SR71 has answered pretty much most of the points i was going to cover in response and is correct:
before putting your faith in RR results over mfrs test claims you should read this, you will perhaps have a better understanding of the difference between an ENGINE dynometer and a CHASSIC dynometer
http://www.pumaracing.co.uk/POWER3.htm
As pointed out by the article and by SR71 ALL makers including BMW, PORSCHE, FERRARI and all the F1 teams test their engines in a engine test cell, these cells cost several million pounds are a controlled test environment where the engine is put on a mount and every aspect of its operation from fuelling, lubrication, cooling and air quality, ambient temperature can be set precisely within a tolerance. The maker will use fuel that is certified for its octane rating, oil that is certified for its viscosity, spark plugs etc etc all to a exact tolerant standard. The tests are then run by a industry standard piece of SW that runs specific test programs on an engine. To generate the figure they use they will do runs on a selection of engines from random batches and take an average median of the results.
Due to the way in which engines are now computer designed and machined the tolerance of error in each engine will be less than 0.5 percent from the design with 0.1 percent or better typical of modern laser measured CNC type lathes - given that Audi will have stress tested the engine running up to 500bhp and then output the engine at 20-25 percent less than its maximum stressed output to improve service life and running costs you can be fairly sure the 414bhp figure will be on the numbers.
Trying to discredit a multi-million pound test facility with state of the art ISO standard measuring equipment and processes carried out by Engineers with PHD's and years of test experience is going to be a hard call even if you decide to give someone like Ricardo 1 million quid to run tests to the same tolerances to be admissable as evidence.
YOu are not comparing like for like SR71 is perfectly correct that using a chassis dyno to back calculate engine output is the equivelent of guessing how much flour is in a cake after its baked. Since you don't have a veriifed set of figures for transmission loss which can vary down to the test conditions you cannot accurately calculate power at the flywheel without having a precise figure for the chassic as well which you could only calculate by having a certified result for the engine to work from.
RR's are good as useless at calculating engine output, you can only take relative measurements - i.e gains between the at the wheels measurements you cannot produce absoloute figures for the engine since you have too many variables.
most RR sessions are carried out in industrial sheds, with variable temperatures, using variable quality of fuel that was pumped from a PFS that may have sediment or water in its tanks, your oil is in a unknown state of degradation, your spark plugs are in a unknown state of degradation, you have no way of knowing how accurately the chassis dyno has been calculated or that the figures used for transmission losses in any way represent the actual losses, as a result its unlikely you could reproduce the same result 20 times on one car within the same degree of tolerance that audi could on their engine test cell. therefore your "evidence" will not be of a sufficient standard to meet international test validations and therefore is just not credible.
SR71 is correct to state that if you wanted to pursue this case then Audi can quite rightly expect the engine to be lifted and taken to quattro and be put on a test cell and tested under the IDENTICAL conditions to the ones they generated their original figure from, and the likelihood is your engine will be putting out between 410-420bhp depending on its mileage and wear and level of carbon build up.
The variations in "Power" that are being mooted are based on highly suspect RR test sessions that have no substance - you cannot say for certain any of them have used accurate transmission loss calculations to generate an exact figure, given the nature of modern engine control that adjusts fuelling according to ambient temperature, air quality, oil quality, fuel quality et al then it stands to reason that all engines including Porsches, FErrari, BMW et al will offer a variable amount of power output according to operating environment, its a known fact that F1 engines can lose as much as 100 or more BHP in places like brazil due to high ambient air temperature and therefore low air density - this is an accepted point of motor engineering and beyond Audi's control.
If you read the wording of the performance claims it clearly states MAXIMUM POWER output, i.e the maximum the engine will prdocue under a certain set of ambient operating conditions, this is not a cast iron warranty from Audi (or BMW or PORSCHE) that you are going to get 414BHP regardless of conditions.
The RS4 engine is a highly technical racing spec engine, in commonw ith such engines it uses variable fuel mapping and controls to ensure the engine is always delivering its optimum performance based on operating temperature, intake density etc and therfore its natural that it will vary its power output. But this will also affect all other modern NA engines such as the new M3 unit as well, its less perveland in forced induction since supercharging or turbocharging is forced induction and you are less reliant on natural air density to deliver power.
As for people suggesting quattro's higher transmission losses over BMW's leads to more ""Lost power" - this is an acceptable part of chassic engineering, while the M3 loses less power in transmission the RS4 offers more mechanical grip and therefore traction so its transmission loss is vastly compensated by the amount of power it can deliver to traction as opposed to simply spinning the wheels and losing grip.
You are honestly wasting your time with this, there is no smoke and mirrors, no grand conspiracy that audi are nobbling engines, and no misdescription, just the usual incorrect belief that you can accurately measure engine power with a CHASSIS dyno which is usually caused by RR operators keen to sell their services not fully explaining the fact most of the figures they use are simply guesses.
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