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Dual pumps of different size question.

 
Old 05-14-2019, 10:00 AM
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Default Dual pumps of different size question.

Hopefully not too dumb of a question...Can I run a 450 and a 255 pump? It will be plumbed with -8AN to a regulator before the rails. Planning on using the stock feed line as the return. Sound OK?
Thanks,
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Old 05-15-2019, 05:05 PM
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Nobody??
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Old 05-15-2019, 05:52 PM
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How about calling WS6store, a vendor/sponsor here. They will give you a straight answer as to what would work or not. They are very honest and will treat you right.
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Old Yesterday, 05:54 AM
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You can run whatever you want.
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Old Yesterday, 09:34 AM
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Originally Posted by stevieturbo View Post
You can run whatever you want.
Obviously. However, I think the OP wants to know what would be the most sensible thing to do under his circumstances.
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Old Yesterday, 09:45 AM
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Originally Posted by G Atsma View Post
Obviously. However, I think the OP wants to know what would be the most sensible thing to do under his circumstances.
And he really hasnt given a lot of detail of those circumstances.

But there is no reason why he could not use those pumps, or equally dozens of other configurations. Why choose such a large disparity between pump sizes ?....who knows though.
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Old Yesterday, 09:50 AM
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Originally Posted by stevieturbo View Post
And he really hasnt given a lot of detail of those circumstances.

But there is no reason why he could not use those pumps, or equally dozens of other configurations. Why choose such a large disparity between pump sizes ?....who knows though.
I agree with you. But why use 2 pumps, when there are large enough pumps to let one get the job done, regardless of fuel demand?
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Old Yesterday, 09:59 AM
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Originally Posted by G Atsma View Post
I agree with you. But why use 2 pumps, when there are large enough pumps to let one get the job done, regardless of fuel demand?

Because a lot of the very large pumps are either very expensive, or ***** and never perform as well as their claims.

How many very large single in-tank pumps do you know of that you'd trust ?
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Old Yesterday, 10:11 AM
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Originally Posted by stevieturbo View Post
Because a lot of the very large pumps are either very expensive, or ***** and never perform as well as their claims.

How many very large single in-tank pumps do you know of that you'd trust ?
Good point....
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Old Yesterday, 05:13 PM
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Ok, to clarify. I currently have a 255 in the car and a 450 on the bench. I need to upgrade for the 393" to be run on E85. I mean I could just buy another 450 but, as many of you know I'm "frugal", and then what to do with a perfectly good 255. Thanks for the input.
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Old Yesterday, 05:27 PM
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Same with any pump setup. As long as it's all configured right, suitable wiring/connectors etc...then it can work just fine.
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Old Yesterday, 06:04 PM
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Originally Posted by G Atsma View Post
I agree with you. But why use 2 pumps, when there are large enough pumps to let one get the job done, regardless of fuel demand?
Another reason people choose to use two small pumps over one large pump is heat. You can run a small pump when demand is low and have the other turn on only when needed and it doesn't heat up the fuel as much.
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Old Yesterday, 07:53 PM
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Yank the 255, install the 450. Problem solved.
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Old Today, 03:25 AM
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Originally Posted by LLLosingit View Post
Another reason people choose to use two small pumps over one large pump is heat. You can run a small pump when demand is low and have the other turn on only when needed and it doesn't heat up the fuel as much.
Yet almost all of the people complaining about heat...have never logged fuel pressure, so really have no clue what temperatures they are seeing...hot or cold. Which seems a little baffling as the pumps themselves impart very little heat to the fuel.
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Old Today, 06:36 AM
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"It will be plumbed with -8AN to a regulator before the rails. "
Backwards....To the rail[s] first. Then to the regulator.
The 450 may overrun the stock feed line.
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Old Today, 06:39 AM
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Originally Posted by Old Geezer View Post
"It will be plumbed with -8AN to a regulator before the rails. "
Backwards....To the rail[s] first. Then to the regulator.
The 450 may overrun the stock feed line.
Either or, it doesnt really matter. FPR can be run in either position, although most do prefer after the rails.
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Old Today, 08:37 AM
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Originally Posted by Old Geezer View Post
"It will be plumbed with -8AN to a regulator before the rails. "
Backwards....To the rail[s] first. Then to the regulator.
The 450 may overrun the stock feed line.
I understand, I think I misspoke.
The -8an line will feed the rails from the tank. Why would the stock feed line (3/8") not be sufficient for return?
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Old Today, 08:45 AM
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If someone want to draw me a diagram that would be awesome. I also need to pull fuel off the rail for the nitrous solenoid.
Thanks,
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Old Today, 09:31 AM
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The stock fuel line can be a return as it will not flow as much fuel as the supply line. The engine uses some of it.....
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