Joined Jul 2006
11K Posts | 291+
Texas
If he does do this on the screamer which is entirely possible as I am sure he can ride any bike you guys will have to criticise him every week for not hanging back and dicing
If he does do this on the screamer which is entirely possible as I am sure he can ride any bike you guys will have to criticise hime very week for not hanging back and dicing. I don't think the ducati in screamer mode lends itself to dog-fighting even with him riding it.
Good point, because even with electronics in place it has a more violent power curve and will not be as easy to handle as the big bang/cross plane...
That's why I also suspect he will go for the "big bang" version as he has always done (well the less peaky one at least)
From what I have read the advantage of 'Big Bang' over 'Screamer' is in the gap between power pulses. A screamer engine has very little gap between power pulses and therefore allows little time for the tyre to regain traction. The big bang has a relatively large gap between power pulses and therefore the tyre has big (relative) pauses in power where it can regain traction. Therefore with all other things being equal (tyre, set up etc etc) a big bang engine will deliver better traction and tyre life than a screamer engine.
This was evident when Ducati gave Stoner a Big Bang engine at the start of the season and Stoners immediate response was "heaps more traction to the extent that it is pushing the front wide through the corner".
Hope this makes sense.
Yeah, remember Philip island where Rossi picked up a 10 sec penalty but still won by about 13 secs?
Actually the big bang engines main advantage over a screamer is a more useable throttle connection at high revs.
Its not really that simple at all.
Interestingly, The yamaha firing order at the moment is an immitation of Honda's VFR series road bikes. The cross plane crank is needed because its an inline 4, split the cylinders by 90 degrees and then the cylinders can all fall in one crank plane without altering the firing order.
I am sure the mechanics of engine design are extremely complex. But I don't think the question was how is the engine configured but more in relation to what is the advantage. By advantage I determined the question of advantage to be related to the performance as used by the rider. Now throttle connection is an advantage a rider feels as is my 'simple' explanation of how the output of the engine effects the performance of power through the tyre to the track which is what the rider feels and uses with differing levels of success.
I am yet to hear a rider comment on how his cylinders falling in one crank plane helped him win the race today. If I was inclined to use Emoticons I would insert one here but I am not so I won't. I will leave it up to you to pick which would be used!
Well, the point is that Rossi and Yamaha chose their 'long bang' firing order because of the feel it gave Vale at high revs. With the v4 that Ducati use that firing order can be achieved without the cross plane crank layout so they wouldn't be losing power with balancing shafts like yamaha do.
Joined May 2008
3K Posts | 79+
Southern Aridzona - Hell's doorstep.
Big Bang produces a flatter torque curve, theoretically allowing more predictable control throughout the rev range ..... bit of a wild ride just off idle ( well compared to a screamer ) ...... but there are also arguably negatives with it as well ..... eg.pulsing of the power as the rev's drop may be more wearing on the drive train and tyres.
Screamers give an increasing torque curve and peak at hogher revs and power ...... bit of a wilder ride when you get it to higher revs.
How it applies to Stoner and Rossi:
Stoner won on a screamer
WRONG!!!!!
It's all about inertia torque, the effect of bringing the con rods and pistons to a halt at T and B dead center. Each time a piston slow to a stop, it accelerates the crank. Restarting it removes energy from the crank. On a classic straight 4, all the pistons are coming to a halt at the same time, producing notable pulses of positive and negative energy in the drive system. This irregularity rises rapidly with RPM (Your RPM limit statement is also bogus!) to the point that it can travel down the drivetrain into the tire, producing irregular traction and sketchy feedback. On a crossplane I4 (or properly timed V engine), one bank of pistons is coming to a halt as an other is accelerating, This allows the inertial energy to be exchanger between piston pairs, so very little of it escapes the engine.
The old theory, that irregularly spaced power pulses give the tire time to grip, is also wrong. At high revs, the inertia torque pulses are actually stronger than the combustion pulses! Firing order is far less important than achieving minimal IT transfer (to the tires).
-Moo!
Aaahh ok.
However when referencing my comment originally which had nothing to do with revs or cranks and balancing shafts you suggested that it is not as simple as my comment suggests. So, since you referenced my comment it would be nice to actually get some sense of whether you believe my comment to have some or no resemblance of truth. Just so you you don't have to scroll back to read it I suggested that big bang has a longer gap in the power pulse which allows the tyre to regain traction as apposed to the screamer which has less gap and therefore offer the tyre less space to regain traction. Therefore with all things being equal a big bang offers the rider more traction at the rear wheel. True or false?
False.
Take a look at this for a good explanation: Clever ....
The second edition of Niel Spaldings motogp technology also has this all explained, with some graphs and pictures too. Good book if you like the tech stuff.
This is good to hear...Rossi deserves to be allowed to test after all he's done for Yamaha. They also probably didn't want to end their relationship on bad terms.
Joined Jun 2007
10K Posts | 1K+
Norah Head
I don't agree with your wrong assessment ........... I made a pretty good attempt to keep all the pulsing/vibration issues out of it and keep it to how the two firing orders compare to ride. Buggered if I want to get into the "big bang" v's "screamer" lab test argument .......... ever. But I will happily give an "at the bars" feel comparo. When someone asks such a simple question as the original asker/poster did ......... I'm pretty sure they wanted it kept simple.
Not sure I disagree with what you wrote other than "wrong"......... without access to a few years and a decent engine test lab that is.
So how would you describe how they feel?
I'm a bit surprisd you say the "big bang" is a peakier feeling engine.
Joined Oct 2007
4K Posts | 744+
Tuscany, Italy
It is true that Rossi changed his style on the Yamaha. He was more aggressive on the Hondas, both the NSR and RCV211. When he tested the M1 for the first time he chose the 90° crank version of the M1 over the 180° one and then adapted himself to that bike, riding more fluidly. In turn Furusawa adapted the Yamaha even better, in 2008, to that "sweeter" style.
Meanwhile came Lorenzo, whose "mantequilla" (butter) style is ideal for extracting the maximum from the M1. After two years of hard apprenticeship, Lorenzo's style has gelled beautifully with the M1 now in its maturity -- even better than Rossi in fact, who by nature is a more aggressive kind of rider.
So Rossi at Ducati will probably revert to the style of his early days. It will be a little like going back home. More so in 2012, with the 1000cc.
Meanwhile came Lorenzo, whose "mantequilla" (butter) style is ideal for extracting the maximum from the M1. After two years of hard apprenticeship, Lorenzo's style has gelled beautifully with the M1 now in its maturity -- even better than Rossi in fact, who by nature is a more aggressive kind of rider.
So Rossi at Ducati will probably revert to the style of his early days. It will be a little like going back home. More so in 2012, with the 1000cc.
finally the 2 questions everyone has been wondering will be answered.
How good exactly is stoner?
How bad exactly is the ducati?
How good exactly is stoner?
How bad exactly is the ducati?
Thanks Tom, Good article. Not sure he complete discounted the gap in power and the result it creates with traction. The article just goes to show how technical the sport is and as a result how much of a team sport it is. Gone are the days of the mechanic in the pits tuning up the carbie of the 2 stroke so it is perfectly lean and fast.
I know that some fans believe it is all about the rider. Well without the engineer they would be riding push bikes!
