DYNO Experiment - Why power can be down on a dyno...

Simon,

Sorry, but I feel you too have missed the point. I posted my experimental data for one reason only, and that was to demonstrate that with this particular car, on this particular dyno, the boost was 0.2 bar lower than on the road. Even the exact power reading was not important at this stage.

Several people, including yourself, chose to imply some hidden agenda here, which to be honest I'm really disappointed by this. It has nothing to do with winning, nothing to do with competition, and nothing to do with anyone elses car! I couldn't give a flying fish about PE, TME, or Phil's T5R, IN THE CONTEXT OF THIS THREAD.

To say that this won't advance the knowledge of anyone proves that the point has been missed. In fact it DOES advance knowledge IF you read my initial post with the experimental results and try to understand what is going on.

I will be posting more experimental data in the future for INTERESTED PARTIES. If you do not fall into the category of INTERESTED PARTY, or have nothing constructive to contribute about the experiment itself, please don't bother posting, and steering the thread into a slagging match in the future.

Adam.

[IC]

Adam, you have made some excellent contributions over quite a long time on our fora helping people with their problems and updating us with the latest data that you feel would interest the reader - I do appreciate your contributions and the time that you take to help people with all things technical. I do think that it is important that members are informed of new products and services and would support all providers in providing invaluable information to us all, however please do not shout at a VOC official when replying to a thread as it is completely inappropriate, even when the information being discussed is not directly associated with any VOC matter.

I appreciate that you have tried to present information to interested parties and you had good intent in doing so. There is indeed nothing wrong with healthy debate and dialogue - I do appreciate that there is not a single previous occasion when you have replied in an inappropriate manner. I look forward to your continuing contributions.

>Rooster, it was 250 bhp @ THE WHEELS @ 6000 rpm when down by
>0.2 bar.
>
>Adam.
Hi Adam how exactly did you calculate the above quoted figure ? I have read a thread from yourself minutes ago on another volvo forum which clearly explains that any rolling road tests caried out with the engine in a car cannot give accurate at the wheels bhp figures due to unknown transmission loss and also refers to guess work over these figures.Is this your guesswork or are you prepared to offer the dyno printout for the said car or any car you chip for that matter so that some more accurate figures can be obtained. Also please supply all management parameters at said power readings, you have vadis so these can be provided, ie intake air temp, maf voltage, injector times, boost pressure etc etc. As you should know these details will provide the information to tell infact weather or not there was a poor inlet air temp at the rolling road or not. The thread i refer to can be found here.


http://volvo-t5.co.uk/phpbb/viewtopi...autos&start=15

Once all the above details have been provided on the forum anyone will be able to comment on your statements and hopefully attempt to substantiate your statements regarding rica chipping and true bhp readings.

ps a copy of the dyno calibration certificate will need posting up.

I await your response eagerly

thanks stuart

>however please do
>not shout at a VOC official when replying to a thread as it is
>completely inappropriate, even when the information being
>discussed is not directly associated with any VOC matter.

Iain,

I appreciate your comment and understand that some people are easily offended, especially on the net where emotions cannot easily be expressed. However we are all grown ups here. VOC "official" or not, Simon missed the point, and therefore it was entirely appropriate to emphasise the purpose of the post again. Since I don't know how to write in bold characters on this forum, I used caps as an alternative, which has apparently been misconstrued as shouting.

So to prevent further confusion, if someone can show me how to write in bold characters, I would be very greatful.

Thanks!
Adam.

[Bob]

The accepted way of emphasising a word/words without using capital letters is to put an asterisk either side, like so: *hello*.

Bob
_____________________________
Robert Isaac
Volvo Owners Club
Director and Web Admin

Stuart,

Although I don't know you, or your level of experience with tuning cars and using dynos, I want to shed some light here -

1. A dyno measures power (or more precisely torque) at the wheels. It does not calculate power at the wheels - it measures it. Power at the flywheel however *is* calculated, by measuring drag power on coast down when dipping the clutch, and adding this to the wheel power to return a calculated figure for flywheel power.

2. The power I measured was at the wheels, taken at constant rpm during a static test. Transmission loss was not measured, nor was it required, therefore power at the flywheel was not given.

3. The power reading itself was merely recorded as a matter of interested for this experiment. Perhaps I should not have even bothered posting it as it has simply added to confusion. The measurements I was most interested in was boost.

4. VADIS only measures 3 parameters simultaneously for diagnostics purposes, therefore providing the 4 parameters as you request is not actually possible with VADIS alone.

5. There is no legal requirement for a dyno calibration certificate, as is required for an MOT brake roller. Most dynos are calibrated in house for the purpose of accuracy.

6. Intake temps were not the only clue to lack of cooling. The fact that the engine coolant temp was climbing way above normal, as mentioned earlier, was a big clue!

Adam.

>>Rooster, it was 250 bhp @ THE WHEELS @ 6000 rpm when down
>by
>>0.2 bar.
>>
>>Adam.
>Hi Adam how exactly did you calculate the above quoted figure
>? I have read a thread from yourself minutes ago on another
>volvo forum which clearly explains that any rolling road tests
>caried out with the engine in a car cannot give accurate at
>the wheels bhp figures due to unknown transmission loss and
>also refers to guess work over these figures.Is this your
>guesswork or are you prepared to offer the dyno printout for
>the said car or any car you chip for that matter so that some
>more accurate figures can be obtained. Also please supply all
>management parameters at said power readings, you have vadis
>so these can be provided, ie intake air temp, maf voltage,
>injector times, boost pressure etc etc. As you should know
>these details will provide the information to tell infact
>weather or not there was a poor inlet air temp at the rolling
>road or not. The thread i refer to can be found here.
>
>
>http://volvo-t5.co.uk/phpbb/viewtopi...autos&start=15
>
>Once all the above details have been provided on the forum
>anyone will be able to comment on your statements and
>hopefully attempt to substantiate your statements regarding
>rica chipping and true bhp readings.
>
>ps a copy of the dyno calibration certificate will need
>posting up.
>
>I await your response eagerly
>
>thanks stuart

Thanks Bob!

Adam.

>The accepted way of emphasising a word/words without using
>capital letters is to put an asterisk either side, like so:
>*hello*.
>
>Bob
>_____________________________
>Robert Isaac
>Volvo Owners Club
>Director and Web Admin

[Ross9]

No offence meant, in the time old tradition, but come on, picking up on capitals? It's like a schooglround, I found Adams info quite interesting

You will never get a real world reading on a Dyno, no matter how hard you try to emulate, but it was interesting to see it go the other way then we are used to up north.

3 main Dyno's seem to have emerged, AVA run @ wheels only. steady state, measured at 500rpm intervals, very hard on the car and are notorious for giving unforgiving tranny losses, ie if you hit 190 @ wheels in a fwd they will tell you your car is at most 210 @ fly, 20 bhp loss, even though a standard version of my car is 160 @ wheels and 197 @ fly.

Star performance and Dastek do free running dynos, or should I say, one sweep, 1000rpm to limiter and then measure the tranny losses on coastdown, which i believe gives a much more accurate figure for real world use, though star performance always show absolute crap @ wheels figures and HUGE transmission losses. As Stansard my car is supposed to run 14.9 1/4's and make 197 bhp @ fly, 165 @ wheels, on its last spec before going off road for serious tuning I ran a 14.2 @ 102 which star claimed at 235 @ fly with 165 @ wheels,which lets face it is bull**** for a 2wd, 70 bhp loss, my arse. AVA ran the car a week later at the same spec, and got 190 @ wheels, and esrt 210 @ fly.

The long and short of it is, that Dynos are there for tuning and fun RR days, if ypou really want to prove your car, stop fannying around and saying this saying that, and get the thing on a track/drag strip. I've yet to see a disapointed RICA owner post, bhp figs or not, but I've still to see a RICA owner get near my 14.2 @ 101 in Jacqs VOlvo as well, which funniliy enough, was done in reality, on a timed drag strip, in real world conditions.... ;), while being 1 cylinder and 0.3-0.4 litres down as well :p

Ross

[Simon Linton]

Just another syntactical point Adam, when you put quote marks round a word which is not a quotation, you are calling its veracity into question - I'm a VOC official, not an "official".

And BTW, I was trying to cool down a thread that was heading for meltdown and confirming other members' points about the necessity for decent cooling on dynos and the *practical* application of tuning upgrades wherever sourced; not calling into question your initial figures.

Since I have not installed either the TME or the RICA upgrade I cannot and will not comment on their respective benefits - I can only pass the views of those who have done so.

[Simon Linton]

Ummm - "...pass on the views of those..."

That's better!