This could definately be true. I'm just explaining what will happen to back pressure if you decrease the piping diameter (it will rise).

As for what the optimum back pressure for an engine is, I don't think many people could tell you what and why, there are just so many factors in play when it comes to internal combustion engine power. It would definately be a trial an error process. We do know that too much or too little can have a detrimental effect...

Let me see the currrrrves baby!

Yes, obviously uping the sample rate will give more data points, and therefore a more accurate graph.

I'm still not sure how someone can look at a graph and go "ohh, thats just lumpy because of an increased sample frequency (No. of data points)", because, as you say, the markings on an axis are just guides and don't affect the amount of data in a graph (the sample frequency does.)

It was interesting to read of the benefits of the hub dyno though, and why it has the ability to produce more accurate plots than roller dynos, though as you say, you don't feel this on the road due to the inertia of the wheels and the car itself.

Anyway, I'm sure you and everyone else has had enough of this already, so I won't go any further.

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John Stamos fan club lifetime member

basically, all car's results will be 'shakey' with sufficent samples.

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Long live the WRC

Fair enough.

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John Stamos fan club lifetime member