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  1. #1
    VXR newbie
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    16th September 2016
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    Default Low BHP after Insignia VXR turbo, VXR injectors, full decat and remap upgrade

    Hi guys,
    Vectra 2.8 owner here. I need opinions and advices. Here is mine Dyno print out:



    Mods done to car: new Insignia VXR turbo, new Insignia VXR injectors, full decat, new coils and new regapped spark plugs to 0.75. Remap done by reputable tuner.
    Car seems too low on bhp and torq, by mods done. Where should i start to look for issues?
    Tuner says the same tune on similar Vectra gave 330bhp and over 600nm of torqe. Says it is not tune problem.

  2. #2
    z28 open block surgeon nick150's Avatar
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    1st April 2012
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    3,476

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    What's the year
    Mileage
    Has it had the chains done
    NOW STAGE 3 BUILT BUY ME POWERED BY SUPERCHIPS.
    INSIGNIA TURBO,INSIGNIA INJECTORS,QUAFE DIF,PADAL CLUTCH,COURTNEY RAD AND INTERCOOLER,3 INCH SYSTEM,BILSTEN B12'S,AP RACING BRAKES,POWERFLEX BUSHES

  3. #3
    VXR newbie
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    16th September 2016
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    2008-03, Mileage 40000, no chains done or ratlling. Oil changed every 3000 miles. Overal car is in perfect condition except this.

  4. #4
    VXRed blooded
    Join Date
    11th July 2014
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    Nick will know better than most whether the 08 cars had chain issues or not. I can only talk about my chain issues on an 2007/07 car - the chains went after just 57k and the vehicle had full Vauxhall history. I got Nick to buy me the chain kit from USA and had my mechanic fit everything. After just a rebuild, with zero mods the car made just over 287bhp at the flywheel (engine power). Do you have a baseline engine health figure to work with, by this I mean before any modding started, do you have a dyno graph to share? If not then the situation is made difficult because you could have been well down on power as standard.

    The tuner is correct, around 330bhp is possible for the mods listed. By full decat I assume you mean precat and main cat removal? Without knowing more then I can only suggest chain issue or boost leak, boost leaks fairly common. Who is the tuner out of curiosity?

  5. #5
    VXR newbie
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    16th September 2016
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    No, unfortunelly i dont have the baseline dyno. Yes full decat, i mean precat and main cat are removed. As i understand and from my expierence with chained engines, chains start to rattle first. There are no heard ratlle on my car. In order to check the boost leaks, should i check all the junctions from turbocharger up to intake manifold? Is there a way to catch intercooler leak if it is somehow leaking? Could intercooler leak cause this type of power loss?
    Thank you for ideas, it is good food for thoughts

  6. #6
    VXRed blooded
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    11th July 2014
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    The problems with chains is that there is sometimes no warning when they are on their way out, meaning no warning lights or rattles, this is why a baseline would have been useful as it would have given an indication of general engine health. If you are on Facebook then apply to join the closed group Vectra VXR Owners. One of the members works at MWP (MW Performance) in Chester, who like Nick have become a chain specialist. His name is Matt Duffield. I'm not sure where you are based but if you could get your car to Nick or MWP, both North West England then perhaps they can help. I'm not sure what or where to check for a boost leak. Did the tuning company not give you any feedback on what might be wrong? Did they provide an AFR (air fuel ratio) graph too? Sometimes a misfire can't be heard or felt on the road but is picked up on the dyno, was there any feedback about strange noises etc?

  7. #7
    VXR newbie
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    16th September 2016
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    I am not in UK. Afr graphs looks ok, stays 11-12 most of the time, though max throtlle may drop it up to 10.5 for moment. No strange noises or misfires. Tuner hinted to turbo problem and suggested to hybrid it to 20T, but it is new Insignia VXR turbocharger, i am not willing to hybrid it. I could have done it on stock turbocharger, but it is gone and money spent on Insignia one.
    I will work with boost leak idea, it may have something with this issue.

  8. #8
    VXRed
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    15th May 2016
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    It would be handy of that graph had boost on it.

  9. #9
    VXR newbie
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    Yep, but unfortunely it does not have it. Anyway it would be number from ECU via OBD and i can read that with ***** or simple elm reader.

  10. #10
    VXRed
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    That's where I would start.

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