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Twin O/B Sonic 09-18-2022 01:37 PM

Wow!

And that was a 43?


Originally Posted by hogie roll (Post 4845261)


hogie roll 09-18-2022 05:52 PM


Originally Posted by Twin O/B Sonic (Post 4845332)
Wow!

And that was a 43?

Yes it’s a 43.

Supposedly the hull heritage is a popped 9’ wide midnight express hull with 2 steps and pad added at some point. The parveys have worked on their bottom as well. The 43s seems a bit rare compared to the 46s.

dvr4hire 09-18-2022 08:58 PM

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.

Brad Christy 09-19-2022 06:47 AM


Originally Posted by dvr4hire (Post 4845363)
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.

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

Twin O/B Sonic 09-19-2022 07:41 AM

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.

Helmwurst 09-19-2022 08:03 AM


Originally Posted by hogie roll (Post 4845349)
Yes it’s a 43.

Supposedly the hull heritage is a popped 9’ wide midnight express hull with 2 steps and pad added at some point. The parveys have worked on their bottom as well. The 43s seems a bit rare compared to the 46s.

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.

Helmwurst 09-19-2022 08:04 AM


Originally Posted by hogie roll (Post 4845349)
Yes it’s a 43.

Supposedly the hull heritage is a popped 9’ wide midnight express hull with 2 steps and pad added at some point. The parveys have worked on their bottom as well. The 43s seems a bit rare compared to the 46s.

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.

dvr4hire 09-19-2022 06:34 PM


Originally Posted by Brad Christy (Post 4845404)
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

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.

dvr4hire 09-19-2022 06:35 PM

For my experiences in the bilge, the best reason for staggered setup is the relative ease of serviceability!!

Unlimited jd 09-19-2022 08:01 PM


Originally Posted by dvr4hire (Post 4845497)
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.

brings the rotational mass closer to the centerline of the boat and lower, the propulsion closer to the center, and as you know my drive prop shaft is 1.5” above the bottom. (1” with the spacers installed) If we did nothing but move the drives out 4” on the same horizontal plane, they would be at least 1” below the bottom in that relative line.


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