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post #1 of 19 (permalink) Old 03-02-2005, 08:25 PM Thread Starter
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Traction control or BS??

Traction control rife in Qatar.

The surprise occurrence in World Superbikes this weekend at Qatar was the 200bhp+ WSBK machines and their level of rear wheel sliding out of corners or lack of it.

This year sees the most powerful Superbikes ever take to the field with some of the four-cylinder machines rumoured to produce nearly 220bhp. Why then, at the first round of the championship at possibly the most slippery track of the calendar, were none of the front running rider's rear tyres being slid out of the corners.

Last season it was obvious the riders had more than enough power to instigate a beautifully controlled power slide, it would be thought with more power this year that it would have been a more regular occurrence. However, there was little or none of this taking place at the first race of the 2005 season.

The first indication that many of the machines - namely the Suzukis, factory Ducatis and Yamahas were using traction control was the lack of rear wheel sliding. The second indication was the hovering engine note whilst the bikes exited the fast sweeping corners. This was due to the traction control kicking in to limit the engine's revs momentarily as the rear tyre loses traction.

British teams have already admitted that a traction control system is used by Ducati and also Yamaha, who have a bolt-on kit available for any of its racing customers.

It is not known exactly how the respective manufacturers chose to restrict the amount of power going to the rear wheel, although restriction of engine revs is possibly the easiest and simplest way.

Control of this could possibly happen using the front and rear wheel speed sensors. If there is a considerable difference in the two wheel speeds, the ECU will limit the opening of the throttle bodies, restricting the amount of air and fuel mixture entering the engine and thus stopping the revs from rising.

However with the advent of a GPS telemetry sensor, making it able for teams to plot exactly where their rider is on track, and rumours of teams developing big-bang Superbike engines, there is likely to be a great jump in technological development in the foreseeable future with these traction control systems, seen in action in Qatar, being a simple but effective starting point.

Is it weird in here, or is it just me?
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post #2 of 19 (permalink) Old 03-02-2005, 09:37 PM
 
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Growler R1?

Given Rossi's success in MotoGP on the Yamaha, especiallyas (if I'm not mistaken) this is the first time in recent GP history that the championship has been won by anything other than a V engine (Rossi's bike is an I4), I pose the following to you:

How long before Yamaha make a Growler engine R1? (Big-bang firing order).

Technically it can't be that difficult and it would be an amazing machine for WSB, BSB, AMA........ bung in a traction control machine and even Legend would have trouble highsiding it. .

I'd say a round on me if we don't see a growler R1 on the grids by 2007. And if that wins you can rest assured that the days of screaming inline 4s are numbered.

All the Jap bikes will sound like Ducatis...



Last edited by MSS37; 03-02-2005 at 09:40 PM.
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post #3 of 19 (permalink) Old 03-02-2005, 09:41 PM
 
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not sure

Where was that invention in 2002 when i was doing the human cannon ball at Sepang.

The problem as i see it is that in order to compensate you have to measure the difference between the front and rear wheel. By the time you can measure the difference the rear has broken away. Ok "watching" the rear shock will help towards "predicting" when it's gonna break loose but still.
I've got more faith in GPS and setting the rev limit for each corner during practise. The pro riders are so consistant that this could be a way forward. At the end of the day spinning the rear up is still loss of traction and therefore speed however you look at it!
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post #4 of 19 (permalink) Old 03-02-2005, 10:02 PM
 
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Mmmmm

I thought all the manufacturers had come back from the big bang theory cos tyre development had moved on! If i remeber rightly the last 2 years of the GP 500s were running the 90 degree firing order again ( well most of the riders).
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post #5 of 19 (permalink) Old 03-03-2005, 03:12 AM
 
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Technical Numpty

Okay, I'm the first here to admit i dunno what the fark you're all banging on about now.

Pls can we have a layman's guide from our Technical Guru and all round Armcahir General, Mr Big Phil.

Yrs confused from Tunbridge Wells
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post #6 of 19 (permalink) Old 03-03-2005, 03:58 AM
 
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If you look at a four-stroke engine, there is a "bang" from a piston every 720 or every 2 revolutions of the crankshaft. In an 4 cylinder, engine, if you divide 720 by 4 you get 180 so evenly spaced piston firings would give you one bang every half turn of the crankshaft and this is exactly what an I4 engine does. An I4 is the type of engine which is in nearly all Jap sportsbikes except the SP1 and SP2 and TL1000.

Having bangs every 180 of crank rotation is really nice cause it gives you smooth power and that "screaming' noise all Jap sportsbikes make. However, once the rear tyre starts to spin, keeping it under control will tax even the most experienced riders- most of us will get a grandstand view as we highside the bike.

With a twin say like a Ducati which has a 90 V angle, the firing order of the bike is

bang (90) bang (270, 360), repeat ad infintum or in laymans terms, bang-bang, pauuuuse, bang-bang pauuuuse, etc. When speeded up to 10,000RPM it sounds like a growl more than a scream.

The reason that this is interesting is that despite the power advantages that I4s have, many riders love the way the twins deliver their power and current thinking is that this is to do with the firing order which with the long 630 of crankshaft rotation before the next bang, gives the tyres a chance to regain grip when the rears are sliding.

When Ducati developed their Desmosedici GP bike, they used a V4 and had a choice of firing orders, either "Bing Bang" ie like a twin it all happens at once and then nothing for a long pause, etc or a more even firing order like an I4.

They ended up going for the even firing order to get more power and longevity and as everyone saw in 2003, the Ducatis had no shortage of power but keeping it under control was another issue. Suddenly, the Ducatis were screaming whilst the Hondas were growling.

In 2004 they decided to switch to the big-bang growler engine configuration and immediately the riders were happier with the power delivery even though it made slightly less power. However, tinkering with other parts of the bike screwed up other aspects of the bike. All of a sudden their bike growled not screamed.

Yamaha was unique in 2004 because they had a I4 engine, just like your R1 but they decided to do a big-bang engine on it and judging by the results, the gamble paid off (thanks in no small part to a certain racer). And the bike sounded like a Ducati. This is significant because conventional wisdom says to win in racing you need a V engine for exactly for the power delivery.

The main reason that the Japs love the I4s over the V engines is cost, less valvetrain, machining costs, complexity etc. Now Yamaha has proven that you can have the best of both worlds, V engine characteristics with the cost of an I4 without resorting to fancy traction-control shit.

Hence my comment about the likelihood of a Growler R1 although I suspect it might be a homologation special at first.

Last edited by MSS37; 03-03-2005 at 04:02 AM.
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post #7 of 19 (permalink) Old 03-03-2005, 01:51 PM Thread Starter
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I know the article suggests otherwise but I think using wheel speed sensors to limit revs when needed (ie. traction control) will play a bigger role here than the firing order did back in the two stroke days (the big bang theory).....

They might not only sound more like a duke MSS, they'll beat them so bad they'll won't bother turning up

Is it weird in here, or is it just me?
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post #8 of 19 (permalink) Old 03-03-2005, 03:36 PM
 
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There are far too many technical people on this forum

BC? Wanna chat about something simple? Quantum Physics for example? or the relative merits of lowsiding Yamahas?
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post #9 of 19 (permalink) Old 03-03-2005, 04:55 PM
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Re: not sure

Quote:
Originally posted by bigphil
Where was that invention in 2002 when i was doing the human cannon ball at Sepang.

The problem as i see it is that in order to compensate you have to measure the difference between the front and rear wheel. By the time you can measure the difference the rear has broken away. Ok "watching" the rear shock will help towards "predicting" when it's gonna break loose but still.
I've got more faith in GPS and setting the rev limit for each corner during practise. The pro riders are so consistant that this could be a way forward. At the end of the day spinning the rear up is still loss of traction and therefore speed however you look at it!
With 32 bit ECU's the speed of the system will be more than enough to cope with the adjustments, lets face it its gonna be faster than a rider can work it out and it was fast enough for 1000hp F1 cars.
The next issue is anti wheelie control, I kid you not.
Link the wheel sensors or tilt switch to an ABS unit and your away. The worst part about all of this is it very quickly becomes less about the rider and more about the technology. Imagine a bike with Traction control, wheelie control and ABS, no skill required and Moto GP is transformed into two wheel multi million pound shopping trolley racing. I think Suzuki are already playing with this kind of jiggery pokerry.
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post #10 of 19 (permalink) Old 03-03-2005, 05:04 PM
 
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Re: Technical Numpty

Quote:
Originally posted by Blue Catt
Okay, I'm the first here to admit i dunno what the fark you're all banging on about now.

Pls can we have a layman's guide from our Technical Guru and all round Armcahir General, Mr Big Phil.

Yrs confused from Tunbridge Wells
The original theory was based upon this. Everytime a cylinder fires the piston pushed the crankshaft which in turn, through the gearbox etc. pulled the chain and therefore the back wheel turned. As this happens the tyre distorts a bit while pushing the bike forward. Because a 2 stroke fires every rev and there were 4 cylinders. A 90 degree firing order meant the tyre was continually getting distorted. It was found that if you had all cylinders firing very close to each other, in say 30 degrees. The tyre had more time to recover ready for the next bang. And it worked for some riders. The engines were wild as fark.
There's loadsa other problems associated with the big bang engine like carbs and crankcase pressures etc.
Some riders couldn't handle the power delivery at all, way too wild. But the experts of the day Doohan and Criville were a joy to watch.
The DVD " faster" suggests that McCoy was the first to smoke a back tyre. Thats Bollocks! You look at Criville in his time. That boy could power slide a big bang bike.

Bored yet gareth
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