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Thread: Problems with Low boost/dropping offat high revs....

  
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    Silversport1's Avatar
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    Problems with Low boost/dropping offat high revs....

    Hi guys,

    I dyno'd my car today at Dynodynamics (known to be accurate dynos) and i'm pleased over all at the reult.

    My car ran 179.4 bhp with 190 ft/lbs of torque but the graph showed a problem with boost levels. Now my car is standard apart form a de-restricted Airbox& Panel filter and a Dump valve so wasn't expecting any different .


    It seems to be under powered and boost peaked at 2800 rpm at 0.6 bar and the fell down to just under 5 at the endo of the run with it running VERY rich last 1k RPM.

    Is this Normal boost level for Z20LET? I was told by the operator that upping the boost slightly to 0.9 would see it breaking the 200bhp mark easily (of which i am sceptical BTW).

    what should i do next- should i up the boost? and whow would i go about doing this safely?

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    Forgot to mention; It had a new turbo about 5K miles ago so i dunno whether the garage who changed it (before i got the car) set it to low boost, which could be possible i suppose...

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    Yea, thats deffinetely low for a zlet. Sounds like whoever put the turbo in didnt set the actuator up propperly so your loosing boost. Unless there are other underlying problems but if all seems ok and its just the boost playing up id put my money on the actuator, get that set propperly first then try again...

    p.s. if the actuator is up correctly and thats the only problem you should be no reason why it wouldnt hit around 200bhp :-)
    HTH
    Disastra Coupe Turbo - Chianti Red
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    Ok, Cool. thanks for that! I can't think of any other underlying problems. It's rescently had a new AFM and everything else seems hunky-dorey. Apart form the exhaust blowing i can't think of any reason it would be down on power (although exhaust the exhaust should make no difference).

    How would i go about adjusting the actuator?

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    Heres how to adjust the actuator taken from another thread.

    Quote Originally Posted by GeordieBandit
    loosen the top locking nut so its well out the way

    loosen the bottom one right the way down

    wastegate should now be able to move by pushing it with finger

    close it to its natural stop with ur finger

    wind the bottom nut up so it holds it in this position

    carefully wind the bottom nut 1 full turn (may wish to make a mark on one of the flats to see it move exactly 1 turn)

    leave it in this position and wind the top locking nut down to hold the wastegate in place

    DONE

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    Nice one mate, Thanks for that

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    did you take the fuse 23 out
    Arden Blue GSI And You Know Its The Best Colour To Have

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    Yeah the people doing the RR day did.

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    Silversport1's Avatar
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    Yes, it was pulled out. Also I've developed more problems since then;

    It drinks fuel like mad (managing about 15 to the gallon) and Turbo seems very loud now (past few hours).

    BTW i have NOT adjusted the boost yet, I'm waiting to sort a couple of other things and get a boost guage before i fettle with it lol

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