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Kropotkin said:
Great work that man! About right. Nice, conservative Honda engineering. And so far inside the performance envelope that Honda might even be running at less than the maximum bore, going for torque instead of HP. they've done that in Moto3.
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No worries!



Color me skeptical regarding the downsized bore. Wide pistons generally = room for bigger valves = more power across the entire rev band.



Please define 'torque.' Do you mean midrange power (the shape of the power curve), or absolute crankshaft torque output (94 foot-pounds, or whatever they're making.)
 
I'm getting only 14.7K for the Yamaha. Probably not a screaming hot lap!



It has an unusual signature, producing a strong pulse once every 4 crank revolutions. No doubt due to exhaust pulses bouncing around in the headers.
 
Geonerd said:
No worries!



Color me skeptical regarding the downsized bore. Wide pistons generally = room for bigger valves = more power across the entire rev band.



Please define 'torque.' Do you mean midrange power (the shape of the power curve), or absolute crankshaft torque output (94 foot-pounds, or whatever they're making.)
Click to expand...



Actually, want I mean is a nice fat powerband. These things could easily make 300hp, but you can't use that power. 255 with a nice wide spread is much, much better.
 
Geonerd said:
The Duc was a hard one to interpret. The individual pulses vary quite a lot in amplitude. The best 'tell' I could find was the ascending 'staircase' feature.



I'll go back and watch the Eurosport qualifying vid, in search of on-board sounds during a proper hot-lap.
Click to expand...



The big bang config makes it hard. Taking a margin of error, 17250 would put the Ducati right about 16750, which is 27 m/s piston speed, which is what we would expect with a 1000cc engine pushed to the limits. It would also explain Rossi's annoyance at the "lion under the fairing" aggressive power delivery.
 
Geonerd said:
Honda: from 2:08, right before he shifts.



325 samples at 44,000 per second

= .00739 ms

= 135 bangs per second

= 8100 bangs per minute

= 16,200 RPM.





13467:Honda.jpg]
Click to expand...



On the Honda ,Cool! well done Geo. I have not even had a chance to convert the vids yet but I did put a hand held frequency meter on the sound out and got around 16,000. Small/short sample and a dicky reading of around 134hz ....... which equates to 16,080 .....



The Ducati was difficult to measure by this method, as its readout varied so much, would not have settled on a definite reading for the Duc. Reading fluctuated between 137 to 147 hz. Its no 19,000 though.
 
Kropotkin said:
Great work that man! About right. Nice, conservative Honda engineering. And so far inside the performance envelope that Honda might even be running at less than the maximum bore, going for torque instead of HP. they've done that in Moto3.
Click to expand...



Moto3 is rev-limited. 81mm bore isn't necessary to achieve the rev ceiling and 250cc engines probably need the extra torque. Reducing the bore size in MotoGP would cost tens of horsepower and restrict the breathing capabilities of the engine. The surplus torque would be superfluous, imo.



16,200rpm is almost exactly 26m/s average piston velocity for an 81mm bike at WOT. Sounds right. The Yamaha number is surely too low, unless the rider was "trundling" around. For Yamaha to be down that much on power would be an embarrassment. Duc number seems too high, but who knows.
 
I've run the Duc several times and keep getting the same values. Here's a slightly different section of the waveform after running a low-pass. This cleans up the jaggies and makes the periodic signal easier to see. Unless I'm having a blonde moment with the math, 17,100~17,200 RPM is correct.



13469:Ducati2.jpg]



I'll look for more Yamaha noises, and really want to see what the Kwacker, BMW and Aprillia are turning.





Edit - found one Ducati sample at 17,350 (!) This was averaged over three waveform cycles, so is likely to be fairly accurate.
 

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If anyone want to play with this, you can download a demo of Cool Edit Pro that should (?) be able to discern peak-to-peak timings as seen above. http://www.softpedia...-Edit-Pro.shtml



Open source Audacity might also do the trick. http://sourceforge.net/projects/audacity/?source=directory



If it works the same as my Cool Edit 2000, click on the horizontal scale, just below the black area, to select the time-base units. Switch from seconds (which don't show enough resolution) to samples and you're good.
 
Geonerd said:
I've run the Duc several times and keep getting the same values. Here's a slightly different section of the waveform after running a low-pass. This cleans up the jaggies and makes the periodic signal easier to see. Unless I'm having a blonde moment with the math, 17,100~17,200 RPM is correct.



13469:Ducati2.jpg]



I'll look for more Yamaha noises, and really want to see what the Kwacker, BMW and Aprillia are turning.





Edit - found one Ducati sample at 17,350 (!) This was averaged over three waveform cycles, so is likely to be fairly accurate.
Click to expand...



All samples are definitely WOT, not overrun? If the rev ceiling is 17,100rpm-17,300rpm, the bike probably is 930cc. The numbers would line up perfectly.
 
[media]http://www.youtube.com/watch?v=rmwOPFmJ8vw[/media]



~11 seconds into the video, right before he changes up to the last gear.

I got 17,266 RPM, averaged over 6 periods, during which time the engine is still gaining revs.

If this isn't WOT, I don't know what is.



I did find a blonde goof, I was using 44,000 Hz as the sample rate, it's actually 44,100. This increases the calculated RPM.
 

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New record for the Duc.

Using the software's automagic analysis, it picks up the dominant frequency of 145.95 Hz. at the very end of the straight.

(Manual calculations agree within 10 RPM (+/- a sample or two.)



This gives 17560 RPM (!)





13473:Duc_Record.jpg]
 

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Watching Eurosport Qatar Qual. Grabbing samples of any on-board camera audio at highest revs.



So far, max RPMs are...



Bradl - 15780, 16150

Bautista - 16020, 15900

Spies on hot lap - 16300, 16350, 15750

Crutchlow 15750

Peddles 15600, 16200, 15900

Bradl, last lap. 16280
 
Never used that cool edit before ........ its pretty good.



Gives C#3 for that Ducati clip you have .......... has midi convert too I think ........ so we could convert it so the Bike sounds like a piano going around!!
<
<




Whats that voice correction thing that Cher used? that may be fun!
 
Geonerd said:
New record for the Duc.

Using the software's automagic analysis, it picks up the dominant frequency of 145.95 Hz. at the very end of the straight.

(Manual calculations agree within 10 RPM (+/- a sample or two.)



This gives 17560 RPM (!)





13473:Duc_Record.jpg]
Click to expand...



Kropo

Next time it could be better to record it at a higher sample and bit rate 96k 24 bit for this type of analysis, a zoom H4n handy recorder is quite cheap and easy to use and records HD audio. You could also plug a couple of Super/Hyper cardioid shot gun mics into this recorder, record the channels in isolation and spread the mics for capturing entry and exit for a broader look across both seperate

waveforms. These mics will aid in reducing unwanted bounce. Speak to the audio boys in the ob truck they could probably lend you a couple of these mics/cables.....



I'll check out your waveforms myself in Protools as well
 
BarryMachine said:
Whats that voice correction thing that Cher used? that may be fun!
Click to expand...



That is a VST plugin called Antares Autotune.



Cool Edit Pro was purchased by Adobe and is now being called Audition/Soundbooth and is part of the Creative Studio suite....I have always been a Sound Forge fan myself but CEP was equally good software and had multitrack capabilities which made it a good audio mastering option.
 
Talpa said:
Kropo

Next time it could be better to record it at a higher sample and bit rate 96k 24 bit for this type of analysis, a zoom H4n handy recorder is quite cheap and easy to use and records HD audio. You could also plug a couple of Super/Hyper cardioid shot gun mics into this recorder, record the channels in isolation and spread the mics for capturing entry and exit for a broader look across both seperate

waveforms. These mics will aid in reducing unwanted bounce. Speak to the audio boys in the ob truck they could probably lend you a couple of these mics/cables.....



I'll check out your waveforms myself in Protools as well
Click to expand...



I really think this is always going to be a problem, and hardly worth even bothering.. The lucky thing is Dorna have good recordings well filtered and presentable available on those onboard vid's. Dorna are good for something after all
<
<




As you can see with the wave forms the sample rate is fine, Haven't seen one cropped or lost peak or trough.



The other problem is you minimize your sample and it is never really stable due to, as Stiefel suggested ......... the Doppler effect. With two mikes you are even worse off. Hence the suggestion for getting onboard samples ........ plus they tend to be just bike and wind noises trafck feature reflections are minimized ( then filtered by Dorna )
 
BarryMachine said:
I really think this is always going to be a problem, and hardly worth even bothering.. The lucky thing is Dorna have good recordings well filtered and presentable available on those onboard vid's. Dorna are good for something after all
<
<




As you can see with the wave forms the sample rate is fine, Haven't seen one cropped or lost peak or trough.



The other problem is you minimize your sample and it is never really stable due to, as Stiefel suggested ......... the Doppler effect. With two mikes you are even worse off. Hence the suggestion for getting onboard samples ........ plus they tend to be just bike and wind noises trafck feature reflections are minimized ( then filtered by Dorna )
Click to expand...



That on board audio is quite compressed and normally the camera pres are using auto gain with low quality mics-not ideal when searching for this type of analysis with the variables that exist when trying to record sound at this amplitude.



I'm well aware of the Doppler effect, that's why I suggested the mics to be recorded in isolation across two channels- giving options, not analyzing the stereo result but the differing mono recordings from both angles- with the use of hyper/super cardioid shotguns offers a better chance to minimize unwanted noise.
 
Talpa said:
That on board audio is quite compressed and normally the camera pres are using auto gain with low quality mics-not ideal when searching for this type of analysis with the variables that exist when trying to record sound at this amplitude.



I'm well aware of the Doppler effect, that's why I suggested the mics to be recorded in isolation across two channels- giving options, not analyzing the stereo result but the differing mono recordings from both angles- with the use of hyper/super cardioid shotguns offers a better chance to minimize unwanted noise.
Click to expand...



Even worse ...... its a problem with one.



The onboard is better filtered than anybody but those who do it professionally do. I believe these techo's would know what they are doing. Anybody else would just be reinventing the wheel and likely after a learning period finally getting to the point these guys are at now. I'm actually quite impressed they get the sound as good as they do. The fact that we can read the data ( and as you can see jobs done .... Geo has done wonders ) , more than adequately for the purpose, is testament to their skill.
 

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