Gravity III upgrade

[Turbinesurgeon]

I wanted to share my experience upgrading my 2006 Sunsport Gravity Games III ballast. I recently purchased this boat as a project and I really have no experience with the way the factory system worked.

The center ballast I left the factory bag 1180 installed and retained the factory drain pump. I used the factory Rule pump to feed just the center tank. I left the scupper intake as is, I didn’t want to cut it apart so instead of using a sprinkler valve to prevent auto fill I installed a 2 wire 3/4” electric ball valve and used the existing wire to the sprinkler valve. Works great!!

In the left and right rear lockers I installed 1100lb fat sacs. The factory Johnson drain pumps didn’t work so I replaced with Piranha 800 pumps. I also installed two new intakes with Piranha 800 pumps dedicated to each ballast tank. I used the existing left and right wires from the sprinkler valves for the fill pumps. I changed out the 3 amp fuses to 10amp. I had to disconnect the center pump wires from the left and right switches so it wouldn’t turn on when I’m trying to fill left or right ballast. I also installed vent lines since they didn’t have that from the factory. Just used a Y and check valve and tapped into the drain line.

I used as much existing 3/4 line as possible. Everything I ordered except the electric ball valve came from WakeMakers for around $290. $45 for the electric ball valve. I originally ordered the Tsunami pumps but they were out of stock so they sent me the Piranhas at no extra charge.

Went to the lake last Tuesday it it works great. I didn’t record any fill times, I can do that tomorrow when we go out.

Great mod if your on a budget.

Couldn’t upload any picture, sorry

[Glenwyatt]

Were you able to use the original manifold with the ball valves?

[Turbinesurgeon]

I junked the manifold set up. I have individual pumps for each bag. The two new fill pumps for the rear bags have mushroom inlets so no need for a sprinkler valve. The center bag is still on the scupper style intake so I installed an electric 2-wire ball valve so it won’t auto fill while driving.

[sandm]

good upgrade. searching through the forums will bring lots of info on swapping out the old sprinkler setup.
never got around to doing it on my boat as I traded but it was on the to-do list.

[denton.leo]

Did you install the ball valve before or after the pump?

[Turbinesurgeon]

Did you install the ball valve before or after the pump?

I have the electric ball valve after the pump where the in-line filter use to be.




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[SpitzerCR]

Do you have photos of where you drilled the holes through the bottom? Im scared to death of drilling into this thing lol

[MJHSupra]

Do you have photos of where you drilled the holes through the bottom? Im scared to death of drilling into this thing lol

If you are drilling two new holes, you want them to be close to you exist one. My 2007 Supra had the original one in the front of the drive, on the drivers side. I put the 2nd hole about 6-8” back towards the transom on the same. Still close to the front of the drive and easy to get to.

I measured the 3rd hole to be on the opposite side, passenger side, in front of the drive. All three were easy to get to once I pulled the back seat off.

Wakemakers has some videos on how to drill and not crack the gel.


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[Turbinesurgeon]

Do you have photos of where you drilled the holes through the bottom? Im scared to death of drilling into this thing lol

I was too but I couldn’t just live with a single pump system. I used the aerator pump set up and what I did was put my brass valve, pick up, and pump together and then searched for good locations to mount them. I have a paddle wheel perfect pass so I stayed away from mounting in front of that. Once I found a suitable location I then mapped it out and insured nothing on the trailer like bunk boards would interfere with the mushroom pick up. Also note the cross beams on the trailer will interfere with drilling your new holes. Once I found the location I drilled a small pilot hole from the inside and then from the outside I drilled the large hole. One pump was mounted on port side abeam where the v-drive transmission meet. The other one was mounted starboard side just in front of the v-drive. Hope this helps you.


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[SpitzerCR]

Is there a recommendation on how to space them so there is no compromising the strength?

anyone have photos they could post or show?

I put in my wake makers order yesterday. The stock rule pump is doing the front and one back and I'm adding a 800 for filling the other surf side bag.