Upgrading from gravity 1 to 3

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Originally Posted by jester

Ok so i am looking to upgrade from Gravity 1 to a gravity 3 and wanted to know if anyone had any ideas. Below is a layout of what i will do with a pic.

I will replace the current pump with a Jabsco pump that will fill and empity.

Add 3 more valves. One for each side and an extra one for adding another sac for surfing.

Wire the whole system up. Yet to be figured out but it is just wires and who cares if one bag fills when one is drainned.

I do not know if i would need to overfill holes / air holes. Would make it easy to see when the bags are full by the water flowing out the side of the boat.

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Jester,
Get rid of the sprinkler valves. Two ways to upgrade. You can use 3 pumps to fill and three pumps to drain. Or you can use the Jabsco reversable pumps. They have their own valves in them so water will not drain out. If you go with the fist way that I mentioned, there is a few more steps than just adding more pumps and getting rid of the sprinkler valves. I have pictures of my install in my profile if you like to take a peak.
Tazz

Tazz, I think Jester already did this upgrade. It was a march 09 post that pmoomba ask a question to bring it forward.

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Originally Posted by pmoomba

I got a used 06 OBV with the G1 system and will eventually be looking for a ballast upgrade. My main priority would just be some rear bags that I can fill/drain with a switch along with the center bag. It doesn't have to be the biggest/fastest system around, just looking for the switch convenience mostly.

I'm not opposed to trying to build it myself but I'm pretty wet behind the ears and would probably need a lot of help. A few basics (some of these maybe be totally incorrect questions so just help me out, also boat is away in storage so I can't go out to look)-

I read through this article but it seems mostly centered on upgrading the stock system for decreased fill times. I'd currently be ok with the stock system, just looking to increase to 3 bags.

Given a 2006 OBV with the G1 from the Dealer -

- Apart from needing a lot of details, are there any big gotchas that I'm not aware of that would prevent an "easy" upgrade G1 1 bag system to a 3 bag system? Something in the basic design in my boat that would make this just fundamentally not work without a lot of knowledge/experience/labor.

- Is this something I can expect to do with existing intake, pump, etc? I'm not really sure I'm up to making new intakes. I know that a redesign with multiple intakes/pumps would be faster but I'm starting small.

- In the picture above the pump goes through the cutoff valve into a piece with 3 solenoid valves connecting. What is that piece? (or is it just a logical block). Should I expect whatever is in my boat to be easy enough to hook up the other two solenoid valves or is that something that would need replacing?

- I'm pretty sure I only have one exit/drain hole on the starboard side. I'm assuming it'd be in my best interests to make a new on on the port side. What's involved in making one?

- Is this something the average dealer might be able to do as well, and if so what's a rough upgrade estimate?

- JesseC's diagram above doesn't make this look unattainable by my low experience level but I don't have the experience to know what simple (or not so simple) things I might be be overlooking or might get me into trouble.

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pmoomba,

See the pic below of the GIII system manifold in my boat. These are just lawn sprinkler valves and plastic pipe and fittings you can buy at home depot. Your current single fill pump will feed into this this manifold. You will need to buy one aerator evac pump for each sac you add. You will also need to drill two holes above water line for the evac line (just buy the correct size hole saw, tape the gel coat with masking tape, then drill the hole in reverse), one for each sac, just like the one you have now for the one sac (so each sac will have it's own evac pump, hose, and thru hull fitting above water line. You will also have to buy two more switches. You can get the fat sacs and fittings at places like buywake.com, wakeside.com, etc. I had mine converted by the dealer from GI to GIII before I took delivery. They charged me the factory upgrade price of $795.

Hope that helps.

Al

http://i250.photobucket.com/albums/g...7/IMG_0980.jpg

AL, I can't believe you don't have a water strainer, or where did you hide it?

Mine didn't come with one and I guess I didn't really think I needed it. But from what I have read lately, I've decided to add one. It's on my list for this winter.

Anyone ever have this done at a dealer or another shop? I got my boat used so don't have a specific dealer, but called the only one that's near me and got a quote (on the order of $1k per side) that adds up to more than the full GIII option when purchasing a new boat. Based on what he was saying it sounded like the price came from SC. It would be 2 new intakes and 2 new pumps (among the rest of the work/equipment). I guess in some ways I can see how it could be more to make the changes to a completed boat vs. during the production process when it's more open, but that was still more than I would have expected.

I haven't written off doing it myself but am keeping options open. That would be an upgrade over what my plans would be (adding 2 bags to existing 1 intake/pump system), so there are some benefits (as well as some assurance of a good job vs. my inexperience), but I don't want to get taken either so was looking for some basis for comparison.

Quote:

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Originally Posted by pmoomba

Anyone ever have this done at a dealer or another shop? I got my boat used so don't have a specific dealer, but called the only one that's near me and got a quote (on the order of $1k per side) that adds up to more than the full GIII option when purchasing a new boat. Based on what he was saying it sounded like the price came from SC. It would be 2 new intakes and 2 new pumps (among the rest of the work/equipment). I guess in some ways I can see how it could be more to make the changes to a completed boat vs. during the production process when it's more open, but that was still more than I would have expected.

I haven't written off doing it myself but am keeping options open. That would be an upgrade over what my plans would be (adding 2 bags to existing 1 intake/pump system), so there are some benefits (as well as some assurance of a good job vs. my inexperience), but I don't want to get taken either so was looking for some basis for comparison.

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pmoomba,

As I mentioned in an earlier post, I paid $795 to go from GI to GIII. I had negotiated this into the sale price so I think he worked with me on the price. This is the same upgrade price had I ordered it new.

You have an '06 so I assume it uses the old style system, i.e., separate pumps for intake and evac. The GIII upgrade would include a manifold, two solenoid valves, two sacs, and two evac pumps (one for each added sac).

If you were told that they would be adding two intakes and two pumps, that leads me to believe that they are upgrading you using the new system - one reversible Jabsco pump and one intake per bag. Those pumps run around $200 each I think. You should call them back and tell them what system you currently have and what upgrade they plan to do. I guess it would be okay to mix and match the old and the new system.

Either way, you will save a lot of $$ doing it yourself if you are so inclined.

Al

jmvotto, I Have not done the upgrade yet at i did not want to break down the system in the Summer. Now for X-mas my family has gotten me two fat sacks so some time in the next two months i will be working on this project. I do not know if i will go with three Jabsco pumps or install two drain pumps and drill thru the haul.

Either way you go the system will function just fine, but if you use Jabscos (or Johnson Ultra Ballasts) you'll have a system that fills quite a bit faster as each bag will have it's own dedicated fill pump instead of sharing the common factory fill pump.

If you want to do it as inexpensively as possible add additional sprinkler valves and individual drain pumps. If you want to increase the speed of the system at the same time, go with the impeller pumps.