2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

dual fuel pumps

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Old Apr 25, 2002 | 06:37 PM
  #1  
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From: kamloops
dual fuel pumps

hey has any body ever heard of having 2 fuel pumps and what are the benafits?
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Old Apr 25, 2002 | 07:13 PM
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From: n
Depends on how you run it...
In series you get more pressure - in parallel you get more volume...

Downside?&nbsp You just up'd the failure factor by two...



-Ted
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Old Apr 25, 2002 | 11:50 PM
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Originally posted by RETed
Depends on how you run it...
In series you get more pressure - in parallel you get more volume...

Downside?&nbsp You just up'd the failure factor by two...



-Ted
But, if one fails, you can probably still get home. If you have one pump, and it dies, youre screwed if youre not at home when it fails.

Ted, kinda OT, but what is the flow rate of the stock pump? I remember hearing it before, but I want to be sure. Wasnt lt like 170 l/hr or something?
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Old Apr 26, 2002 | 01:06 AM
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From: n
Originally posted by mazdaspeed7
But, if one fails, you can probably still get home. If you have one pump, and it dies, youre screwed if youre not at home when it fails.
Not if one of the pump fails and blocks further fuel flow...

Ted, kinda OT, but what is the flow rate of the stock pump? I remember hearing it before, but I want to be sure. Wasnt lt like 170 l/hr or something?
Stock FC turbo is about 180-185lph.


-Ted
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Old Nov 1, 2002 | 11:02 AM
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This is an old question but...

If i run a second TII pump in parallel (tee the 2 outlets together in the tank) then shouldnt i get higher pressure as well as volume.

If volume increases and the fuel lines stay the same then the pressure increases too right?

WIth 2 parallel stock t2 pumps, i should be able to run better then with a sinlge walbro 255 lph right?

Also can i just tee into the line in the fuel tank? And make a holder to bolt the 2nd pump to the first one, run 2 wires and thats it?
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Old Nov 1, 2002 | 01:11 PM
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seems like that would work.. why not use an external fuel pump along with the in tank one.. just buy a Walbro
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Old Nov 1, 2002 | 01:35 PM
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Originally posted by mazdaspeed7


But, if one fails, you can probably still get home. If you have one pump, and it dies, youre screwed if youre not at home when it fails.
but if one fails while you are driving you wouldn't notice. then you floor it, hit boost, and run lean and boom... that happened to SCC mag once on the dyno with a 400hp project mr2. 2nd pump wasn't on. by by engine.

however then they rebuilt it (other one was stock) and made over 500 LOL
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Old Nov 1, 2002 | 02:14 PM
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what about building a colector tank where one flows fuel into the tank and then one flows it out? it realy doens't help with presure but 2 walburo 355's is all you'll need for about 500 hpr, and it would keep your car from running lean...
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Old Nov 1, 2002 | 02:31 PM
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From: Nanaimo, B.C, Canada
hmm i know C-West's race car has 3 pumps.. 2 Bosch ones and a O.E from a R33 SKyline.. to insure a constant supply fuel in pumped from from the main tank to a corrector tank at a high pressure and then fed to the engine to minimine the chance to fuel starvation.. i wonder what they use as a second tank?
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Old Nov 1, 2002 | 02:59 PM
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From: Portage, MI
I assumed that parallel meant seperate lines, like a fuel rail for each pump.

Teeing the lines, wouldn't that just cause a lot of unnesessary flow? The pulsations, and the pumps pushing on each other. I dunno, sounds cheesy to me.

Originally posted by Jahoo88
This is an old question but...

If i run a second TII pump in parallel (tee the 2 outlets together in the tank) then shouldnt i get higher pressure as well as volume.

If volume increases and the fuel lines stay the same then the pressure increases too right?

WIth 2 parallel stock t2 pumps, i should be able to run better then with a sinlge walbro 255 lph right?

Also can i just tee into the line in the fuel tank? And make a holder to bolt the 2nd pump to the first one, run 2 wires and thats it?
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Old Nov 1, 2002 | 03:02 PM
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From: Nanaimo, B.C, Canada
basically pump into one smaller tank and then to the engine.. that works good... two pumps running seprate.. both intank with there own line to the smaller tank
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Old Nov 1, 2002 | 03:53 PM
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I used to run one stock pump intank. that went to a swirl pot,( second tank youare talking about) then a Morroso pump accually feeds the engine.
In this setup, the first pump is there to simply fill the swirl pot. the swirl pot is a aluminum cylinder (or simmilar) with and input at top and the output on the bottom. All this is for is to prevent lean out due to fuel slosh. the swirl pot isn't big enough to slosh much.
It works great. I never had leanout on launch ever again. after I killed that car I put it on my 2nd generation celica. never leaned out in the turns.
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Old Nov 1, 2002 | 04:27 PM
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From: Mars
Sounds pretty pimp. How much did that setup cost you tweaked?
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