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Why id the Honda F1 car noisier than all the others?


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#1 mariner

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Posted 26 May 2008 - 14:35

Last week I finally got to see F1 cars run at Monaco. The price of tickets and hotels over raceday made that unaffordable for family of four but Thursday was only 70 Euro for four hours of F1 practice (and it was dry).

I would have to say that surreal though Monaco is as a place they do a very class act of putting F1 onto their streets and letting you get so close to the cars, looking at he cars coming head-on into the swimming pool copmlex gives a whloe new meaning to turn-in.

However my question is about the noise levels of the cars, the Honda's were clearly louder than any other engine. As all the engines run at the 19,000 rpm limit and are V-8's with, I assume, flat plane cranks and a 90 degree V why the decibel differnce? Is it just due to exhaust outlet placement and does it indicate more ( or less ) power?

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#2 naiboz

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Posted 26 May 2008 - 19:16

No idea

But my memory from Monza 06 was that the Honda's were far the sweetest sounding engines, they absolutely screamed, followed closely by the bmw's.

I was amazed at how different the engines sounded compared the tv.

#3 TDIMeister

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Posted 26 May 2008 - 20:12

Probably Honda's choice of firing order (I don't know what it is).

#4 Beedeeai

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Posted 26 May 2008 - 20:18

Less sponsors stickers on the bodywork to muffle the engine sound ;)

#5 Catalina Park

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Posted 27 May 2008 - 11:19

Probably wasting more power out the exhaust than the others.

#6 rookie

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Posted 27 May 2008 - 17:24

Originally posted by TDIMeister
Probably Honda's choice of firing order (I don't know what it is).


2nd that. If you have heard the Ducatis in Moto GP, they sound like a totally different engine from the rest even though all the same spec.

Firing order plays a big part.


#7 desmo

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Posted 27 May 2008 - 17:48

Isn't the sound energy of the exhaust just a symptom of inefficiency? I mean every dB out the tailpipe surely represents energy not available as tractive force. I'd expect an ideally efficient IC engine to be relatively quiet even if not fitted with mufflers. In practice the energy loss is probably insignificant overall, but imagine the wattage it'd take to reproduce the sound energy levels of an F1 engine in full song through electronic amplification and speakers.

#8 Engineguy

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Posted 27 May 2008 - 21:39

I think they make the same sound... they're just going so much slower that the doppler effect is altered relative to the other cars. :clap: (kick 'em while they're down :blush: )

Pop vs. woosh:
Seriously, it would most likely be in the cam profile... but it's not necessarilly bad... they may be getting a stronger pulse over a shorter time, opening exhaust valve later but faster, for example. The sound level instantaneous peak could be higher even if it's the same or less averaged over time.

#9 hydra

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Posted 27 May 2008 - 22:00

Originally posted by Engineguy
I think they make the same sound... they're just going so much slower that the doppler effect is altered relative to the other cars. :clap: (kick 'em while they're down :blush: )

Pop vs. woosh:
Seriously, it would most likely be in the cam profile... but it's not necessarilly bad... they may be getting a stronger pulse over a shorter time, opening exhaust valve later but faster, for example. The sound level instantaneous peak could be higher even if it's the same or less averaged over time.



OT, but you have PM Engineguy..

#10 Timstr11

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Posted 28 May 2008 - 06:42

Originally posted by mariner
Last week I finally got to see F1 cars run at Monaco. The price of tickets and hotels over raceday made that unaffordable for family of four but Thursday was only 70 Euro for four hours of F1 practice (and it was dry).

I would have to say that surreal though Monaco is as a place they do a very class act of putting F1 onto their streets and letting you get so close to the cars, looking at he cars coming head-on into the swimming pool copmlex gives a whloe new meaning to turn-in.

However my question is about the noise levels of the cars, the Honda's were clearly louder than any other engine. As all the engines run at the 19,000 rpm limit and are V-8's with, I assume, flat plane cranks and a 90 degree V why the decibel differnce? Is it just due to exhaust outlet placement and does it indicate more ( or less ) power?

Interesting.
I experienced the same when I visited the Barcelona GP a few weeks ago.
The Hondas and Super Aguris were indeed significantly louder than other engines.

#11 TDIMeister

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Posted 28 May 2008 - 07:02

Firing order will affect exhaust gas flow and thus peaks in different engine harmonic orders and also different frequencies. The human ear does not perceive equal loudness at each frequency, but is most sensitive at around 1kHz and drops off at increasing and decreasing frequencies. The human ear also perceives different harmonics differently when it is superpositioned on other harmonics or against background noise.

There are 3 main parameters that define engine-generated sound: harmonic order, frequency and sound pressure level. A doubling of SPL only amounts to 6 dB. Point is, qualitative expression of loudness can be influenced by other factors than SPL itself, meaning one might perceive a very different degree of loudness, but a sound meter may show objectively not to be the case.

I don't buy the argument that one engine is louder because it is less efficient at least in an F1 context. Race cars of the league of F1 are pushing right at the limits of technology, and in particular the engines from different suppliers are developed to a very high and, I would argue, uniform level of technology as permitted by the rules, performance and efficiency. There are no obvious tricks based on the current state-of-the-art that would not have been already exploited by all teams.

BTW, I got to meet a friend-of-a-friend last weekend in Munich working at BMW F1, currently on assignment at Sauber in Switzerland doing gearbox development.

#12 Ross Stonefeld

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Posted 28 May 2008 - 15:34

Originally posted by rookie


2nd that. If you have heard the Ducatis in Moto GP, they sound like a totally different engine from the rest even though all the same spec.

Firing order plays a big part.


Spec maybe, design no.

#13 DOHC

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Posted 29 May 2008 - 06:47

Originally posted by desmo
Isn't the sound energy of the exhaust just a symptom of inefficiency? I mean every dB out the tailpipe surely represents energy not available as tractive force. I'd expect an ideally efficient IC engine to be relatively quiet even if not fitted with mufflers. In practice the energy loss is probably insignificant overall, but imagine the wattage it'd take to reproduce the sound energy levels of an F1 engine in full song through electronic amplification and speakers.


Sound generally has very low power. The wattage you need to reproduce sound is astronomical, because it is typically all wasted in heat in the speaker; dynamic loudspeakers have very low efficiency.

0 dB sound pressure level (SPL) corresponds to an output of 1 pW at 1 m distance. It is often called 0 dBp, with the lower case "p" indicating the reference level of 1 pW. One picowatt is 1e-12 Watts, and unimaginably small power. 100 dBp SPL corresponds to 0.01 W; 120 dBp (now we're talking serious noise!) is one full Watt of acoustic power!

An "efficient" dynamic speaker might produce 90 dBp for 1 W of electric power input. As 90 dBp is only 0.001 W acoustic power, the efficiency of the speaker is 0.001, i.e., it wastes 99.9% of the electric power in heat and produces only the last 0.1% in sound energy. Even so, 90 dBp is fairly loud in your living room, and one shouldn't be surprised if wifey asks you to turn down the volume a little bit.

An efficiency of 0.001 is equivalent to -30 dB (no p this time, as "dB" is just a ratio).

Now check your amplifier. Perhaps it boasts 2x100 W electric output. That's 2x 1e14 pW, or in terms of dB, 2x140 dBp.

This means your amp can crank out 140 dBp (electric power) - 30 dB (losses in speaker) = max 110 dBp SPL per channel, if you run the volume control wide open.

That's going to be very loud. Yet it's only 0.1 W SPL that ends up in your sofa. Per channel of course, implying that in fact it might be as much as 0.2 W at the end of the day. Still it's minute.

So the noise generated by an F1 car is much louder? Sure, maybe 140 dBp ? That's a whole 100 whopping Watts. Per channel, of course, since a V8 usually runs in stereo...;)

Anyway, the conclusion is that the noise level is completely insignificant as a measure of losses. Maybe the engine's mechanical output is 500 kW, with thermal losses exceeding 1 MW. That surely dwarfs the 100 W acoustic output by some four orders of magnitude. And even if the Honda is 10 dB louder than everybody else, the acoustic loss in only on the order of a few hundred Watts. Hardly more than half a horsepower. :smoking:

In general, acoustic losses are less than 0.1%. Not a worry in a thermodynamic machine, which easily loses 70% to heat anyway.

#14 Greg Locock

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Posted 29 May 2008 - 10:26

Thanks DOHC. I tried to work it out sensibly, but it all got a bit nerdy. Your explanation is at least comprehensible.

#15 rookie

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Posted 30 May 2008 - 10:19

Originally posted by Ross Stonefeld


Spec maybe, design no.


tamata, tomato. I think we both mean the same thing.

#16 Rosemayer

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Posted 30 May 2008 - 12:54

Originally posted by rookie


tamata, tomato. I think we both mean the same thing.


New specifications for each racing class are formed as the FIM sees fit. At the beginning of the new MotoGP era in 2002, 500 cc two-stroke or 990 cc four-stroke bikes were specified to race. The enormous power advantage of the larger displacement four-stroke engine over the two-stroke eliminated all two-strokes from competition; the following season no two-stroke bikes were racing. In 2007 the maximum engine capacity was reduced to 800 cc without reducing the existing weight restrictions.

MotoGP-class motorcycles are not restricted to any specific engine configuration. However the number of cylinders employed in the engine determines the motorcycle's permitted minimum weight; more cylinders attracting more weight as a form of handicap. This is necessary because, for a given capacity, an engine with more cylinders is capable of producing more power. If comparable bore to stroke ratios are employed an engine with more cylinders will have a greater piston area and a shorter stroke. The increased piston area permits an increase in the total valve area, allowing more air and fuel to be drawn into the engine, and the shorter stroke permits higher revs at the same piston speed, allowing the engine to pump still more air and fuel with the potential to produce more power but with more fuel consumption too. In 2004 motorcycles were entered with three-, four-and five-cylinder configurations. A six-cylinder engine was proposed by Blata, but did not reach the MotoGP grids. Presently four cylinder engines appear to offer the best compromise between weight, power and fuel consumption as all competitors in the 2008 series use this solution in either vee or in-line configuration.

In 2002, the FIM become concerned at the advances in design and engineering that resulted in higher speeds around the race track. For purposes of increasing safety, regulation changes related to weight, amount of available fuel and engine capacity were introduced. The amended rules reduced engine capacity to 800 cc from 990 cc and restricted the amount of available fuel for race distance from 26 litres in year 2004 to 21 litres in year 2007 and onwards. In addition, the minimum weight of 4 cylinder bike used by all participating teams was increased by 3 kg.

Although the changes in specifications were intended to reduce both average and maximum speeds, their effect can be questioned. While the MotoGP speed record of 347.4 km/h (215.864 mph) for 990 cc bikes is held by Loris Capirossi on a Ducati Desmosedici GP4 at IRTA Tests in Catalunya in 2004, the current speed record for a 800 cc bike is held by Casey Stoner on a Ducati Desmosedici GP8 and set at Grand Prix of China 2008 race at 343.2km/h (213.25 mph).[3] While comparing top speeds, it is worth noting that the 800 cc speed record is set with a bike in race trim, while the 990 cc record is set on a test. In addition, when lap times for 990 cc and 800 cc bikes are compared, the 800 cc bikes are typically faster around race tracks than the 990 cc bikes. As the top speeds of 990 cc are slightly faster than with the 800 cc, the difference can be explained by higher corner speeds of 800 cc bikes.

By way of comparison, the current Formula One speed record of 369.9 km/h (229.8 mph) was set by Antônio Pizzonia of the BMW Williams F1 team, at Monza in 2004 -- however, top speed is only a small portion of the overall capabilities of any track vehicle and thus does not represent the difference between Formula One and MotoGP performance-wise in general.

#17 desmo

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Posted 30 May 2008 - 23:46

Thanks DOHC. I should have remembered that even with inefficient speakers and 500 watts RMS,the speaker wires seem to carry a pretty small electrical load. I can hook up a couple of tiny copper filaments from their outboard ends only and get plenty of volume. And I can do it bare handed with the wire hot.

#18 Modulus

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Posted 01 June 2008 - 02:31

A few years ago at a Silverstone test session, it seemed very obvious to me that the BMWs were very loud, compared to most the other cars. I haven't heard the current cars, though I hope to be at Silverstone for the Pre-GP test in a few weeks.

Mercedes were getting some bad press in Germany when the V8s were first testing, because their engine sounded 'rougher' than the others and it was giving people the impression that it wasn't such a precisely engineered, delicate work of art/engineering. I think it was put down to uneven primary lengths, but thats a bit of speculation combined with a bad memory on my part.

#19 alexbiker

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Posted 02 June 2008 - 13:20

Originally posted by Rosemayer
[B

Although the changes in specifications were intended to reduce both average and maximum speeds, their effect can be questioned. While the MotoGP speed record of 347.4 km/h (215.864 mph) for 990 cc bikes is held by Loris Capirossi on a Ducati Desmosedici GP4 at IRTA Tests in Catalunya in 2004, the current speed record for a 800 cc bike is held by Casey Stoner on a Ducati Desmosedici GP8 and set at Grand Prix of China 2008 race at 343.2km/h (213.25 mph).[3] While comparing top speeds, it is worth noting that the 800 cc speed record is set with a bike in race trim, while the 990 cc record is set on a test. In addition, when lap times for 990 cc and 800 cc bikes are compared, the 800 cc bikes are typically faster around race tracks than the 990 cc bikes. As the top speeds of 990 cc are slightly faster than with the 800 cc, the difference can be explained by higher corner speeds of 800 cc bikes.
[/B]


I would also note that this kyboshes the saftey argument completely. It was always known that the teams were tuning down the 990cc engines away from peak power - by electronics and by paired or long-bang firing orders - in order to tame them, and the riders were squaring off bends in order to get on the power as soon as possible. This killed the corner speeds, and the combination of virtually limitless power and TC had by-and-large eliminated the highside from the repertoire of crashes.

It was obvious that the teams would tune the 800s back up to get the power back, and the lower torque of the new engines reduced the need to square-off bends, and gave a more friendly power delivery - so the corner speeds went back up, and up, and the safety argument goes out of the window - because people do tend to crash on the corners, and rarely on the straights.

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#20 primer

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Posted 06 June 2008 - 10:55

The corner speeds would have increased to current levels with 990s even.
If the idea is to limit corner speeds, get control / single-supplier tires.

#21 alexbiker

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Posted 06 June 2008 - 13:44

No - the tyre manufacturers have changed their designs to enhance corner speed specifically for the 800s, which is why they're faster. The old 990's had so much grunt there was more time to be made standing the bike up early and firing it off down the straight, at the expense of apex speed. We're not talking subtle differences here - the 800s are massively faster at the apex.