Weight distribution on a Tunnel...(found nothing with search)

[pwerwagn]

Hey Guys, I have been searching for hours and cant find anything about weight placement on tunnels.
I found one thread that regarded batteries for a stereo, and something was mentioned about keeping the weight as far back as possible.

I have a fineline centurion tunnel, with the center sponson. Im currently doing some re-rigging, and was putting all the weight in the back.

I noticed something though. My boat has backwards facing seats behind the driver/pax seat, as well as a rear bench. If I have people ride on the rear bench, it takes forever to plane (I assume due to the mota being lower in the water), and I loose top end speed.

Should I be mounting my battery further foward? FWIW, the fuel tanks are already mounted up by the driver, as far foward as possible (about 2/3rds forward), and they are 11gal each, 1 on each side in the side sponsons.

Thanks for your help.

--Jeff

[Hot Shot Merc]

Yes I would mount batteries and pumps as far forward of the rear erea as posssible.Not in the front of the boat though.

[pwerwagn]

Cool, thanks. I will try mounting the batt somewhere around the drivers seat, if that sounds good. probably foward of the bulkhead somewhere, still in the rear 2/3'rds of the boat.

Also, I dont know if it means anything or not, but it requires a lot of positive trim to reach max speed. I have the motor just over 1" lower than the lowest part of the stepped hull in the center.

I appreciate the help!!

--Jeff

[Hot Shot Merc]

Raise the motor to flush with bottom and watch water pressure.I wouldnt go that far forward with the battery.Keep it behind the driver but forward of the bilge area if you know what I meen.

[pwerwagn]

Thanks for the help Rob. I currently have it 1" below because I only see 10psi at WOT. Im planning on a LWP this winter though to solve that. Id like to at least see 80mph eventually.

Thanks again.

--Jeff

[SFRacing]

careful mounting it too far forward, the boat will be a lot bumpier up there, and your boat will handle differently when you get a low water pickup. If you are going to the lwp, i would leave the battery in the back, set the lower where hotshot suggested, buy a cleaver (or other stern lifting prop) and start working your engine height up from there untill it is running how it should

most likely it is not so much the weight location, your boat does not handle well because you are running a tunnel with a sub-surface lower unit.

[beer30]

What do you have for set-back and what props are you running? Chuck

[pwerwagn]

It doesnt handle bad at all, it handles like a dream actually. Im just lookin for more speed!!!

I currently have a 21p laser II, for skiing. It will run dead nuts 60mph with that prop.
I also have a 24p chopper, small ear I believe. It will turn the chopper just over 6Krpm with a little pos trim, rooster tail about 3' higher than the cowl. Ir runs around 67 with that prop.
Also have a 26 chopper, but it doesnt even pretend to turn that!!!!

As far as setback, I have a 6" walker man jack plate. Im not really sure what total setback is, also not sure if setback should be measured from rear most part of transom, or the further forward stepped portion.

FWIW, the 1" below that im speaking of is the lowest part of the hull, not the rear most part of the transom.

--Jeff