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  • VXR 'ACTUAL' Power Figures

    Having read and seen a few VXR's on the rollers, have any of you had some decent figures from remaps etc?

    I know that the 237 figure quoted from the factory is a little optimistic and having seen the Total Vauxhall feature this month, I am surprised by the amount of people on here who quote 270+ etc from remaps and exhaust systems.

    Without being a little controversial I can understand that tuners who offer the remap may be a tad generous with the RR figures, as they have just sold the item. So has anyone been to other RR's and had standard/remaps etc figures quoted?

    Just interested thats all!

  • #2
    ive said before and i'll say again...

    as long as your happy with your power increase, who cares what it is!

    i mean say you picked yor car up from "tuner" and you where over the moon with the power, couldnt take the smile of your face and all that only to find out its actually 20 bhp less than you thought, would that make it less fun???

    power on paper cant be compared to having fun while driving.

    if your happy with your cars performance, then jack pot, if not get it tuned more :wink:
    stage 2 vxr

    [email protected]

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    • #3
      couldnt agree more Andy, but thats not exactly what I was getting at...

      I just wanted to know whether the figures were genuine (ish)

      Although I guess that you have answered my question by saying "I have said it before and I will say it again"

      Comment


      • #4
        the tuners figures quoted i think are a maximum you can expect.

        ive no doubt they are optimistic but id rather come out of the tuners with a happy feeling about my car than thinking right its got 310 brake but it could blow at any time lol.

        i know exactly what your saying but its always been the same. its a bit like these ads that claim you can add inches to your manhood by taking this pill twice a day.

        all i can go off is the fact that everyone on here seems happy with there cars performance after its had work done. all the tuners seem to get very good reviews regardless of power given.

        im looking forward to stage 3, but what ever power it is, i know im gonna be happy with it.
        :wink:

        i would be annoyed though if i got work done and it came out with less power
        stage 2 vxr

        [email protected]

        Comment


        • #5
          Very true.

          I guess that I am used to the C20LET figures being very realistic with the EDS etc chips.. sometimes even going over and above what was quoted by the tuning companies...

          Comment


          • #6
            Re: VXR 'ACTUAL' Power Figures

            Originally posted by willf
            Having read and seen a few VXR's on the rollers, have any of you had some decent figures from remaps etc?

            I know that the 237 figure quoted from the factory is a little optimistic and having seen the Total Vauxhall feature this month, I am surprised by the amount of people on here who quote 270+ etc from remaps and exhaust systems.

            Without being a little controversial I can understand that tuners who offer the remap may be a tad generous with the RR figures, as they have just sold the item. So has anyone been to other RR's and had standard/remaps etc figures quoted?

            Just interested thats all!
            How many times is this subject going to be debated

            The VXR engine, as all other production engines for that matter, is certified (a legal requirement) at a quoted power figure (C20LEH = 237bhp/240PS), which cannot be measured on a rolling road - it must be estimated via drivetrain drag on the rollers after a power run.

            The legal requirement necessitates that a sample of engines must be removed from the production line at random, at any time, by an independant assessor throughout the products life cycle and when tested must conform to this certified power figure within a defined tolerance - within -5% if my memeory serves me correctly although I will stand corrected if I am wrong here. On this basis, the lowest power figure a VXR C20LEH engine is legally certified to produce versus its certified quoted power level is ~225bhp.

            Now, this measured power figure at the flywheel will be obtained on a dedicated engine dyno with all necessary engine ancilliaries connected e.g. water pump etc but without any 'additional' ancilliaries connected such as air-con compressors. The power is then measured at the flywheel using a calibrated brake i.e. a calibrated load is applied to the engine which correlates to the engines power production across its operating rpm range.

            This power figure will therefore be an accurate, measured flywheel power figure - unlike the estimated one you get from a rolling road.

            The quoted 237bhp will therefore not be 'optimistic', but a figure representative of a majority of the engines produced (manufacturing tolerances ensuring that there will always be variation - the engine tolerance stack-ups being derived to ensure engines are produced within this '-5%' tolerance band regarding their power output).

            Assuming that there are no other issues that limit the potential of the engine to produce its power e.g. ECU problems, hardware problems etc etc

            Rolling roads are therefore not the last word in disproving manufacturers claimed power figures and certainly do not provide sufficient evidence to support a statement that Vauxhall is being 'optimistic' with its power figures.

            On this basis, there are are number of factors that can conspire to produce a low rolling road estimated flywheel power figures, or indeed a directly measured 'at-the-wheels' power figure:

            1. Crap rollers (poorly maintained, improperly calibrated etc)
            2. Insufficiently trained operators.
            3. Poor/inaccurate correction of data (i.e. all data should be corrected to standard day conditions (pressure, temperature and humidity) for accurate car vs. car comparisons.
            4. Poor quality (low octane) fuel.
            5. Air-con left switched on.
            6. Worn tyres.
            7. Over/underinflated tyres.
            8. Higher than normal drivetrain losses (?)
            9. Young, 'tight' engines (a 1000mile Vauxhall engine/drivetrain is nowhere near producing its full potential IME :wink: )...

            The list is endless.

            For 'before and after' modification e.g. remap, power gains on the same car on the same rolling road rollers are brill and a lot of fun - but nothing more.

            Rest assured, Vauxhall will be selling Astra VXR's with engines that are producing their claimed power figures within industry defined tolerances.

            An excellent example of how the legal requirements are managed within the industry is the original 2.0 16V engine in the Astra GTE 16V. This engine was originally certified at 156bhp without catalysts. When Vauxhall made the decision to fit the power sapping cats this quoted (certified) power figure dropped to 150bhp. Now, for the sake of 6bhp Vauxhall could have left the quoted power figure at 156bhp...couldn't they? No, they couldn't since the law did not allow them to claim inaccurate, uncertified power figures in the 1990's and it doesn't now. And that was just 6bhp (certification of engines is hugely expensive by the way...you wouldn't want to pay for it if you didn't have to...).

            Not having a 'go' - just getting really bored of the almost daily assertion on this forum that Vauxhall are in some way being dishonest about the claimed power figures for the C20LEH engine....

            Andy

            Comment


            • #7
              At last an answer that puts my mind at rest. Thank you Andy and well done.

              Comment


              • #8
                7. Over/underinflated tyres.
                8. Higher than normal drivetrain losses (?)
                9. Young, 'tight' engines (a 1000mile Vauxhall engine/drivetrain is nowhere near producing its full potential IME Wink )...
                10. Rear seats folded down

                Comment


                • #9
                  Very succinct from Andy, I think its 2% variance along 90% of the power delivery but I could be wrong there.

                  From our experience the standard car, assuming some decent miles on the clock is coming out almost exactly on the numbers, there have been some problem cars with issues that need ficing showing low numbers and some tight low mileage cars showing low numbers and some werid ones showing very high numbers but on average we see between 235bhp-2401bhp calculated at the flywheel.

                  Comment


                  • #10
                    2401bhp aye :wink:

                    Comment


                    • #11
                      2401bhp aye
                      crikey, someones just gone into orbit....around the sun

                      Comment


                      • #12
                        Well I havent seen a thread on the subject but I am a new member...

                        Why not make it a 'sticky' then if you are sooooooooooo bored of people asking the question.

                        Was not accusing or questioning Vauxhall's honesty or integrity, was just stating an observation/opinion.

                        Comment


                        • #13
                          That might be down to my mis interpreted thread a feww weeks ago wilf not you, neither was I but the world took offence at my inquisitive mind.

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