[Boss330]

Originally Posted by solstice

Why do you by default and conviction assume that the MAHA dyno is inconsistent? Why can't it just as well be the stated hp that is "inconsistent" vs a potentially true measured/calculated MAHA hp? In a way I wish I still shared your full and complete trust in the precision and perfection of authorities and regulators...but I don't.

It's not about the "precision and perfection" of authorities and regulators. They don't make the cars... It's whether the manufacturers and independent technical services are complying with the legislation they are giving their legally binding assurance that they comply with!

And the factory stated HP is measured on a multi million engine dyno certified to do that. Seems like many by default and conviction assume those dyno tests are inconsistent. NO chassis dyno is certified to measure crank hp...

We can either choose to believe a chassis dyno that is not certified to measure crank hp and which we we have plenty of evidence has a variation of 10-15% between them. Or, we can choose to believe the independently measured hp numbers taken on a engine dyno at a technical service.

For me, the choice is really easy Especially when trap speeds/performance also match the factory stated hp number!

Even the OP (P1) of this thread admitted that the S55's average power of 425HP "quite possibly" could explain the trap speed of the F8x... Shouldn't that be a hint that there might be questions about the OP's simulations, when he hadn't given any thought to the difference in average power of the S55 vs S65? And him being honest enough to agree that this "quite possibly" could account for the difference?


I know you don't put much trust in regulators and the manufacturers ability or willingness to comply , but for information for the rest of us I will just post what Directive 2007/46/EC says about conformity:

http://eur-lex.europa.eu/legal-conte...140101&from=EN" rel="" target="_blank">http://<a href="http://eur-lex.europ...01&from=EN</a>

In order to ensure that the procedure for monitoring conformity
of production, which is one of the cornerstones of the
Community type-approval system, has been correctly implemented
and functions properly, manufacturers should be
regularly checked by the competent authority or by an appropriately
qualified technical service appointed for that purpose.

1. The manufacturer is responsible to the approval authority for all aspects of the approval process and for ensuring conformity of production, whether or not the manufacturer is directly involved in all stages of the construction of a vehicle, system, component or separate technical unit.

1. The Member State which grants an EC type-approval shall take the necessary measures in accordance with Annex X to verify, if need be in cooperation with the approval authorities of the other Member States, that adequate arrangements have been made to ensure that production vehicles, systems, components or separate technical units, as the case may be, conform to the approved type.

2. The Member State which has granted an EC type-approval shall take the necessary measures in accordance with Annex X in relation to that approval to verify, if need be in cooperation with the approval authorities of the other Member States, that the arrangements referred to in paragraph 1 continue to be adequate and that production vehicles, systems, components or separate technical units, as the case may be, continue to conform to the approved type. Verification to ensure that products conform to the approved type shall be limited to the procedures set out in Annex X and in those regulatory acts that contain specific requirements. To that end, the approval authority of the Member State which has granted the EC type- approval may carry out any of the checks or tests prescribed in any of the regulatory acts listed in Annex IV or Annex XI on samples taken in the premises of the manufacturer, including production facilities.

3. When a Member State which has granted an EC type-approval establishes that the arrangements referred to in paragraph 1 are not being applied, deviate significantly from the arrangements and control plans agreed, or have ceased to be applied, although production is not discontinued, that Member State shall take the necessary measures, including the withdrawal of the type-approval, to ensure that the conformity of production procedure is followed correctly.

I might be naive, but I find it very unlikely that a European manufacturer deliberately and knowingly deceives and misleads EU type approval authorities. There is a regime to verify conformity, including spot checks at random. So the risk of being caught cheating definitely is present! And with all the forum activity about under rating, the good people responsible for those spot checks might find it relevant to do a spot check on engine power... (Lot's of those working in the auto industry, on both sides of the "fence", are car enthusiasts reading forums like these (posting as well perhaps )...). That is something BMW obviously will need to have considered as a possibility if they have indeed under rated their engines to the extent it's claimed here.

And, no I also don't believe that there is a mysterious factor inside, or outside, the dyno room explaining a "legal" difference of 60-70hp. It would also be strange that that factor only should be present on the S55... If anything, the dyno room is a ideal environment and should not yield lower power ratings.

Let me also add that this isn't proof of no underrating, merely evidence based on a regime of testing, compliance and spot checks to verify that compliance.

And, another (unrelated to this thread) interesting legal requirement:

It is also important for equipment manufacturers to have access to
certain information that is available only from the vehicle manufacturer,
that is to say, the technical information, including
drawings, required for the development of parts for the aftermarket.