Center of gravity?
#41
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From: Milton, Fla!
Wow!
And that was a 43?
And that was a 43?
#42
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From: St. Pete Beach, FL
#43
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Great Thread. With all the talk of a Further-aft CG being best, what is the reasoning for staggered setups? My best friend owns a 39 Outerlimits quattro, staggered 525s and XRs on ITS transoms. Boat runs in the 90s and handles very well. Would it run faster rigged side by side but handle worse? Im sure each setup has its ideal CG location and what works on a straight bottom v may not work with 4 steps and a notch. Honestly curious. I'm putting together a 272 Formula, 468 BBC and bravos, and contemplated moving the batteries and trim pumps up under the rear seat to move the CG forward any little bit as it handles ass-heavy at anything below 55-60mph. Wants lots of tab not to porpus.
#44
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From: SW Ohio
Great Thread. With all the talk of a Further-aft CG being best, what is the reasoning for staggered setups? My best friend owns a 39 Outerlimits quattro, staggered 525s and XRs on ITS transoms. Boat runs in the 90s and handles very well. Would it run faster rigged side by side but handle worse? Im sure each setup has its ideal CG location and what works on a straight bottom v may not work with 4 steps and a notch. Honestly curious. I'm putting together a 272 Formula, 468 BBC and bravos, and contemplated moving the batteries and trim pumps up under the rear seat to move the CG forward any little bit as it handles ass-heavy at anything below 55-60mph. Wants lots of tab not to porpus.
It has always been my understanding that the purpose of a staggered setup had everything to do with the relative depth of the drives while planing vs on plane. With side-by-side, the props are set really deep at idle and planing, so that they can be at the proper depth while on plane, forcing a reduction in prop pitch to get on plane. The prop depth doesn't change nearly as much with staggered twins, which allows for more pitch in the props. I would guess staggered handles better at speed, but is less agile while docking.
Thanks. Brad.
(937)545-8991
#45
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From: Milton, Fla!
Staggered installs also let’s them mount the drives closer together which keeps the props in the water longer, as the hull lifts.
(As stated above)
On my OB’s they are mounted on a 24” center to center (the min for twin OMC loopers) for this same reason.
You can get your hand between the cowlings but not your arm.
(As stated above)
On my OB’s they are mounted on a 24” center to center (the min for twin OMC loopers) for this same reason.
You can get your hand between the cowlings but not your arm.
Last edited by Twin O/B Sonic; 09-19-2022 at 07:45 AM.
#46
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From: Lake Ozark, MO USA
I noticed on the BT when it was docked at Captain Ron's, that there looks to be some sort of extension on the back of the hull from the outer chines inward and back. Would like to see that boat on a trailer to look at the bottom. Those things rode and handled the Lake right out of the box.
#47
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From: Lake Ozark, MO USA
#48
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Dvr4hire,
It has always been my understanding that the purpose of a staggered setup had everything to do with the relative depth of the drives while planing vs on plane. With side-by-side, the props are set really deep at idle and planing, so that they can be at the proper depth while on plane, forcing a reduction in prop pitch to get on plane. The prop depth doesn't change nearly as much with staggered twins, which allows for more pitch in the props. I would guess staggered handles better at speed, but is less agile while docking.
Thanks. Brad.
(937)545-8991
It has always been my understanding that the purpose of a staggered setup had everything to do with the relative depth of the drives while planing vs on plane. With side-by-side, the props are set really deep at idle and planing, so that they can be at the proper depth while on plane, forcing a reduction in prop pitch to get on plane. The prop depth doesn't change nearly as much with staggered twins, which allows for more pitch in the props. I would guess staggered handles better at speed, but is less agile while docking.
Thanks. Brad.
(937)545-8991
#50
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From: Taunton Ma
Thanks for the info, I honestly didn't know the full reasoning for staggered twins. Part of me thought mainly CG related, getting CG forward and the center of the mass of the driveline /motors closer to the center of the boat. I never considered that moving the drives towards the centerline on a v-bottom boat effectively raises the X dimension while at speed, due to how the water comes off the hull.


