Questions: fuel tank/pump for LS conversion

Discussion in 'High Tech Retrofits' started by daniel76309, Jan 28, 2009.

  1. daniel76309

    daniel76309 Veteran Member Lifetime Gold Member

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    I am researching options for fuel pump/tank for my upcoming LS3 conversion, and have done some searches. There seems to be a bit of conflicting info regarding the return fuel line...

    1. If I run an in-tank pump, is a return line necessary (or desireable)?

    2. I was thinking of copying this technique:

    http://www.cardomain.com/ride/2532279/2

    using a new Goodmark tank, but then I ran across this:

    http://www.paddockparts.com/Paddock...Fuel&mscssid=AE743029284849C3B5E79B5349C89C9A

    which seems like a pretty good deal, about $600 complete, which isn't all that much more than it would be for a new tank, pump, etc. The only thing that concerns me is that they don't seem to mention any baffling inside the tank. Anyone have any experience with these tanks?
     
  2. 77LT1

    77LT1 Veteran Member Lifetime Gold Member

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    You will need to run a return line even though the pump is mounted in the tank. You don't want a deadhead style regulator for fuel injection.
    As far as tanks go, I like the idea of the first one. Without pics of the second one, it's hard to tell exactly what you're getting. I went the easy route and just sumped the stock tank in the rear. If I were to do it over again, I would do something similar to the first one. It wouldn't be all that hard to baffle the tank once you cut the hole.

    B
     
  3. John Wright

    John Wright Veteran Member Lifetime Gold Member

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    I like the tanks inc pump...it adjusts to the depth of the tank and comes with it's own baffle.
     
  4. BondoSpecial

    BondoSpecial Veteran Member Lifetime Gold Member

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    Is the tanks in pump the one with the tiny little sheet metal tray around it? If so I looked at that too, I wouldn't exactly call that a baffle. Has anyone used the PA-4 and can comment on whether it is baffled enough for aggressive driving with a lower tank of fuel? If I were to cut open a new tank anyway I would weld some much more substancial baffling into the bottom of the tank itself
     
  5. ErikNORCAL

    ErikNORCAL Veteran Member

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    from the part numbers in paddocks I believe those are the one's manufactured by spectra and carried by one or several of the sponsors here. I know people are using those tanks but its escaping me who right now - just ask in the high tech area for feedback.
     
  6. daniel76309

    daniel76309 Veteran Member Lifetime Gold Member

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    "Tanks" for the info...

    I kind of figured I would need a return line, but I have seen some pumps that are "regulated" at 58 psi, for example--which led me to believe that they would not need an external regulator and return line.

    This is the Tanks, inc. module with tray:
    http://www.tanksinc.com/index.cfm/p...category_id=61/home_id=61/mode=prod/prd84.htm

    I agree with 77 TPI though...If I am going to cut up the tank anyway, it wouldn't be that hard to add more baffling. I would think that a "tray" surrounding the fuel pickup, an inch or so tall, with the walls slanting about 45 degrees inward, so that fuel can slosh in easier than it can slosh out, would work. Any better ideas on that?
     
  7. John Wright

    John Wright Veteran Member Lifetime Gold Member

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    1/8" or 3/16" holes drilled at opposite corners of the baffle/tray to allow fuel in and not run back out quite as easily.
     
  8. BondoSpecial

    BondoSpecial Veteran Member Lifetime Gold Member

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    58 psi is too high for most EFI. ALso you want rising rate pressure in many applications, not totally fixed
     
  9. daniel76309

    daniel76309 Veteran Member Lifetime Gold Member

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    Thanks, the holes sound like a better idea.

    I am no expert at this, but I was thinking that the rating, e.g. 58 psi, is at full voltage, and that the ECM varies voltage to the pump as is needed by the engine, so that there would be less fuel pressure at idle and part throttle, and full pressure at full throttle/high rpm. Is that not true?
     
  10. ErikNORCAL

    ErikNORCAL Veteran Member

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    I thought 58psi was pretty standard for LSx engines? Some people bump fuel pressure to get higher ratings out of their injectors ie: 30lb up to something like 36lb injector
     

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