External pump + oem, return considerations.
Thread Starter
Burning Brakes
Joined: Oct 2010
Posts: 763
Likes: 2
External pump + oem, return considerations.
I am thinking now of just using the OEM pump with regulator blockoffs and an external. But with this setup the return will be in the tank rather then the OEM sump.
I don't imagine that them stock pump would outflow the speed of the gravity feed + siphons, but it concerns me a little to not give it consideration.
Those using this setup, is your return plumbed into the sump, or not at you have no issues?
For those unsure what I am referring to, normally the "return" goes right back into the oem sump that is in the gas tank, so the only gas actually "lost" from the sump is that consumed by the engine. The sump has a small (1/4-1/2") flapper gravity feed on the bottom, once the gas is lower than the top of the sump, that is that is the only way the sump is filled (besides the passenger and under sump siphon). With the return no longer plumbed into the sump, the pump is actually pumping full flow out of the sump, without the excess being returned to the sump and could theoretically flow faster than that flapper and the siphon.
I don't imagine that them stock pump would outflow the speed of the gravity feed + siphons, but it concerns me a little to not give it consideration.
Those using this setup, is your return plumbed into the sump, or not at you have no issues?
For those unsure what I am referring to, normally the "return" goes right back into the oem sump that is in the gas tank, so the only gas actually "lost" from the sump is that consumed by the engine. The sump has a small (1/4-1/2") flapper gravity feed on the bottom, once the gas is lower than the top of the sump, that is that is the only way the sump is filled (besides the passenger and under sump siphon). With the return no longer plumbed into the sump, the pump is actually pumping full flow out of the sump, without the excess being returned to the sump and could theoretically flow faster than that flapper and the siphon.
Safety Car
Joined: Dec 2009
Posts: 4,754
Likes: 303
I am thinking now of just using the OEM pump with regulator blockoffs and an external. But with this setup the return will be in the tank rather then the OEM sump.
I don't imagine that them stock pump would outflow the speed of the gravity feed + siphons, but it concerns me a little to not give it consideration.
Those using this setup, is your return plumbed into the sump, or not at you have no issues?
For those unsure what I am referring to, normally the "return" goes right back into the oem sump that is in the gas tank, so the only gas actually "lost" from the sump is that consumed by the engine. The sump has a small (1/4-1/2") flapper gravity feed on the bottom, once the gas is lower than the top of the sump, that is that is the only way the sump is filled (besides the passenger and under sump siphon). With the return no longer plumbed into the sump, the pump is actually pumping full flow out of the sump, without the excess being returned to the sump and could theoretically flow faster than that flapper and the siphon.
I don't imagine that them stock pump would outflow the speed of the gravity feed + siphons, but it concerns me a little to not give it consideration.
Those using this setup, is your return plumbed into the sump, or not at you have no issues?
For those unsure what I am referring to, normally the "return" goes right back into the oem sump that is in the gas tank, so the only gas actually "lost" from the sump is that consumed by the engine. The sump has a small (1/4-1/2") flapper gravity feed on the bottom, once the gas is lower than the top of the sump, that is that is the only way the sump is filled (besides the passenger and under sump siphon). With the return no longer plumbed into the sump, the pump is actually pumping full flow out of the sump, without the excess being returned to the sump and could theoretically flow faster than that flapper and the siphon.
Thread Starter
Burning Brakes
Joined: Oct 2010
Posts: 763
Likes: 2
Funny, I was looking at your thread and was thinking of PMing you. Rubber submersible hose is surprisingly expensive, but for the price you can actually just use a quality stainless/PTFE hose.
