Page 1 of 2 12 LastLast
Results 1 to 10 of 15

Thread: no overboost on let

  
  1. #1
    Status
    Offline
    coupeturborsa's Avatar
    AOC Regular
    Join Date
    Jul 2008
    Location
    South Africa
    Posts
    132
    Mentioned in
    0 Post(s)
    Quoted
    0 Post(s)

    no overboost on let

    hey guys. so i managed to sort out my issues over the weekend, exhaust leak and vacuum leak. car on idle is at -8 to -1 bar vacuum. my actuator is turned up alot but i do not get any overboost.

    with the old turbo, i use to get abt 1.8 bar overboost and settle at around 1.4 bar. now it only goes to abt 1.4 and settles 1.1 to 1.0 bar.

    new vxr turbo was installed 2 weeks ago, with a new boost sensor and internal dv. what could be the problem ?

    do you think that i should get the car flashed to stock and reload the map again ? or is maybe the boost sensor or the actuator ?

    i will post a pic later showing how much the actuator is turned up.
    2002 ASTRA COUPE TURBO - PH3.5
    352 bhp and 370ft lb


  2. #2
    Status
    Offline
    Enkidu's Avatar
    AOC Obsessed
    Join Date
    Feb 2006
    Posts
    2,716
    Mentioned in
    0 Post(s)
    Quoted
    0 Post(s)
    Hi mate

    Please don't wind the actuator up its the quick way to kill the turbo. When you wind it up too much you keep the waste gate from opening fully and keep the heat in the turbo. To adjust properly hold the waste gate shut and wind the nut up to it, then turn a full turn to tighten it, Done! thats all you need to do the ECU controls the rest.

    If your not getting overboost, there could still be a leak or the ECU is not letting it overboost. Try disconnecting the batt for 10 mins to reset it or carry on looking for leaks.
    Arden Astra GSI - Phase 3.5

    EDS Phase 3.5 288 BHP 340 FT/LB

    Inlet cam and Dbilas manifold.

  3. #3
    Status
    Offline
    coupeturborsa's Avatar
    AOC Regular
    Join Date
    Jul 2008
    Location
    South Africa
    Posts
    132
    Mentioned in
    0 Post(s)
    Quoted
    0 Post(s)
    the ECU is not letting it overboost.
    thanks mate.

    with the old turbo on, the car use to overboost with the same map. how could changing the turbo only affect the ECU ?

    I think i will remove the actuator tonight and refit and adjust.
    if actuator is stuffed then I am in a mess as we do no get the courtenay stuff in South Africa.

    I have my actuator on car for about 3 years now, do you think that its time for a change ??
    2002 ASTRA COUPE TURBO - PH3.5
    352 bhp and 370ft lb


  4. #4
    Status
    Offline
    Enkidu's Avatar
    AOC Obsessed
    Join Date
    Feb 2006
    Posts
    2,716
    Mentioned in
    0 Post(s)
    Quoted
    0 Post(s)
    Not sure, all I know is mine sometimes does not overboost especially in the summer. I thought this was for protection if intake is too hot etc.

    But your right it could be a weak actuator (did you not get a new one with the new turbo?) Or a boost leak???
    Arden Astra GSI - Phase 3.5

    EDS Phase 3.5 288 BHP 340 FT/LB

    Inlet cam and Dbilas manifold.

  5. #5
    Status
    Offline
    coupeturborsa's Avatar
    AOC Regular
    Join Date
    Jul 2008
    Location
    South Africa
    Posts
    132
    Mentioned in
    0 Post(s)
    Quoted
    0 Post(s)
    it did come with a new standard actuator but i fitted my old upgraded actuator as it holds boost better. i checked all the lines for a boost leak and there is nothing. put all new vacuum lines in also, changed main boost line from turbo to cooler, put new clamps on, my power pipe is ally and all clamped in well, baileys DV is also on and works fine. you can hear it nicely so no leak there.

    now only need to check the internal dv and the actuator.
    what are the other places that it could be leaking from ?
    2002 ASTRA COUPE TURBO - PH3.5
    352 bhp and 370ft lb


  6. #6
    Status
    Offline
    coupeturborsa's Avatar
    AOC Regular
    Join Date
    Jul 2008
    Location
    South Africa
    Posts
    132
    Mentioned in
    0 Post(s)
    Quoted
    0 Post(s)
    also how much boost can the standard actuator handle ? wanna try one out. i am running up to 1.8 bar overboost, (26psi). will it hold the boost.
    2002 ASTRA COUPE TURBO - PH3.5
    352 bhp and 370ft lb


  7. #7
    Status
    Offline
    davemark's Avatar
    AOC Fanatic
    Join Date
    Oct 2003
    Posts
    962
    Mentioned in
    0 Post(s)
    Quoted
    0 Post(s)
    bit of a cheaky question got any old LET turbos hanging about

    Dave
    DaveMark

  8. #8
    Status
    Offline
    coupeturborsa's Avatar
    AOC Regular
    Join Date
    Jul 2008
    Location
    South Africa
    Posts
    132
    Mentioned in
    0 Post(s)
    Quoted
    0 Post(s)
    i dont wanna be wasting my time putting a standard actuator on if it cant hold the desired boost.

    i will test my courtenay acuator tonight with the air pump to check for leaks.
    2002 ASTRA COUPE TURBO - PH3.5
    352 bhp and 370ft lb


  9. #9
    Status
    Offline
    stinger's Avatar
    AOC Newbie
    Join Date
    Apr 2006
    Posts
    34
    Mentioned in
    0 Post(s)
    Quoted
    0 Post(s)
    From what regal told me the standard VXR actuator holds its own when running maps with higher boost

  10. #10
    Status
    Offline
    coupeturborsa's Avatar
    AOC Regular
    Join Date
    Jul 2008
    Location
    South Africa
    Posts
    132
    Mentioned in
    0 Post(s)
    Quoted
    0 Post(s)
    From what regal told me the standard VXR actuator holds its own when running maps with higher boost
    cool, well i will try one out, i got nothing to loose.
    2002 ASTRA COUPE TURBO - PH3.5
    352 bhp and 370ft lb


Page 1 of 2 12 LastLast

Similar Threads

  1. how much overboost
    By jackdaxter in forum Turbo Petrol Engines inc. Transmissions
    Replies: 17
    Last Post: 10-10-2010, 18:59
  2. No Overboost
    By DarrenG in forum Turbo Petrol Engines inc. Transmissions
    Replies: 2
    Last Post: 19-06-2010, 10:36
  3. wot is overboost?
    By leegsi27 in forum Turbo Petrol Engines inc. Transmissions
    Replies: 9
    Last Post: 06-06-2009, 18:46

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •