View Full Version : Stacking bags work?

05-26-2008, 11:59 PM
About 2 weeks ago I posted in the "your set-up's" about stacking bags and plumbing them into the Grav-3 system. I have recieved a couple messages regarding the success of the set-up. So.. here you go.
To answer the question.. Yes it works but with many side effects. I plumbed it up putting a T in the empty hose so when the lower bag was full the water flowed straight through the t and into the other bag. Then when both were full the water would run out through the tee and out the existing discharge. Two major problems..
1 You have to make sure both bags have NO air in them or the empty pump will cavitate and the top bag will not empty. You have to burp each bag as they fill, = pain in the butt. You will have to do it every time you fill them because air always vents through the port.
2 both bags stacked are higher than the overflow on the outside of your boat. So as the top bag fills the path of least resistance is through the overflow out the side of the boat. I fixed this by installing spring checks with about 1psi of backpressure to stop the problem. With 1 psi you get about 27" of water column so the water wants to fill the bag because it sees over 2' of head pressure out the discharge. I was worried the pumps would not lift the springs but they worked great. This allowed me to have a fair amount of pressure in the bags = More weight. 1-2 psi will never rupture your bags but it will let you ad a few more pounds to the system.
Like I said if there was no cavitation problem I would leave it, and I am going to deal with it in the bow. The LSV loves that 1000lbs in the bow. I've opted to go with the 750's in the rear. I'm going to contact Pro x and see if they will build me bags that use the existing space from the factory 450's plus the headspace filling the rest of the locker. That would be like 1200lbs in each locker! That will probably be more than I want to spend, but we will see.
Original set-up I spoke of worked really well as far as wake shape. We did add a 450 on the seat behind the driver later and made a v-e-r-y surfable wave. About 4 1/2 tall and I could surf about 20' back on a 4'6" board. I'm 6' and 205lbs.
Sorry I had Pics but my camera got wet and well you get the idea. Will post when I get more.
Hope this helps, any feedback would be great.

05-30-2008, 06:26 PM
Let us Know what they come back at you with a price I am intrested in filling the compartment my self. Just depends on the $

05-30-2008, 07:56 PM
I talked to a dealer and was told the enzo sack fits well with a little room to spare in the LSV. 1148lbs would do just fine on each side. ;)
Waiting on a price. Will update you when I know.