Announcement

Collapse
No announcement yet.

Boost guage

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Boost guage

    Ok so after a wee schoolboy error I now have a working boost guage
    Question is what should it be reading.....2.5 tdi 888 special intercooler ready but not yet fitted
    Sitting 70 - 80 mph gauge is reading 6 is this ok or does turbo actuator need tickling

  • #2
    6 what? PSI?

    And how accurate are guages... I bought a cheap sundely one from fleabay - I can get a boost spike of nearly 25psi (on my guage...), but hold it for too long and it goes into limp mode.

    Sent from my Moto G (4) using Just T4s
    Last edited by Adventure Van; 17 July 2018, 08:54 PM.
    '00 1.9TDI LWB, '87 Mk2 Golf 16v

    Wheel or tyre question? Just ask, it's what i do!

    Comment


    • #3
      Yes mate PSI
      What I'm trying to see if that reading is average for the 2.5 tdi

      Comment


      • #4
        6psi (0.413685bar) is low. Cannot recall exact numbers but circa 11.6psi (0.8bar) is the mapped max with a top limit of 14.21psi (0.98bar) before it overboosts and goes into limp mode. Will check exact spec next time I fire up the PC.

        Sent from my SM-G901F using Just T4s

        Comment


        • #5
          Seems low but could just be your gauge. My 88hp 2.5TDI will sit at 0.6 bar at high revs and will peak to 0.8 briefly when at lower revs (2,500 rpm)

          Also I don't think you can actually "tickle the actuator" on the 2.5's as it's electronically controlled. You'd need a bleed off valve to cheat the ECU into giving more boost... but it might not be too happy and trigger limp mode.
          1999 2.5 TDI

          Comment


          • #6
            Originally posted by Davieb View Post
            Ok so after a wee schoolboy error I now have a working boost guage
            Question is what should it be reading.....2.5 tdi 888 special intercooler ready but not yet fitted
            Sitting 70 - 80 mph gauge is reading 6 is this ok or does turbo actuator need tickling
            Depends what load and what the throttle is doing, mine can show a few psi at 70 or 20+ psi if I'm hard accelerating.

            Comment


            • #7
              Mine reads a max of 14psi. 2.5 AJT with intercooler. And it's red!

              Comment


              • #8
                If you adjust the actuator preload you will be messing up the pre-determined map, the knock on effect is over boosting = limp mode against the specified boost table. The tolerance is only 300 mbar. Accelerate hard (foot to floor) in 3rd and observe the max psi then try different throttle positions to get the boost range.

                Sent from my SM-G901F using Just T4s

                Comment


                • #9
                  Off up to Glasgow in the morning so I will give it a bash
                  Cheers

                  Comment


                  • #10
                    Originally posted by Activ8 View Post
                    If you adjust the actuator preload you will be messing up the pre-determined map, the knock on effect is over boosting = limp mode against the specified boost table. The tolerance is only 300 mbar. Accelerate hard (foot to floor) in 3rd and observe the max psi then try different throttle positions to get the boost range.

                    Sent from my SM-G901F using Just T4s
                    Wont the N75 run a higher duty cycle to get the boost back down into range?

                    I need to log mine as I think it's running out of available duty cycle


                    But yeah - do a carpet mashing run in third, see what max your boost gauge records - that'll give an indication. May well be the turbo rather than the gauge at fault? Could you tee into a tyre(foot/hand) pump on a tyre and see what the boost gauge records in comparison to the pump gauge?

                    Comment


                    • #11
                      Originally posted by regcheeseman View Post
                      Wont the N75 run a higher duty cycle to get the boost back down into range?

                      I need to log mine as I think it's running out of available duty cycle


                      But yeah - do a carpet mashing run in third, see what max your boost gauge records - that'll give an indication. May well be the turbo rather than the gauge at fault? Could you tee into a tyre(foot/hand) pump on a tyre and see what the boost gauge records in comparison to the pump gauge?
                      Yes it is but changing the pre-load alters the opening and closing position %'s in the N75 map shortening the available duty cycle range.

                      Sent from my SM-G901F using Just T4s

                      Comment

                      Working...
                      X