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    Anyone Dyno'd a 997S X51?

    I have read somewhere that Porsche take the top output engines to add the powerkit too, so that they make at least the 381 bhp they say. No idea if this is true or just one of those forum rumours, but I have not read anywhere of anyone that has dyno'd an X51, anyone done this?..it would be interesting to see the outputs on a few to verify or dispel this myth

    Re: Anyone Dyno'd a 997S X51?

    i have some parts of the X51 kit,..the aluminium intake manifold,the carbon airbox and the bigger throttle...but i install another headers-cats-muffler plus new s/w...so the result was quite well...i have the dynosheet but the file is too big and i cant post it here,i can send it to you via email if you wish...or can anyone help me to attach it here?

    Re: Anyone Dyno'd a 997S X51?

    Interesting combo that definitely has appeal. I would love to see the dyno sheets. How much did Porsche charge for the CF airbox?

    Re: Anyone Dyno'd a 997S X51?

    I can't comment on the possible rumours but what I have been told, when I went on the factory tour in Stuttgart, is this: PAG produces engines which are a minimum of the advertised bhp but with a maximum of 4% more than this. Every engine is bench tested for around 30 minutes once assembled before it is installed in a car. If an engine produces less than the advertised output, it is taken apart and re-assembled by a different assembler to make sure it produces the minimum it is supposed to produce. PAG also has a quiet word with the assembler who prepared the engine that was low on power to identify why this was the case. He isn't in trouble - it's just to get to the cause of the problem.

    So, for example, a C2S engine should have a mimimum of 355bhp but may have up to 369.2 bhp.

    AFAIK PAG does not put aside engines which produce more than the minimum for customers who opted for X51. X51 is supposed to add 26bhp. It is possible therefore for a X51 car to have 355 + 26 =< x =< 396.24 bhp.

    BTW if an engine produces more than 4% over the minimum, PAG also dismantles these. They do not want to provide engines which burn out prematurely.

    Note also that PAG stopped putting the name/initials of particular engine assemblers on the engines. They had past customers who would dyno their car and then ask for a particular assembler when ordering their next car to get a few more bhp.

    Re: Anyone Dyno'd a 997S X51?

    Easy on the opportunity of your post I noticed you've just touched the tip of the iceberg, namely engine output measurement and consequently production quality control. What you were told by PAG is a superficial description of probably the most highly regarded process in the automotive industry, the quality checks that are directly related to the reliability and the reputation of a marque. But for an engineer like myself their relatively simplistic approach doesn't hold but a part of the whole true so let's try to find out what really happens.

    Your host at the day of delivery tried to summarize in a few words and in broad terms the statistical sampling test of the power units to be delivered. But let's take into account that they DON'T actually dyno each one of them. This is an ultra-expensive process, time consunimg approach and in no way efficient neither for PAG nor for us that immediately after the delivery start the breaking-in period.

    Imagine how embarassing we would all be feeling if the absolutely fantastic care we take in the break-in period had to be reconsidered in the view of a dyno test measurement across the minimun/maximum values of the rpm range

    What they do practice is the following> Each time the engine assembler have a population of units delivered to the manufacturing plant, PAG engineers randomly pick a predefined number, called sample, as to perform a probability test. Those and ONLY those units go through an exhaustive testing process for the engineers among many-many other tasks to dyno them in the scope of preparing the quality sheet of the assembler production. According to that testing process they calculate the interval confidence of usually 5%-95%(i.e. the range that the power output of that specific population of engines will be falling into).

    For the remaining of the non-exhaustively tested engines population and prior to be mounted onto the chassis the technicians actually check a set of some critical values (e.g. cylinder compartment compression) to see if they do comply with the originally set indexes.

    However, in today's highly sophisticated production processes the +/- 4% in power flactuation seems to me extremely broad, especially for such a newly-designed unit that takes pride for being at the top of the naturally aspirated special power rank (hp/lt). Almost 10 years back when I used to work for Ferrari that value wasn't supposed to be more than +/- 1,5%. And pls believe me, those Ferrari units were only skeletons compared to the standards of the nowdays manufacturing technology .

    Last but not least, things regarding the accuracy of any power measurement get even more complicated if only a couple of parameters such as atmospheric temperature, pressure and weather conditions get into the play. Does anyone believe that the same engine unit will be constantly delivering a typical maximum power value if measured once in summer and once in winter. Not a chance in a billion!

    Sorry for getting so boring for many of us here, believe it or not I really tried to cut a long story short.

    Re: Anyone Dyno'd a 997S X51?

    Excellent analysis. As a software engineer I can agree that your description seems logical.
    Thanks,
    Beers on me.

    Re: Anyone Dyno'd a 997S X51?

    I "think" what actualy happens is the following:

    A number of"blind" test engines are added to the regular production quantities. The identity of the particular test engines is know only to the QC managemant.

    When said test engines are completed, they are pulled from the line for inspection, conformity to specifications and tear down. Results are then cycled back through the system. It is all done on a statistically valid basis.

    Re: Anyone Dyno'd a 997S X51?

    Beers on you at Kansas, dyno on me next time you're in Athens.


    Which do you prefer first?

    Re: Anyone Dyno'd a 997S X51?

    May be it works this way, may be some other. Each manufacturer rules its own testing pattern and scenarios, so there should be huge differences as to comply with the objectives each one has set up.

    What I'm trying to make clear is just the foundation for understanding the probabilistic and statistical approach that is scientifically accepted no matter the objective or the manucafturer.

    Re: Anyone Dyno'd a 997S X51?

    Quote:
    Leawood911 said:
    Excellent analysis. As a software engineer I can agree that your description seems logical.
    Thanks,
    Beers on me.



    I'm not an engineer but I think I understand too.

    Re: Anyone Dyno'd a 997S X51?

    Quote:
    Hollli82 said:
    Quote:
    Leawood911 said:
    Excellent analysis. As a software engineer I can agree that your description seems logical.
    Thanks,
    Beers on me.



    I'm not an engineer but I think I understand too.



    I'm not an engineer also + I'm technically challenged and even I understood it Very nice summary of the process

    Re: Anyone Dyno'd a 997S X51?

    The question is:
    - do they use statistical sampling for quality control;
    - do they actually dyno every engine like they tell visitors;
    - do they do both (e.g., statistical sampling for more in-depth QC such as teardowns)?

    Re: Anyone Dyno'd a 997S X51?

    Each engine is assembled for a particular car (VIN)
    There are no off the shelf engines.

    Each engine is tested on the dyno as the last step in the assembly process.
    If min standards are not met thee is a 'teardown area' to identify/rectify the reason for the failure.

    The results become part of each cars dossier.


    Re: Anyone Dyno'd a 997S X51?

    Interesting approach!

    So it'd be brilliant whether you could share wiht us all what your own dossier states about your peak engine performance

    Re: Anyone Dyno'd a 997S X51?

    function_analysi,

    I agree with everything you wrote - since this is clearly an area where you know exactly what you're talking about - but there's just one thing that Trundle_GT3 mentioned where I respectfully disagree with you. When I went on the factory tour, the tour guide, Peter Markov, stated expressly that they test EVERY engine for at least 30 minutes, not just a sample.

    If they also do more in-depth testing on a sample IN ADDITION to what little they do on each engine, then what you're saying makes complete sense.

    I'm no expert on this like you. I'm just passing on what they told me in clear and unambiguous language.

    Re: Anyone Dyno'd a 997S X51?

    Yet again disagreement in the ranks. Read the scientific post about sampling engines and how its too expensive to dyno all of them....all sounded reasonable to me, then Trundle says they are all dyno'd...One of them is wrong, and it makes it very hard to believe. It would be far better if people actually dealt in facts rather than opinions or hearsay or rumours etc....becuase now from thinking I had the answet Im back to square one!!which version is right?...

    Re: Anyone Dyno'd a 997S X51?

    It does sound like a mammoth task to test EVERY engine they produce. How many are produced each day?

    Re: Anyone Dyno'd a 997S X51?

    160 911s are made every day. I've seen them doing it. I've stood outside the very room where they carry out tests on every engine. They wouldn't let us inside - they are controlled environments. I've even seen the benches where they dismantle engines that aren't working right.

    Guys, I'm just telling you what the Porsche factory told me and what I saw with my own eyes in Zuffenhausen.

    Re: Anyone Dyno'd a 997S X51?

    Quote:
    Chris5150 said:
    Yet again disagreement in the ranks. Read the scientific post about sampling engines and how its too expensive to dyno all of them....all sounded reasonable to me, then Trundle says they are all dyno'd...One of them is wrong, and it makes it very hard to believe.



    Maybe it's just a confusion with the technical terms. I can't really help to dissolve the seemingly contradiction as neither my skills in "tech English" nor my technical knowledge is sufficient.
    BUT one thing is for sure: just like Easy said each and every engine is tested in Zuffenhausen (at least that's what the factory guys tell you during the factory tour and you can see the test benches through a window). Whether these tests (simply spoken: they "run" the engine) is exactly the same test programm like a "dyno run" is another question, which I can't answer. Maybe the tech experts can chime in here to dissolve the seemingly contradiction.

    Re: Anyone Dyno'd a 997S X51?

    Quote:
    easy_rider911 said:
    160 911s are made every day. I've seen them doing it. I've stood outside the very room where they carry out tests on every engine. They wouldn't let us inside - they are controlled environments. I've even seen the benches where they dismantle engines that aren't working right.

    Guys, I'm just telling you what the Porsche factory told me and what I saw with my own eyes in Zuffenhausen.



    I've seen it as well....
    The last station of the engine assembly line, engines are fitted with adapters, filled with oil and then proceed to the next station, the dyno room.
    The motor is then hooked up to the Dyno in a sound proof room, and put through the paces for 30 minutes. Porsche refers to this as the "Hot Test".

    The following hot test is the final step in the engine production process. The engines are first of all heated up to operating temperature and then subjected to a functional test including full-throttle testing. Information in the form of up to 220 parameters is generated in this test of around five minutes' duration.

    The engine must produce at least 100% of it's rated horsepower, or it is unacceptable.

    Each and every engine assembled gets dynoed

    Each engine is assembled for a particular car by one tech.

    Re: Anyone Dyno'd a 997S X51?

    Exactly I couldn't have explained it any better myself. Your recollection of the tour is extremely accurate...

    Re: Anyone Dyno'd a 997S X51?

    Gents, thank you all for your kind input those who did agree and mainly those who respectfully disagree.

    To start things on the right foot I just want to mention that what I tried to offer wasn't a deep insight view of the PAG quality control process but a basic fundamental yet scientific knowledge, and as such it can be applied in any production process. Once you have the fundamentals down, you can confidently apply them to any production process that comes along. However, as already stated each manufacturer rules its own testing pattern and scenarios, so there should be huge differences as to comply with the particulat objectives each one has set up.

    For in depth specifics regarding the actual procedure followed by PAG on this matter it is recommended to ask directly the external relations office.

    I do not intend neither to strike a nerve end nor to comment on personal views/rumours/speculations. But there are a few things I'd like you to know.

    @ Porsche-Jeck
    You've pointed out the most critical aspect of this issue i.e. the difference between 'run' the engine unit and 'dyno' the engine unit. By definition ALL engine units should be run prior to have them mounted onto the chassis, no objection on this. Out of that the technicians get the 220 points report as someone said.

    But dyno is another thing. By definition dyno is performed at the wheel not at the engine crankshaft, so even if they redline the engines for a few minutes they don't dyno them Always remember and according to the witnesses this test is being performed on a bench, that said it's a bench-test, so dyno is out of question.

    @EasyRider
    Firstly, hope your yesternight's drive was both exciting and productive in terms of mileage Thanks anyway for your nice compliments, I appreciate it!

    As regards your tour guide he only told you that PAG 'tests' every engine, not 'dyno' each unit. BTW the tour guide isn't an well-learned person just a hard-working employee that is trying to do his best and disemminate the messages they were trained to. They simply dictate a script/scenario/FAQs that has nothing to do with the terminology and the rigour of the quality process in itself.

    At this point let's try to touch a common base on the terminology as to better understand what's really happening.
    Such a 220 points 'control' -I'd in no case call this as testing- is with no doubt part of the manufacturer's quality process.

    At your end, you also clarify quite well the essence of our discussion just by devising the control phase that they do apply to each and every engine -the population we were discussing the other time- from the testing phase that is an essential statistical/probabilistic exercise for only a few randomly selected units -the samples we were discussing.

    @Chris5150
    Rome wasn't built in a day so don't expect yourself to embody such kind of embedded knowledge in a quick and dirty way just by reading posts in forums like that. What we are taliking here is about applied scientific models and as such believe me it's not easy for anyone to familiarize himself simply by using his common sense or by trying to interpret the popularized theories of a tour guide. Don't know what your job is but think how fast would somebody get into the details of it. Normally it takes more that common sense, it also requires effort, headaches, overtime but basically time.

    @BoxsterBoy+EasyRider (again)
    All in all PAG manufactures annualy 100k units -full range of models- or approximately 277 cars every day. Probably 160 out of them are 911s (plural, not the 's' model) so take into account that according to their quality plan they should be bench-testing all of those engine units. Imagine now how tougher this would be if they were to actually dyno them.

    @TrundleGT
    Seeing is not always believing. Bench-testing isn't dyno-testing for all of the reasons explained before.
    Hot testing doesn't equal dyno-testing as well. Besides, for a manufacturer to check whether a unit performs according to the specified indices or not he doesn't need to redline it. The engine works in a range between 600-7500+ rpm, so what they are really interested in is to see how the unit performs in that spectrum let alone the red line. Chances are (probabilistic approach again) that if an engine doesn't deliver well in low/mid-range won't also perform the expected nominal horsepower in the redline. This also works the other way, i.e. provided it delivers the nominal bench hp doesn't equal to the statement that the engine is qualified for mounting

    BTW, I'm still waiting for your car's dossier stating the actual horsepower of your bench-tested engine.


    Re: Anyone Dyno'd a 997S X51?



    I've seen it as well....
    The last station of the engine assembly line, engines are fitted with adapters, filled with oil and then proceed to the next station, the dyno room.
    The motor is then hooked up to the Dyno in a sound proof room, and put through the paces for 30 minutes. Porsche refers to this as the "Hot Test".

    The following hot test is the final step in the engine production process. The engines are first of all heated up to operating temperature and then subjected to a functional test including full-throttle testing. Information in the form of up to 220 parameters is generated in this test of around five minutes' duration.

    The engine must produce at least 100% of it's rated horsepower, or it is unacceptable.

    Each and every engine assembled gets dynoed

    Each engine is assembled for a particular car by one tech.



    That is exactly what I witnessed when I went thru the factory tour

    Re: Anyone Dyno'd a 997S X51?

    I don't want to get into this (as I have little knowledge of the factories workings with this) BUT you most certainly can have a Dyno done at the crank and not just at the wheels. IN FACT there are inherent problems with getting dyno numbers at the wheels 9parasitic drag from gears, aux systems etc.) It is MUCH prefered to run a dyno test off the crank on the bench.

    I just don't see how they would want to red-line the engine without the break-in process and without seating the valves etc. If an engine makes 355bhp when it's 5 minutes old, it will make more at 5000 miles...

    Re: Anyone Dyno'd a 997S X51?

    Excellent point Mithras.

    In the old days dynos were configured as to measure brake horse power (bhp) at the wheel, so historically that category of dynos is fully named after 'chassis dynamometre'

    Today modern dynos can also be found for bench testing applications as to measure torque (and consequently convert it to power) at the engine crankshaft. Correctly as you said engine dynos don't account for any of the power losses appearing in the drivetrain.

    Re: Anyone Dyno'd a 997S X51?

    Quote:
    Mithras said:
    I don't want to get into this (as I have little knowledge of the factories workings with this) BUT you most certainly can have a Dyno done at the crank and not just at the wheels. IN FACT there are inherent problems with getting dyno numbers at the wheels 9parasitic drag from gears, aux systems etc.) It is MUCH prefered to run a dyno test off the crank on the bench.

    I just don't see how they would want to red-line the engine without the break-in process and without seating the valves etc. If an engine makes 355bhp when it's 5 minutes old, it will make more at 5000 miles...



    I agree. My car is loads quicker now than when new. So do I have 400 BHP now?

    Re: Anyone Dyno'd a 997S X51?

    Quote:
    function_analysi said:
    But dyno is another thing. By definition dyno is performed at the wheel not at the engine crankshaft, so even if they redline the engines for a few minutes they don't dyno them Always remember and according to the witnesses this test is being performed on a bench, that said it's a bench-test, so dyno is out of question.



    By definition, a dynamometer is a device for measuring an engine's mechanical power output. Dynamometers predate cars, as they were used in more primitive forms to measure the power output of stationary engines, including steam engines. They "measured" power at the flywheel, effectively crankshaft power. I believe that they were called "engine test benches" in English in earlier times and suspect that the name "dynamometer" only became current later when the mechanical friction brakes (as in "brake" horse power) were replaced by an electrical generator.

    The measurement of power at the road wheels came later and these test rigs were referred to as "chassis dynamometers" to differentiate them from real engine dynamometers.

    Engine test benches actually measured work done over a given time and derived the power output from that result by calculation. Modern dynos measure torque output at a given engine speed and derive the power output from those two values.

    Quote:
    function_analysi said:
    As regards your tour guide he only told you that PAG 'tests' every engine, not 'dyno' each unit.

    At this point let's try to touch a common base on the terminology as to better understand what's really happening.


    @BoxsterBoy+EasyRider (again)
    All in all PAG manufactures annualy 100k units -full range of models- or approximately 277 cars every day. Probably 160 out of them are 911s (plural, not the 's' model) so take into account that according to their quality plan they should be bench-testing all of those engine units. Imagine now how tougher this would be if they were to actually dyno them.


    In my view, "dyno"ing an engine involves carrying out power output measurements on a dynamometer, which can be done very quickly once the engine has warmed up.
    You seem to be thinking in terms of tuning an engine on a dyno, involving adjusting parameters such as air/fuel mixture and ignition timing. This would be a much longer process.

    Quote:
    function_analysi said:
    @TrundleGT
    BTW, I'm still waiting for your car's dossier stating the actual horsepower of your bench-tested engine.



    The fact that a manufacturer keeps a dossier on test data of its individual products as Trundle stated does not mean that it passes this data on to its customers. I can think of good reasons why it would not do so.

    Re: Anyone Dyno'd a 997S X51?

    Fair point Fritz. You historical overview on the development of the dynamometre is quite excellent.

    (OBTW, is a combined term fully originating from Greek made up of the word dynamo=dynamis=force and meter=measurement)

    Apart from your contribution that anyway isn't the essence of our discussion any idea on the actual process followed by PAG? Do they actually dyno/bench test each one unit up to the red line or not?

    We all appreciate your input.

    HAK

     
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