Honda Power Unit Hardware & Software

[rscsr]

Big bang engines in motogp have been introduced to have more rear wheel grip and for having a softer caracter of power delivery.
By unequalising the fire order of the engine, there comes a frequency change of power delivered to the tyre.
Think of the tire gets some more time to rest after 2 rapid combustions.

I pretty much doubt that the "leave the tyre some rest" theory is right.
This is my explanation without any sources.
Rubber behaves visco-elasticaly. At higher frequency the storage modulus (which essentially describes the elastic behaviour, basically you get the energy back) becomes bigger in relation to the loss modulus (which essentially describes the inelastic behaviour, basically what you lose). This means that you want to use an engine with a higher frequency --> a big bang engine produces oscillations at a higher frequency than a screamer is during the power stroke. This means imho less slip angle for a big bang engine.

[PlatinumZealot]

What type of frequencies are you talking about though?
I imagine a big vang engine would have higher amplitude of vibration but lower frequncy if you look at the torque output.. Unless ypu are talking about some other frequency?

[rscsr]

What type of frequencies are you talking about though?
I imagine a big vang engine would have higher amplitude of vibration but lower frequncy if you look at the torque output.. Unless ypu are talking about some other frequency?

basically my thinking is an even firing (4 cylinder) engine has torque pulses every 180°. A big bang could have one every 90° (and then no pulses). Basically it fires at twice the frequency when it fires.
So in essence, I think the tyre is becoming stiffer when the engine fires and when it doesn't fire you don't need the additional stiffnes anyway.
At least I imagine it that way.

[PlatinumZealot]

What type of frequencies are you talking about though?
I imagine a big vang engine would have higher amplitude of vibration but lower frequncy if you look at the torque output.. Unless ypu are talking about some other frequency?

basically my thinking is an even firing (4 cylinder) engine has torque pulses every 180°. A big bang could have one every 90° (and then no pulses). Basically it fires at twice the frequency when it fires.
So in essence, I think the tyre is becoming stiffer when the engine fires and when it doesn't fire you don't need the additional stiffnes anyway.
At least I imagine it that way.

What wikipedia says on the tyre grip

A big bang engine is an unconventional motorcycle engine designed so that most of the power strokes occur simultaneously or in close succession. This is achieved by changing the ignition timing, changing or re-timing the camshaft, and sometimes in combination with a change in crankpin angle. The goal is to change the power delivery characteristics of the engine. A regular firing multi-cylinder engine fires at approximately even intervals, giving a smooth-running engine. Because of a big bang engine's power delivery imbalance, there exists more vibration and stress in the engine. Thus, the power peaks are very strong and can overwhelm the rear tire (if used in a motorcycle), but when the rear tire does slide, the temporary lull in power between power strokes generally makes the slide easier to catch.

[rscsr]

What type of frequencies are you talking about though?
I imagine a big vang engine would have higher amplitude of vibration but lower frequncy if you look at the torque output.. Unless ypu are talking about some other frequency?

basically my thinking is an even firing (4 cylinder) engine has torque pulses every 180°. A big bang could have one every 90° (and then no pulses). Basically it fires at twice the frequency when it fires.
So in essence, I think the tyre is becoming stiffer when the engine fires and when it doesn't fire you don't need the additional stiffnes anyway.
At least I imagine it that way.

What wikipedia says on the tyre grip

A big bang engine is an unconventional motorcycle engine designed so that most of the power strokes occur simultaneously or in close succession. This is achieved by changing the ignition timing, changing or re-timing the camshaft, and sometimes in combination with a change in crankpin angle. The goal is to change the power delivery characteristics of the engine. A regular firing multi-cylinder engine fires at approximately even intervals, giving a smooth-running engine. Because of a big bang engine's power delivery imbalance, there exists more vibration and stress in the engine. Thus, the power peaks are very strong and can overwhelm the rear tire (if used in a motorcycle), but when the rear tire does slide, the temporary lull in power between power strokes generally makes the slide easier to catch.

That sounds just like "conventional wisdom". And there is no source, so it is just heresay. That is the big problem, I couldn't find any proper source.
And this explanation doesn't make sense anyway. Why does this not happen with a screamer configuration?

[PlatinumZealot]

Could be what Honda is doing on turning into the corners? Keeps traction at the rear?

[Tommy Cookers]

What wikipedia says on the tyre grip
A big bang engine is an unconventional motorcycle engine designed so that most of the power strokes occur simultaneously or in close succession. This is achieved by changing the ignition timing, changing or re-timing the camshaft, and sometimes in combination with a change in crankpin angle. The goal is to change the power delivery characteristics of the engine. A regular firing multi-cylinder engine fires at approximately even intervals, giving a smooth-running engine. Because of a big bang engine's power delivery imbalance, there exists more vibration and stress in the engine. Thus, the power peaks are very strong and can overwhelm the rear tire (if used in a motorcycle) ....

each of these sentences above is wrong

anyway it was the 'screamer' NSR500 that won almost all the races when the 'big-bang' NSR500 almost never won
probably throttling off behaviour was the biggest effect of weird firing intervals (Mr Doohan hated the BB)
since 'slipper clutches' this aspect became irrelevant

regarding the M1 and R1 (supposed poster boys of BB) ...
according to the M1 boss Mr Furasawa they weren't BB
(yes he tried a BB version of the M1 crank)

search for crossplane in the 2 stroke thread (posts around Nov 2016)
or big bang of course

[PlatinumZealot]

Makes sense to me at least.

There are many variations but i found this illustration of the twin engine a good example showing some interpretation of the " bangs" but for illstration it is pretty good.

[ispano6]

And team boss Christian Horner said the debut of a brand new Mobil 1 fuel this weekend is a sign that the Red Bull-Honda partnership is working well.

"The great thing about Honda is that they are fully focused on working with Red Bull and Toro Rosso," he said.

"That is significantly different to what we were used to before. Our former engine supplier (Renault) used another fuel and oil partner for their factory team.

"But we are involved in all of Honda's development, and that includes the fuel and the lubricants. It's a true partnership," Horner added.

ExxonMobil's technical boss David Tsurasaki confirmed at Suzuka that the new fuel features chemicals "that have never been used in F1 before".

https://m.wheels24.co.za/FormulaOne/hon ... t-20191011

[f1rules]

dont know if it has been shared
https://pbs.twimg.com/media/EG1ZN_WWkAE ... name=large


shared by scarbs

Craig Scarborough
@ScarbsTech

who got it here i think
NOBU㌠ @JO3VHC
@n_mode_log
· Oct 13
ココからが俺の時間w
#f1jp

[Polite]

dont know if it has been shared
https://pbs.twimg.com/media/EG1ZN_WWkAE ... name=large
https://pbs.twimg.com/media/EG1ZN_WWkAE ... name=large

shared by scarbs

Craig Scarborough
@ScarbsTech

who got it here i think
NOBU㌠ @JO3VHC
@n_mode_log
· Oct 13
ココからが俺の時間w
#f1jp

ctrl c / ctrl V the AMG PU... lol

[Nonserviam85]

What wikipedia says on the tyre grip
A big bang engine is an unconventional motorcycle engine designed so that most of the power strokes occur simultaneously or in close succession. This is achieved by changing the ignition timing, changing or re-timing the camshaft, and sometimes in combination with a change in crankpin angle. The goal is to change the power delivery characteristics of the engine. A regular firing multi-cylinder engine fires at approximately even intervals, giving a smooth-running engine. Because of a big bang engine's power delivery imbalance, there exists more vibration and stress in the engine. Thus, the power peaks are very strong and can overwhelm the rear tire (if used in a motorcycle) ....

each of these sentences above is wrong

anyway it was the 'screamer' NSR500 that won almost all the races when the 'big-bang' NSR500 almost never won
probably throttling off behaviour was the biggest effect of weird firing intervals (Mr Doohan hated the BB)
since 'slipper clutches' this aspect became irrelevant

regarding the M1 and R1 (supposed poster boys of BB) ...
according to the M1 boss Mr Furasawa they weren't BB
(yes he tried a BB version of the M1 crank)

search for crossplane in the 2 stroke thread (posts around Nov 2016)
or big bang of course

Honda changed to Screamer in 1997 so they were successful with the BB as well. When Honda switched the NSR500 to a screamer in 1997, riders we're throwing themselves off all the time, only the skill of the rider could compensate, this is why Mick Doohan won an incredible 12 of 15 races that year.

The guiding philosophy in a big bang engine, is that the "relaxation time" is long enough between the time when the engine is applying force to the road (the first 90 or so degrees of crankshaft rotation, or ignition) and the time when it's going through the non-force applying functions of a four stroke engine (exhaust intake and compression), that the remaining 630 degrees allow the tyre to re-grip, such that if too much force is applied during that 90 degrees of ignition and the tyre begins to slide, there is still 630 degrees of non force application. This provides a buffer for the rider to not be sent over the handlebars

There is the other argument for using the big bang engine. It is the idea that a big bang configuration is able to somehow improve the quality of the feedback that a rider receives from the rear tyre, so that they can better understand what the rear tyre is saying to them. The philosophy is that with a big bang you can apply some sort of input, such as the application of throttle to a tyre, and be given in return a useable amount of time to determine what that input has done to affect the motorcycle. With a screamer engine, the input is constant and permanent, there is no time to "hear" anything other than the input signal, you never get the chance to "hear" the feedback signal.

All the manufacturers are using Big Bangs or Low Bangs (or even twin pulses) at this moment except Honda, it is MM talent who is able to tame the motorcycle and win, every other driver complains about how difficult the Honda bike is. This is similar to what happened in 97 when Honda used screamers first, Doohan's talent helped them win.

[Bill]

Honda gave up their screamer when moto gp adopted common Ecu ,they also using Big Bang

[rscsr]

What wikipedia says on the tyre grip
A big bang engine is an unconventional motorcycle engine designed so that most of the power strokes occur simultaneously or in close succession. This is achieved by changing the ignition timing, changing or re-timing the camshaft, and sometimes in combination with a change in crankpin angle. The goal is to change the power delivery characteristics of the engine. A regular firing multi-cylinder engine fires at approximately even intervals, giving a smooth-running engine. Because of a big bang engine's power delivery imbalance, there exists more vibration and stress in the engine. Thus, the power peaks are very strong and can overwhelm the rear tire (if used in a motorcycle) ....

each of these sentences above is wrong

anyway it was the 'screamer' NSR500 that won almost all the races when the 'big-bang' NSR500 almost never won
probably throttling off behaviour was the biggest effect of weird firing intervals (Mr Doohan hated the BB)
since 'slipper clutches' this aspect became irrelevant

regarding the M1 and R1 (supposed poster boys of BB) ...
according to the M1 boss Mr Furasawa they weren't BB
(yes he tried a BB version of the M1 crank)

search for crossplane in the 2 stroke thread (posts around Nov 2016)
or big bang of course

Honda changed to Screamer in 1997 so they were successful with the BB as well. When Honda switched the NSR500 to a screamer in 1997, riders we're throwing themselves off all the time, only the skill of the rider could compensate, this is why Mick Doohan won an incredible 12 of 15 races that year.

The guiding philosophy in a big bang engine, is that the "relaxation time" is long enough between the time when the engine is applying force to the road (the first 90 or so degrees of crankshaft rotation, or ignition) and the time when it's going through the non-force applying functions of a four stroke engine (exhaust intake and compression), that the remaining 630 degrees allow the tyre to re-grip, such that if too much force is applied during that 90 degrees of ignition and the tyre begins to slide, there is still 630 degrees of non force application. This provides a buffer for the rider to not be sent over the handlebars

There is the other argument for using the big bang engine. It is the idea that a big bang configuration is able to somehow improve the quality of the feedback that a rider receives from the rear tyre, so that they can better understand what the rear tyre is saying to them. The philosophy is that with a big bang you can apply some sort of input, such as the application of throttle to a tyre, and be given in return a useable amount of time to determine what that input has done to affect the motorcycle. With a screamer engine, the input is constant and permanent, there is no time to "hear" anything other than the input signal, you never get the chance to "hear" the feedback signal.

All the manufacturers are using Big Bangs or Low Bangs (or even twin pulses) at this moment except Honda, it is MM talent who is able to tame the motorcycle and win, every other driver complains about how difficult the Honda bike is. This is similar to what happened in 97 when Honda used screamers first, Doohan's talent helped them win.

please show me some sources to your claims. I couldn't find anything why a BB might be better. At least nothing scientific.

[Capharol]

I thought they stopped the show "Big Bang Theory" .......