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I've noticed on a high percentage of dyno charts posted here that the graph/numbers for TQ at around 2000 to just under 3000 are flat and vary a lot until 3000 then they climb and this seems to be high percentage with varied performance options and engine size. Being a high percentage why do they do this?

This is my chart.


This is a chart PJrom posted (great numbers)

Half crazy

PJrom again

pimtout

See the pattern again not all but they all have a common theme.
 

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The dyno operator snaps the throttle open at around 2000 rpm... the intake air velocity drops to nothing then the engine recovers.
Sometimes the dip you see is a function of the exhaust system, sometimes the cams, or it could be too large a throttle body for the engine's displacement.
The Thor pipe has that dip after the initial hit... the Slash pipes were flat to 3200...
 

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The dyno operator snaps the throttle open at around 2000 rpm... the intake air velocity drops to nothing then the engine recovers.
Sometimes the dip you see is a function of the exhaust system, sometimes the cams, or it could be too large a throttle body for the engine's displacement.
The Thor pipe has that dip after the initial hit... the Slash pipes were flat to 3200...
That makes sense because mine is basically stock and yours is modified and they both do it in the same spot.
 

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Yes another question these are from two different dynos one 0 smoothing the other a 5 smoothing both SAE. Why is the one so extremely jagged and the other is relatively straight? No reason except curious.

Cool thing about having the run files is being able to compare one to another then I started messing with the smoothing and noticed a big difference.

Zero smoothing



Five smoothing
 

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my torque is up over 100 from right from the start, don't have that initial falter.
Perfect match of parts combined with smaller displacement maybe?
I lose out in the top end though over 106s and cammed 106s
 

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Does this graph make my torque look too fat?

Actually it looks like these Lil cams keep my torque pretty steady after 3k rpm. I know the bike seems to pull forever but the problem is I run out of road before I can realize the true power. I ride at 2300 to 2800 rpm always and when I find the space to roll on hard the power really comes on after 3200rpm. to hit 110 mph on this bike comes fast. Very impressive for a small price.
 

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Look at the red line on my first chart from post #4 how erratic it is without smoothing but the other line is basically unaffected.

Sorry to be clear I asked another question different from the first.
 

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Temps and humidity have a significant role in how the dyno tune ends up. When I took my bike to Rylan to get the cams and vfc3 installed you could almost cut the air it was so humid. only change between his dyno and this last one was the change to a PCV and the considerably lower temp & humidity. Gained 19hp and 18 lb.ft. of torque changing to the PCV.



 

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Look at the red line on my first chart from post #4 how erratic it is without smoothing but the other line is basically unaffected.

Sorry to be clear I asked another question different from the first.
Smoothing is just that. It smooths out the values that are displayed. You could think of the other chart as raw data. If you want to understand what your engine is doing, it helps to smooth out the graph so that you can tell when things happen and what changes might help. I bet your tuner is using the smoothed data to tweak in your fuel controller because it tells him/her what is really happening in that engine.
 

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Temps and humidity have a significant role in how the dyno tune ends up. When I took my bike to Rylan to get the cams and vfc3 installed you could almost cut the air it was so humid. only change between his dyno and this last one was the change to a PCV and the considerably lower temp & humidity. Gained 19hp and 18 lb.ft. of torque changing to the PCV.








That's interesting. Though I do bet you also you gained by the tuner change. Not to get on that topic but you've got a more accurate dialed in tune now.

When I dyno'd it was after a hot air downpour and you could see the steam and still drizzling. Dunno what 112 and 112 should feel like but she pulls like a beast. I had read that the whole day the numbers were on the low side.


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Discussion Starter #13
Smoothing is just that. It smooths out the values that are displayed. You could think of the other chart as raw data. If you want to understand what your engine is doing, it helps to smooth out the graph so that you can tell when things happen and what changes might help. I bet your tuner is using the smoothed data to tweak in your fuel controller because it tells him/her what is really happening in that engine.
True just wierd on is fairly smooth and the other isn't when set to zero smoothing.
 

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cold air can give me almost a second over the quarter mile in my car,
though track temps need to be taken into account too.
Bit hesitant to run the bike as in stressing the belt unduly,
and the high probability of another addiction, and consequent fitting of cams etc.
Got a sweet running bike, I'm heading out to pick up a pretty girl and take her riding.:)
 

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True just wierd on is fairly smooth and the other isn't when set to zero smoothing.
mine smoothed itself out considerably with Torque Tubes the only difference.
Steve, the Dynoman specifically pointed that out, though I think the Ness, or indeed a Lloyds or S&S filter may suck in more air at Wide Open Throttle...marginal though.
I reckon cubes and cams and TTI vs cubes cams and S&S etc. would be close at WOT, and TTI better down low.
Im off for a ride anyway:)
 

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