jaredb900rr

From what I've read, people that dropped the tank to install the GDP or AirDog draw straw have had problems because the draw straw measurement length sitting on the floor is not the exact same measurement as when it is sitting in the straps on the truck, especially if you're using a jack to hold up the tank. This is causing the majority of the problems with peoples' 1/4 tank issues and I'm sure this is what PureFlow is talking about when they talk about installation "error".

I installed a GDP unit and did the same as tritont, where the draw straw reached the bottom and actually bent a little cuz I left it a tad long, and then I cut a slight angle to it so it could rest on the bottom of the tank but still suck fuel. Obviously, when you run your truck below 1/8th tank there is going to be sloshing occurring which equates to a slight fluctuation in fuel pressure. But, mine would never go to 0 psi, and I could run it below the red and beyond 0 miles til empty on the overhead display as long as I was driving on flat roads.

Since most people don't drive on perfectly flat roads everywhere they go, a few members here tried plumbing the pickup and the return into the canister to help suck up every last bit of fuel in the tank and to make sure that when they were below 1/4 tank (which is about where the canister cup height is) that they weren't sucking the cup dry. I don't have experience with the Airdog100 and Raptor100 pumps, but I would bet they're pretty close to not sucking the cup dry below 1/4 tank. But, when you step up to the 150 series pumps, the cup is definitely getting sucked to empty. Mark and a few others have tried drilling a few small holes at the bottom of the canister to allow fuel from outside the canister to get sucked up from the pickup inside, in hopes that with the return filling the cup as well as outside fuel coming in, that the cup won't get sucked dry. I have one of Mark's modded Liberty canisters with my 150 and it works for my measly 700hp.

It seems like these experiments are working in the right direction, but as people push the power envelope, like onetun, even more fuel flow is needed. It's great that PureFlow is stepping up and listening to the needs of their customers. I'm looking forward to seeing the new pumps!

Sorry for the long rant!

WICKEDDIESELS

The biggest problem with a big "GPH" fuel system is that alot of fuel is cycled. Fuel can be drawn out of the module far faster than it will re-enter. Fuel needs to be returned back into the module, not into the filler neck. A necessary modification is to drill several small holes into the bottom of the fuel module, this can also cause fuel to escape the module as the fuel begins to slosh at low tank levels.

It would be nice to have a larger, volume canister to store more fuel to be picked up, that could still allow fuel to easily enter it.

A company use to make a dual pickup, that went inside the tank. The setup used 2 pickups that were attached with hoses to a central port. Each pickup had a ball that rolled fore and aft, to open or seal off that particular pickup. The ***** would roll back and forth inside the pickup assembly from acceleration and decel. That way wherever the fuel was in the tank, it was drawing the fuel, and the other ends port was covered by the ball to eliminate air being sucked in. I may check into this and see if it is still available.

2007 5.9

If there was a way to slow down the "Fuel Return" the emptying of the module would stop.

Those of you who happen to have no 1/4 tank issues, are lucky. There are more than a few of us who have them. For the most part, it is not a reflection of a "Poor Install". I had mine done at a reputable shop in my area who has discussed at length with Toby the Air Dog Tech support guy, and they have brainstormed for several hours on how to fix this...but nothing so far excpet for return to the canister.

Fisherguy

Both myself and 2007 5.9 tried the Liberty module and the AD100, and if you read our posts we we can both tell you the AD100 will easily suck the canister dry.

Wicked, a bigger canister is not going to help, it will only mean it takes longer to suck it dry, the engine return cannot keep up to the AD, plus a bigger canister would not fit into the tank unless the opening was enlarged.

Either way, I think we're getting Onetun's thread sidetracked...

Hvytrkmech

I have had absolutely zero 1/4 tank issues. I have run it down till the fuel light comes on. 18psi at idle then 16psi at wot with the Quad on it, and that's run through the factory filter housing then through my GDP 2 micron set up.



Tim

chrleb1

LOL... we went from having a lot of power that would suck down a 150 to people having 1/4 tank issues.

Hvytrkmech

Yeah we did didn't we. sorry

What do you run for peak manifold pressure?



tim

2007 5.9

Sorry for that Onetun. Gonna have to start my own thread and stop riding on yours!!!

OPIE

One of my customers runs the Liberty module and feeds my Gusher pump setup with it. I don't know what hp you are at but he has never reported any such problem and he is very competitive and runs it in 10.99 index races.

2007 5.9

Does your "Gusher" pump have a regulated return or non regulated??? In other words can one control the amount of fuel that goes back in the filler neck or where ever it goes???

O.T

No issues guys, these forums and threads are for everyone to get heard.

I ended up adding a Wabro, so in theory I have between 230-240gph free flow. Engine likes this and have been able to maintain a good 15psi to the pumps.
Tomorrow I dyno so we will se what other gremlins I might have///

Rob

jwb600

didnt you dual walbro pumps before? I ran just one and it did fine for a long time. but im not in the 1khp range either

jwb600

not to get off topic but my truck will go from around 30 psi to zero and back and forth. I went over everything a couple times after we did the install. it runs fine out on the street and im not trying to take away from your thread just stating what mine does. im not unhappy with the airdog I think its a pretty good product and I have called and talked to them before just havent had time lately to get the issues fixed.

chrleb1

78 lbs of boost. The big turbo is loafing at 25-26 psi.

chrleb1

Let me know how it goes.