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Thread: STILL not holding enough boost!

  
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    jstanley's Avatar
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    STILL not holding enough boost!

    Hi, my astra gsi regal stage 2 doesnt seem to hold enough boost. Overboosts to about 15 & slowly drops to about 8psi. All vacuum hoses at rear of engine are good, bypassed rear bcs & vac box, & today ive fitted a collins -31 actuator. After fitting the -31 it seems to overboost to about 16-17psi & still drops to about 8psi ish. What else can i try guys? Please help. Thanks

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    jalfrezigazee's Avatar
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    a new boost gauge perhaps!! Have you had these figures checked by a tuner? Also are you on standard IC? Is it clear of obstructions?

    If the intake temps are high then the system will pull back boost
    Be Happy


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    thrifty's Avatar
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    Cracked manifold by the waste gate?
    I had this and only found it when I changed my turbo, but I was losing boost.

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    Are you using a dump valve? If so take it off and plug up the hole with something and give the car a run. What's the vacuum like on idle? Should be around 20-22 inhg anything less there's a leak somewhere. Changed the boost sensors?

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    Ive got a tx intercooler mate. Yeah i have a baileys dv, would you not hear it if it was leaking? My guage on idle shows about 18-20inhg.
    If it was cracked how would i see it? By taking decat precat off?
    Could the front bcs cause this? If so might but one tommorow. Thanks.

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    Vacuum sounds ok so it must be the boost hoses, check all hose clips are tight. Borrow a boost sensor from someone in your region if you can to rule out a duff sensor

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    Found the problem. Turbo was reconed just before i bought the car last may, but as you can see by the pic whoever reconed it has tried welding over the crack,lol, no wonder its never held boost since i bought the car. Thanks for your help guys.



    Vxr turbo time now, then stage 3.

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