle bagging the sponsons as water/racing conditions are a changing event,but this is my first cat build so the only stoopid ?? are the ones that are not asked... lol I'll bounce this off to their site (jeff) and see what he thinks... Thanks again, MPB
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Old 01-28-2012, 12:32 AM
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Default RE: COG ????? gen3 cat

for those interested,jeff understood what I was intending to accomplish, maintaining a consistent COG thruout the whole tank of fuel,and suggested moving the engine forward no more than 1/4, any further would compromise the stability of the design built into this hull, I'll post the build and test results soon... Thanks MPB
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