What it is: Supra/Moomba BagBuster Ballast Upgrade (2002-2008)

This kit is designed for 2002-2008 Supra and Moomba wakeboard boats equipped with the Gravity III wakeboard ballast system from the factory. When a bag is selected and added to the kit, quick connects will already be cemented in just like the factory bags. Because any upgraded bag will be taller than the factory bag, we include a prefabricated fill hose extension that will quick connect to the factory hose. The extension is made with the same hose and fittings as the factory connection to simplify the install. The entire installation is completely plug-and-play, takes less than two minutes, and requires no modifications to your boat.

For Use In:

For specific questions on fitment, and for possible compatibility with other models, click here.

Dimensions:

• 400lbs – 42″ x 16″ x 16″
• 565lbs – 42″ x 19″ x 19″
• 750lbs – 50″ x 20″ x 20″
• 1,100lbs – 50″ x 24″ x 24″
• 1,450lbs – 108″ x 25″ x 25″

Starting at $19.95 Buy Now »

Dan loaded up his 2008 Moomba Outback V for wakesurfing using the Moomba Gravity III factory ballast system and two additional Launch Pad ballast bags. The result as you can see from the video above is a very surfable wave. To get the most out of your Moomba Outback V Gravity 3 Ballast System replace your 400lb. rear ballast bag with the Wakemakers Moomba BagBuster Ballast Upgrade (2002-2008) or the Moomba BagBuster Rear Ballast Upgrade (2009-2011) depending on the year of your boat. Both ballast kits include the fittings and any necessary hose extensions you will need to replace the factory rear ballast bag with a larger Fly High Fat Sac.

Factory Ballast System Specs:
Bow Ballast: N/A
Center Ballast: 400 lbs.
Rear Port Ballast (Left): 400 lbs.
Rear Starboard Ballast (Right): 400 lbs.

Wakesurf Ballast Configuration:
Bow Ballast: N/A
Center Ballast: Fly High Moomba Ski Locker Sac 400 lbs.
Rear Port Ballast (Left): Straight Line Sumo V Sac 750 lbs.
Rear Starboard Ballast (Right): Empty
Extra Ballast: Launch Pad Sumo Jr. V Sac 400 lbs. (Placed on the Port side seat)

Wake Plate or Wedge Settings: Wake Plate 1/4 Up
Speed: 10.5 mph
Occupants: 2
Prop: OJ 14×14.25

What’s Wrong?
There are three main issues with the factory Gravity III system Supra and Moomba installed from 2002-2008 (the ballast system was essentially identical throughout this entire process, with the exception of bag sizes, which vary by model and the day of manufacture):

1) Slow Fill Times: This is a result of the fact that the factory system uses a single Rule aerator type pump to fill from one to three bags depending on how many switches you turn on at one. Additionally, the system uses solenoid valves designed for use in a below ground irrigation system to control the flow of water to each of the three bags. That means when you turn on the fill switch for a particular bag the system is engaging the fill pump AND opening the solenoid valve to that bag. The more bags you try to fill, the more the longer it’s going to take as the output of the single fill pump is routed to all three bags by the solenoid valves.

Additionally, the sprinkler valves are designed to maintain pressure (which is important for an irrigation system with retractable heads), but decreases volume significantly (which is what we’re interested in for a ballast system). Removing the sprinkler valves would increase the speed of the system by close to 50%, but would sacrifice the ability to control which bag is filling because any time the fill pump is on it would be sending water to all three bags.

2) Inconsistent Draining:  The factory system has an individual Rule drain pump for each bag.  Because aerator pumps are not self-priming it is crucial that the drain pump be mounted in close proximity to the bag it is draining (we prefer to have the pump mounted directly to the bag).  The Gravity III system has the pumps for the rear bags mounted approximately two feet away, which was down to preserve the appearance of the installation.  While it certainly is nice

3) No Vent Connection:  In the factory configuration there are only two connections to each ballast bag; one for filling and one for draining.  While the drain connection can act as an overflow to prevent damage to the bag or boat if the fill pump is left on too long (a common occurrence due to the slow speed of the system), because it is connected to the bottom of the bag it does not allow air in the system to be vented.  That means the bag can have a significant amount of air trapped inside of it, which will limit the capacity of the bag.  This is especially a problem for the center bag, but can occur with all three.

What’s The Fix?
Although the specifics can vary depending on goals, budget and time, there are basically two methods of upgrading the factory system to correct the issues outlined above:

Option 1: Upgrade to reversible flexible vane impeller pumps (Jabsco Ballast Puppy or Johnson Ultra Ballast) which is the route Moomba and Supra have chosen for 2009 and newer boats.  The advantage to this layout is a drastically simplified system with far fewer components, less hose, and a dedicated vent on the top of the factory bag.  Additionally, with one pump connected directly to each bag in the system, fill and drain times are reduced significantly.  The disadvantages to this layout are that it requires the installation of two new thru-hull connections for the additional pumps, and flexible vane impeller pumps are significantly more expensive, so the complete system ends up costing around $900.

Option 2: Install additional aerator type pumps (like Attwood’s Tsunami 800) along with additional hardware resulting in an individual fill pump for each of the bags in the system.  This setup also provides an individual fill and drain pump for all three bags, and does not require the sprinkler valve distribution manifold that is present in the factory system which further increases speed.

This configuration does not allow for a dedicated vent connection off the top of the bag, which is the only real disadvantage.  It’s also significantly cheaper to install this system than the flexible vane impeller based option above, but there is more install work to be done.  The parts for this upgrade total around $300 without the vent connections, or $400 with the hardware to connect a vent line to each bag (which requires bags with three ports on them).

You can view one of our customer’s installation summary on the Supra Boat owners website here.

Other Options
If you are content with the speed of the system and just want to enlarge the capacity of the bags for surfing or wakeboarding we do offer a factory upgrade kit for 2002-2008 Moomba and Supra wakeboard boats which includes everything necessary to replace the rear ballast bag with a larger capacity model (up to 1,450 pounds).

If you have any specific questions about upgrading the ballast system in your Supra or Moomba, feel free to contact us via email at sales@wakemakers.com or by phone at (888) 338-6085.

Whether you’re designing a new ballast system, or trying to upgrade your existing system to fill and drain faster, one common question is how best to design the system so it is as uncomplicated (and also inexpensive) as possible.  One of the tools that we use when helping people design a custom ballast system is a product called a vented loop.

As shown above, a vented loop is a “U” shaped plastic fitting that is installed in series with the fill pump when using aerator pumps.  During filling, the vented loop is invisible, functioning as a section of hose without any limitations.  The beauty of the vented loop only comes into play when the the fill pump is turned off, which means there are no drawbacks to implementing its use.  When water is not being forced through the fill hose, air (but not water) is allowed to pass through a vent at the top of the loop, which allows the column of water from the vented loop to the fill pump to drain down to the level of the pump.  

It is this column of air (typically at least two feet long) that prevents water from siphoning into, or out of the ballast bag when the pump is not running.  Many people are under the impression that water is forced past the fill pump due to the boat running at speed, but it’s not possible to develop that much pressure, and it actually just the siphoning process that allows the bag to fill or drain.  The vented loop solves that problem by creating a break in the column of water running from the pump to the bag, so siphoning is not possible.

To function correctly, the vented loop needs to be installed close to the ballast bag in question, and as high above the water line as possible.  For forward ballast bags, the typical installation location is under the driver’s dash up near the windshield.  In the back of the boat, up under the gunnel, whether in direct drive or v-drive boats, is typically the best location.

If you have any other questions about the vented loop in particular, or ballast systems in general, please feel free to contact us.

Moomba uses one Rule 2000GPH pump to fill all of the bags in the boat. If you only have the center ballast option, then it will fill it fairly quickly, but if you’re complaining about the fill speed, you probably have at least GIII system on your boat (or even larger upgraded bags). If that’s the case the fill capacity will be approximately 660GPH to each bag. In an ideal world, that would result in around 5 minute fill times for the standard 400 pound bags, but ballast systems have lots of less than ideal characteristics. In the factory system, the biggest roadblock is the sprinkler valve manifold system that Moomba uses. Even when open, they have less than half the flow volume of the 3/4″ hose that is used in the boat. Cutting the volume of water in half results in fill times of around 10 minutes, nearly twice the ideal rate.

So what does that mean in terms of actually upgrading the speed of the system? The Rule fill pump used in the system is the largest capacity pump you can really get for this application, so there isn’t a quick fix there. Basically, there are two main options for decreasing the fill time:

1. Replace the stock single fill pump and valve manifold system with three individual fill pumps, one for each bag. In addition to increasing the theoretical fill capacity from 2000GPH to 2400GPH (or higher), the big speed up will be removing the restrictive sprinkler valves.
2. Replace the three restrictive sprinkler valves with quarter-turn solenoid valves. These work the same way, but don’t limit flow at all when open. They are expensive though, at around $60 each.

We typically recommend option 1 because it will cost less, be more efficient, and will be more reliable because three pumps are doing the work of one pump. Unfortunately though, neither one will be a simple install, it will require some reworking of the factory components.

If you have additional questions about upgrading the factory ballast system in your Moomba boat, feel free to contact us and we’ll be happy to help outline your options.