bhvrdr

look where your first response to me is Dave. It is under my post where you stated it was inaccurate/loaded. You have then gone on to state all of your blub blub about how chassis dynos are all completely inacurate. You have been proven incorrect on this Dave. In fact in all of these posts back and forth you have provided NOT a SINGLE piece of FACT from any third party source supporting your claim. Yet you have seen now that SAE journals show dyno testing is accepted and OEM Audi and Porsche accept chassis testing and have provided white papers.

Cars vary from dyno to dyno. We all know that. That is because parasitics vary from dyno to dyno and IF you are interested in chp to whp conversion then you could measure that and it will correct for it on each dyno. If on the other hand you are intersted in whp to whp and testing DIFFERENCES (like most of us here are) then you can test that too and there is no need for parasitic loss testing. EIther way you want to go. And yes Dave, cars can even show different whp numbers in the same state of tune on the same dyno. The differences are minimal of course and they are expected. Guess what Dave, cars put down different power across different conditions. YOur car will put down different hp on the road in the summer than in the winter. Your dynometer can measure this. That is accuracy Dave. FOr example, you can therefore measure how advanced cooling techniques affect power delivery to the wheels.

daveak05

and stop putting words in my mouth.

anybody who bandies about a specific HP number for their RS4 based on a chassis dyno, modded or not, is putting out worthless information. and we see it here all the time.

and you keep flip-flopping on this subject too. on the one hand you agree that there are many variables that affect the outcome, and that they can be manipulated, AND on the other hand you defend chassis dyno results to the hilt...always with your own customized proviso that one must calculate for losses and apply a margin of error. GAWD, LOL! Please get off your pedestal and open your eyes.

bhvrdr

poorly presented or poorly run results. For example some one who JUST posts a single dyno run and then attempts to derive something from it based on other peoples runs. But posting your controlled condition before and after runs is not worthless at all. It is very helpful for people to see and for yourself to see if parts are having an effect, to assist in diagnosing problems, etc.

RI A6

I don't see any of the results as worthless, especially when they are relative measurements. But I do want to know how they were taken, what the conditions were. The rest can be figured out.

RI A6

"and you keep flip-flopping on this subject too. on the one hand you agree that there are many variables that affect the outcome, and that they can be manipulated,AND on the other hand you defend chassis dyno results to the hilt"

This is not a flip-flop it is perfectly consistent. There are lots of variables in everything that is measured in this world. And results are manipulated all the time. I agree. But that is entirely different than the accuracy or validity of a particular measurement instrument. A chassis dyno measures what it is supposed to measure: torque as delivered to the road.

These are separate issues:

1) Can a chassis dyno make and accurate measurement of torque delivered to the road? Yes.

2) Can the measurement be so uncontrolled as to totally invalidate the results? Yes.

3) Can the measurement be manipulated? Yes.


But 2 and 3 can apply to anything. So what?

s4wood

Hi Mike!

bhvrdr

I suppose she should be. AW can always use a bit more traffic right

Hi Steve

daveak05

i'm about to have several, based on this discussion : )

RI A6

Cheers!

daveak05

for doing this again.