MotoGP 2018

[speights_bud]

Fp1 mechanical issue for Rossi.

Looks like the rear sprocket flew to pieces

Sent from my SM-G900I using Tapatalk

[mulletman]

Fp1 mechanical issue for Rossi.

Looks like the rear sprocket flew to pieces

Sent from my SM-G900I using Tapatalk

Sounded like a Ducati clutch when it went.

[Drew]

I never realised Honda went big bang firing order again due to the electronics limitations. Explains why they are easier to ride compared to a few years ago.

How does that explain why they're easier to ride?

I cant ride a twin to save myself, which is what big bang essentially is.

[husaberg]

How does that explain why they're easier to ride?
I cant ride a twin to save myself, which is what big bang essentially is.

In some ways its like a V twin but its also give a four stroke feel on a two stroke as well.
It doesn't show up on a dyno curve, but in real life situations it seem to work until traction control or tyre technology catches up with engine performance.
No one really knows for sure why, but most say it s tyre recovery as it has more time between bang to grip effectively.
Although some totallly disagree with that as well.
The way i look at it Look at how well a single hooks up in the dirt compared to a twin or a four.
But in the two stroke era it certainly worked rather dramatically.
With Doohan back in 91 or 92 the lap times were the same but the tyres lasted longer. So he could use a softer tyre or ran faster for longer on the same tyres.
if you ride a CBR400 and a VFR400 back to back the vfr has a very different feel in its delivery, yet has pretty much the same spec as the CBR400

HRC’s Shigeru Hattori took over as NSR500 project leader at the dawn of the Big Bang era and has held that position ever since. According to Hattori, the Big Bang configuration didn’t significantly change the power curve, midrange power output or even the peak power as seen on a dyno. What it changed was the way in which that power was delivered to the pavement—in this case, four pulses in rapid succession followed by a long pause.

Developments of the 91 NSR 500 focused around Doohan testing a number of designs as HRC shifted their main push behind the new up and comer... For some while Doohan had been asking engineers to replicate the wide power band characteristic of the RVF750 4 stroke endurance bike, which he and Gardner had used to lead the previous summer's Suzuka 8 Hours... HRC answer was the 2 stroke equivalent of the the 4 stroke Big Bang... technically speaking all four cylinders fried within 70 degrees to afford the tire more time to hook up..."

"Consider and instant success by Gardner "Jesus, this is amazing" but Doohan was a doubter... the 92 NSR droning big bang had a very flat exhaust note which made it sound slow to riders... It was only
during HRC's final preseason phase that Doohan began to believe in theBig Bang... He found little difference in lap times but the close firing order was easier on tires and set up..."

Rainey and company were in for the shock as the season kicked off...Utilizing the Big Bangs ability to find traction where others could not... Doohan ran away with the first four races... winning by
anything up to 28 seconds wet or dry... The Big Bang proved such a giant leap forward that rival factories Cagiva, Suzuki, Yamaha rushedto build copies... having learned the NRS's secret by playing
track side audio recording against an oscilloscope..."

HRC built several different motors in their search for that user-friendly power delivery. Finally, they settled on the Big Bang, that fired all four cylinders within 70 degrees, giving the rear tire time to regain traction between each salvo.
But it took Doohan a while to fall in love with the droning motor. HRC man Shoji Tachikawa remembers: "The engine note made it sound slow, so riders thought they were going slow. Mick was very surprised when he came into pits and saw his times."
In fact lap times weren't faster but they weren't slower either and the reduced wheelspin improved tire life, so race times were faster.

Changing the combustion timing didn’t merely change power delivery, it transformed the way the motorcycle handled, steered and everything else.
“HRC realised that handling isn’t just a chassis deal,” said ace tuner Erv Kanemoto at the time. “The change to a 180-degree motor made the traction better and changed the steering. The next step was the big bang. Honda improved the handling immensely, just by changing the engine character.”
Now, a neat quarter of a century later, HRC has gone big bang once again. Back in 1992 HRC engineers needed to tame the NSR’s two-stroke power delivery. Now they need something different because their experience of Dorna’s same-for-all software last year told them it isn’t clever enough to tame a screamer RC213V engine.
So far it seems to be working. At Phillip Island last week, Repsol Honda riders Marc Marquez and Dani Pedrosa and LCR Honda’s Cal Crutchlow made it three RCVs in the top five, with Jack Miller ninth, ahead of Valentino Rossi and Andrea Iannone.
Miller was a bit more direct than Kanemoto in his assessment of how a big-bang engine changes the dynamics of a motorcycle.
“I notice it here, really a lot,” said the Australian at Phillip Island. “Especially turn 10 to turn 11 [the MG right-hander to the next left], where you’ve got two gear shifts and a change of direction at the same time. It definitely feels a lot better there. It’s just a smoother engine and seems a lot more user-friendly. It’s more calm for the rider and you can focus more on hitting the lines, rather than battling to keep the bike in a straight fucking position!”
Factory HRC men Marquez and Pedrosa used a newer-spec engine at Phillip Island, with Marquez still adjusting to the big-bang concept, just like Mick Doohan had to in 1992.
“At the first few tests I was quicker with the 1991 NSR,” said Doohan. “It wasn’t until our last test that the new bike was faster. Wayne [Gardner] liked it more than I did because it suited his style. He didn’t carry any corner speed and the big-bang motor let him do what he wanted – park the bike in a turn, pick it up and give it a handful. The old motor wouldn’t accept that.”
An RC213V is very different from an NSR500, but the big-bang concept is essentially the same with both bikes. It bunches the explosions closer together to create a lazier vee-twin kind of power which creates less wheelspin because the bigger power pulses increase load on the rear tyre to improve grip, then the pause before the next salvo allows the tyre to settle down and get ready for the next push. Big-bang engines also cause fewer wheelies, save the tyre and generally make a motorcycle less demanding to ride, especially over race distance.
So a big bang must be a win, win, win, win, right? Yes, but in racing there is good and bad in everything; it’s all about compromise. More evenly spaced firing-order engines do have their advantages: most importantly more peak power and lower fuel consumption, a vital factor a few years ago when MotoGP bikes raced with 20 per cent less fuel than they have now. Also, most of their downsides could be mollified with clever electronics programmes, but no longer, due to unified software.
Yamaha went big bang in 2004, transforming its inline-four YZR-M1 into a pretend V4. Chief engineer Masao Furusawa had his own theory about the technology; that a big-bang configuration cancels out inertia torque, the effect of the crankshaft decelerating and accelerating during each stroke, which spoils the rider’s feel for what’s going on at the rear tyre.
Now there is only one factory running a screamer engine in MotoGP – rookie brand KTM. The Austrian company’s engineers say they are delighted with the engine character of the RC16 engine, but for how long? Bradley Smith and Pol Espargaro, both accustomed to the rider-friendly ways of Yamaha’s M1, are a bit wide-eyed about the KTM engine, the Spaniard talking about having to “tame the beast”. Time will tell if KTM makes the engine succeed with Dorna’s electronics.

Here is what kevin cameron has said.

[pritch]

There was talk of rain being possible at some time during the weekend but currently the forecast is for partly cloudy Saturday and Sunday with no rain until Tuesday. That'd be better.

[Mental Trousers]

In some ways its like a V twin but its also give a four stroke feel on a two stroke as well.
It doesn't show up on a dyno curve, but in real life situations it seem to work until traction control or tyre technology catches up with engine performance.
No one really knows for sure why, but most say it s tyre recovery as it has more time between bang to grip effectively.
Although some totallly disagree with that as well.
The way i look at it Look at how well a single hooks up in the dirt compared to a twin or a four.
But in the two stroke era it certainly worked rather dramatically.
With Doohan back in 91 or 92 the lap times were the same but the tyres lasted longer. So he could use a softer tyre or ran faster for longer on the same tyres.
if you ride a CBR400 and a VFR400 back to back the vfr has a very different feel in its delivery, yet has pretty much the same spec as the CBR400








Here is what kevin cameron has said.

I seem to remember that Frits did some work with big bang engines and the conclusion wasn't quite what everyone thought it would be. Best to dig through the ESE thread for it.

[husaberg]

I seem to remember that Frits did some work with big bang engines and the conclusion wasn't quite what everyone thought it would be. Best to dig through the ESE thread for it.

I have read Frits take I cant argue with his maths. Not just because hes a physicist either
But the riders feel is what wins races.
Frits certainly doesn't subscribe to the tyre rest theory. That Burgess and Willings and Cameron spoke of
But when tyres and electronic control were the limiting factor, each time the firing intervals on the NSR were further condensed it was easier to ride and easier on tires.

When Doohan went back to the screamer the tryes had got dramatically better fuel had changed as well as the ignition Even Doohan said the unleaded fuel had turned what was race motors into pussycats.
Put it this way all the successful engines now in Motogp are suddenly big bang again.....

[Mental Trousers]

I have read Frits take I cant argue with his maths. Not just because hes a physicist either
But the riders feel is what wins races.
Frits certainly doesn't subscribe to the tyre rest theory. That Burgess and Willings and Cameron spoke of
But when tyres and electronic control were the limiting factor, each time the firing intervals on the NSR were further condensed it was easier to ride and easier on tires.

When Doohan went back to the screamer the tryes had got dramitaclly better fuel had changed as well as the ignition Even Doohan said the unleaded fuel had turned what was race motors into pussycats.
Put it this way all the sucessfull engines now in Motogp are suddenly big bang again.....

You got a link to what Frits says? I want to read it.

[husaberg]

You got a link to what Frits says? I want to read it.

i think it was originally posted on Pitlane in a separate thread.
Either i or Jaw posted some of it on (i think) the oddballs and prototypes thread.
It was in response to JAW attempting to start an argument with Malcey over a TZ750 which is a two up set up.
Which was done this way by the designer to lessen rocking couple.
Okay i found that faster than expected
http://www.pit-lane.biz/t1461p32-tec...moteurs-motogp
you need to have a log in to see the pictures

[pritch]

Further to my weather forecast which, if you recall, was for partly cloudy. Herewith the Rookie Cup at the Red Bull Ring today.

[roogazza]

Year and a half now and Yamaha still behind the Eight ball.
For the good of racing I hope like everyone else, things can be fixed? (whatever the problem is ?).

We've had what, a year and a half of pondering ?

[pritch]

Year and a half now and Yamaha still behind the Eight ball.
For the good of racing I hope like everyone else, things can be fixed? (whatever the problem is ?).

We've had what, a year and a half of pondering ?

The pundits seem more or less unanimous and the commentators referred to it during Q1; it's their electronics.

When the rules stipulated Magneti Marelli as the control electronic system, Ducati and Honda poached Magneti Marelli engineers. Yamaha, for whatever reason, decided to rely on their own engineers. Experience would suggest that was the wrong decision. During practice Rossi was reported as making a similar comment to yours, to the effect that a year has passed since the last Austrian GP but there has been no progress, the same problems persist.


Such a lovely weekend weather wise, got the bike out yesterday and went on a group ride.

[pritch]

From the Ulster GP. A member of the crowd was taking photos with a selfie stick but he got a bit too close to the action. He was taken to hospital with a dislocated shoulder but is getting no sympathy. At the very least people on social media seem to think he owes the rider a set of leathers.

[BMWST?]

The pundits seem more or less unanimous and the commentators referred to it during Q1; it's their electronics.

When the rules stipulated Magneti Marelli as the control electronic system, Ducati and Honda poached Magneti Marelli engineers. Yamaha, for whatever reason, decided to rely on their own engineers. Experience would suggest that was the wrong decision. During practice Rossi was reported as making a similar comment to yours, to the effect that a year has passed since the last Austrian GP but there has been no progress, the same problems persist.


Such a lovely weekend weather wise, got the bike out yesterday and went on a group ride.

its more than electronics some say its the crank weight.....too light ,wont be solved properly till next year.

[pritch]

its more than electronics some say its the crank weight.....too light ,wont be solved properly till next year.

Well they've had over a year already. If the electronics worked they could at least minimise a crank weight problem. It would seem that now they are becoming aware that there is a problem; Yamaha have issued an apology to the riders.


http://www.motogp.com/en/news/2018/0...-fix-it/268133