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FPR question

Discussion in 'A4/S4 forum(B5 Chassis)' started by audi-a6, Sep 5, 2013.

  1. audi-a6
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    audi-a6 Member

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    [Sep 5, 2013]
    Looking at upgrading the fuel system on my a6 2.7t, done all the lines, new pump and rs4 injectors on the way, i found a new Fuel Pressure regulator (5 BAR). question is, will it make any difference? will it give me more fuel flow to the engine as a pose to my current 4 bar regulator?
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  3. aragorn
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    aragorn "Stick a V8 in it!" Staff Member Moderator VCDS Map User

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    [Sep 5, 2013]
    its a two edged sword.

    First of all, yes, higher rail pressure will allow the injectors to flow more fuel, BUT, the pressure is offset by boost. That means if you have a 4 bar regulator, and have 1.5 bar of boost, the rail pressure increases to 5.5bar. The problem is that the higher the pressure, the less fuel the pump can flow, and obviously your putting everything else under more stress too.

    5 bar static pressure is quite simply far too high. All you'll end up doing is breaking the fuel pump.
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  4. audi-a6
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    audi-a6 Member

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    [Sep 5, 2013]
    but if i have a pump to cope and a map to suit?
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  5. aragorn
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    aragorn "Stick a V8 in it!" Staff Member Moderator VCDS Map User

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    [Sep 5, 2013]
    buy larger injectors instead.

    There is NO reason to be running a 5 bar regulator.
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  6. audi-a6
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    audi-a6 Member

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    [Sep 5, 2013]
    cool, already got rs4 injectors now lol
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  7. audi-a6
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    audi-a6 Member

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    [Sep 5, 2013]
    sad time, guy that was selling fuel pump has turned out to be an idiot! so i still need a fuel pump, any ideas as to which one..... ill be running 630cc injectors
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  8. jcb
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    jcb Active Member VCDS Map User

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    [Sep 5, 2013]
    Bosch motorsport 044
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  9. audi-a6
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    audi-a6 Member

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    [Sep 5, 2013]
    yeah i looked at them, but arnt they external?
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  10. jcb
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    jcb Active Member VCDS Map User

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    [Sep 6, 2013]
    no.
    Run them in a V8 cage and filter
    minor modding required

    [​IMG]

    [​IMG]
    #9

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