MotoGP RPM limits

<div class='quotetop'>QUOTE (SackWack @ Mar 17 2008, 11:33 PM) <{POST_SNAPBACK}><div class='quotemain'>Did a google search for 20, 000 RPM and this is what popped up
HERE

Thats kind of funny.


lol perfect fit for dani????

dude thats hilarious yam and honda cant get a gp bike to 20,000 rpm but you can with a pocket bike WTF lol........

50cc Single cylinder, Water-cooled, 2 stroke
8.0 Kw(10.88HP) @ 20,000rpm

bring back the 2-stroke

Hyper, I agree with you that the 200 needs to be a superbike race. I will go further and say that there are too many classes in AMA. Why do we need more that three classes? Superbike, supersport, and superstock. You imply that Suzuki has an unfair advantage over honda? Sorry I am not buying that the mighty Honda could not afford what Yosh Suzuki could. As far as Ducati goes they wanted substantially more than regularity of traction control. they wanted their usual level (slanted heavily in Ducati's favor) playing field. I am also not buying Ducati as the poor downtrodden factory that is just trying to catch a break. If two other riders besides Neil and Ben were on the same bikes they would have been very competitive, for instance Troy Bayliss. They had slow riders who were all too eager to cry foul at the end of the season, which I saw as a convenient excuse why they did not get the job done. I think Hodgson is the luckiest world champion ever. Ben Bostrom has been unmotivated for years.

<div class='quotetop'>QUOTE (michaelm @ Mar 17 2008, 08:06 PM) <{POST_SNAPBACK}><div class='quotemain'>The new F1 rules rather than allowing the drivers to display their driving skills seemed to allow them to display the absence of such skills,

absence of proof does not mean proof of absence

<div class='quotetop'>QUOTE (michaelm @ Mar 17 2008, 01:06 PM) <{POST_SNAPBACK}><div class='quotemain'>I agree. The new F1 rules rather than allowing the drivers to display their driving skills seemed to allow them to display the absence of such skills, and without changes to the aerodynamics overtaking still appears to be difficult. The youngest drivers with the least experience of the absence of traction control seemed to do best.

I am not arguing that this has anything to do with what the technology should be in motogp, just that following the lead of F1 is not necessarily a good idea, given that their decisions for the last decade or so have been almost universally stupid.
This is partly why people who would like to see the influence of the electronics limited in Motogp feel that way. In F1, some drivers who have been considered "world class" with the electronic aids are appearing to be slightly less than world class at the moment. I realise that there is bound to be a learning curve, but would have thought that winter testing would have solved much of that.

Any racing series which considers itself the pinnacle of the sport should attract the best drivers/riders, not ones which are flattered by any electronic gizmos. Removal of the gizmos helps to show who actually has the most talent out there.

<div class='quotetop'>QUOTE (yamaka46 @ Mar 18 2008, 09:31 AM) <{POST_SNAPBACK}><div class='quotemain'>This is partly why people who would like to see the influence of the electronics limited in Motogp feel that way. In F1, some drivers who have been considered "world class" with the electronic aids are appearing to be slightly less than world class at the moment. I realise that there is bound to be a learning curve, but would have thought that winter testing would have solved much of that.

Any racing series which considers itself the pinnacle of the sport should attract the best drivers/riders, not ones which are flattered by any electronic gizmos. Removal of the gizmos helps to show who actually has the most talent out there.
I don't disagree with you, I am just re-stating my essential position on F1 which is that overtaking on the track is very difficult in the presence of the current aerodynamics, so I don't think getting rid of tc etc but leaving the aerodynamics intact will lead to much more overtaking, and hence any opportunities to display driving talent will be restricted to making the end of the race without crashing rather than using such skills to overtake. I am all for getting rid of the more obtrusive driver aids if it is in addition to changes to aerodynamics. The melbourne F1 race looked like a nascar race in terms of safety car periods, which I think negates gains made by good driving, and the punt mid-corner does not seem to be an effective overtaking move in F1.

<div class='quotetop'>QUOTE (yamaka46 @ Mar 18 2008, 08:31 PM) <{POST_SNAPBACK}><div class='quotemain'>Any racing series which considers itself the pinnacle of the sport should attract the best drivers/riders, not ones which are flattered by any electronic gizmos. Removal of the gizmos helps to show who actually has the most talent out there.

Yes but the significance of Electronics aids pales into insignificance when one considers that much of the reasons that the riders selected are based on the possibility that those riders attract fans from their home country.

<div class='quotetop'>QUOTE (michaelm @ Mar 18 2008, 10:01 AM) <{POST_SNAPBACK}><div class='quotemain'>I don't disagree with you, I am just re-stating my essential position on F1 which is that overtaking on the track is very difficult in the presence of the current aerodynamics, so I don't think getting rid of tc etc but leaving the aerodynamics intact will lead to much more overtaking, and hence any opportunities to display driving talent will be restricted to making the end of the race without crashing rather than using such skills to overtake. I am all for getting rid of both the more obtrusive driver aids if it is addition to changes to aerodynamics. The melbourne F1 race looked like a nascar race in terms of safety car periods, which I think negates gains made by good driving, and the punt mid-corner does not seem to be an effective overtaking move in F1.
I'd agree with you there. Alain Prost in 1994 and Damon Hill in 1997 both had it right IMO. Get rid of most of the aerodynamics, big sticky tyres and unlimited cylinders (have you heard the v8s - they sound dreadful in real life). As far as Safety Cars are concerned, I'm all for safety, but the rules about being not able to refuel at the start of the SC period are crazy. You either need to break the rules to stay in the race (a la Barrichello) or lose track position once the pits are "open".

Anyway, back to topic....

they should have limits on how many undies changes u can make

<div class='quotetop'>QUOTE (ogunski @ Mar 18 2008, 02:08 AM) <{POST_SNAPBACK}><div class='quotemain'>Hyper, I agree with you that the 200 needs to be a superbike race. I will go further and say that there are too many classes in AMA. Why do we need more that three classes? Superbike, supersport, and superstock. You imply that Suzuki has an unfair advantage over honda? Sorry I am not buying that the mighty Honda could not afford what Yosh Suzuki could. As far as Ducati goes they wanted substantially more than regularity of traction control. they wanted their usual level (slanted heavily in Ducati's favor) playing field. I am also not buying Ducati as the poor downtrodden factory that is just trying to catch a break. If two other riders besides Neil and Ben were on the same bikes they would have been very competitive, for instance Troy Bayliss. They had slow riders who were all too eager to cry foul at the end of the season, which I saw as a convenient excuse why they did not get the job done. I think Hodgson is the luckiest world champion ever. Ben Bostrom has been unmotivated for years.


NO, not at all implying that Suzuki has an advantage over Honda. Suzuki went a really cool and innovative route, doing engine management to achieve traction control. Honda apparently doesn't care enough to do the same, but they have more resources than anybody to do it if they want. Suzuki has been very good at innovation, to wit, the GSXR when it came out, much lighter and better than any other Japanese 4 cyl.

Ducati is looking for some parity with 2 cylinders, and yes, they wanted more than traction control, but when they pulled out, even traction control wasn't on the table. Ducati employs 900 people. Honda has that many in the handlebar controls department. Ducati was losing money just a couple years ago, and has no big war chest. Each year, Honda probably has more profits than Ducati has made in its lifetime. But the AMA does not reward either privateers nor small companies.

Hyper

I don't think this arguament has anything to do with number of employees or how much profit each manufacturer turns over. Ultimately the accounting departments at places like Yamaha and Honda are less likely to feel the difference in sales if they stop racing than someone like Ducati, who rely on competition for sales. For this reason it is legitimate for them to be concerned with spiraling budgets that come with chasing high RPM engines.

However i think that a rev limit is a terrible idea, simply because the limit set will be easily achievable and we will see the bikes getting increasingly similar. Just like with tyres and electronics, i think specifying technical solutions to such a large extent is a bad idea regardless of who currently has the advantage.

<div class='quotetop'>QUOTE (mylexicon @ Mar 17 2008, 03:24 PM) <{POST_SNAPBACK}><div class='quotemain'>If my memory serves me correctly we didn't have a "rev" problem in 2006. Reducing power is what has ruined the sport. If they wanna slow things down they should increase width requirements. More drag means 10 extra hp doesn't do jack at 300kph. There would be tons of passing on the straights, and the riders would have a protected cockpit instead of hanging out in the breeze. They could have unlimited fuel and it still wouldn't help them get down the straights much faster.

I'm against a rev limit because it is baloney. 1 stupid rule that changed displacement to 800cc has caused bedlam. The change to 800cc has been an unmitigated failure because it has increased cost, number of rules, and it has failed to make anything safer.

Plus, this is so predicable. A big bang I-4 is made for hooking up at low rpm and Honda are too pathetic to get their pneumatic program off the ground. Two companies stuck in their ways. Honda with it's stupid narrow angle engines and spring valves and Yamaha with its refusal to try new engine configs.

Why isn't Desmo better?

The smaller the engine the better it is because the relative power loss from valve actuation is constant (assuming valves shrink too). The relative power loss from springs grows as the engine gets smaller and revs higher. Plus, desmo utilizes the mechanical advantage of leverage and isn't a closed system like pneumatics and it doesn't have energy loss from gas compression.

The only thing that will beat Desmo for small displacement engines is electromagnetic valve actuation. The teams should be working on that instead of whining for rules changes.

Plus, its not just Desmo. Ducati run an L-4 with screamer firing. It's naturally balanced unlike narrow V's and it's better balanced and narrower than an I-4. Even with a change, Ducati would probably still have 10kph on the field. They would stroke the engine, reduce cylinder width, and maintain similar speed and have even more low end grunt.

4 points. For one thing I doubt the primary advantage of using an I4 is low end hookup. All the I4's I have owned liked to rev and as the revs built tended to kick out the rear end as they spun up which made me conclude they don't put the power down very well. My current 1L twin is exceptional in this area. Secondly, the L engine has a natural "big bang" firing order so you can make this engine with evenly spaced crank journals for balance but the firing order is not even. A screamer !4 is going to be even unless you offset the rod journals purposely. Thirdly, I doubt in practical terms whether desmo is better than pnuematics. With the desmo system you have a lot of additional whirling hardware to accelerate and decelerate. I think I'd go with a properly designed and tested pnuematic system any day. Fourth, I am in agreement with you that the aero package would be a very effective way to slow the bikes down. More so with the 800cc engines.

The transition to the 800cc race class prototypes has been hard but the racing will benefit in the long run because the machine can be cornered hard whereas the 990's were slow in that area. Without the corners there is no motogp. Without corners who needs motorcycles?

<div class='quotetop'>QUOTE (gsfan @ Mar 19 2008, 05:03 PM) <{POST_SNAPBACK}><div class='quotemain'>Thirdly, I doubt in practical terms whether desmo is better than pnuematics. With the desmo system you have a lot of additional whirling hardware to accelerate and decelerate. I think I'd go with a properly designed and tested pnuematic system any day.

The transition to the 800cc race class prototypes has been hard but the racing will benefit in the long run because the machine can be cornered hard whereas the 990's were slow in that area. Without the corners there is no motogp. Without corners who needs motorcycles?

There is not a lot of additional whirling hardware with desmo vs conventional gear, although of course there is more. However the real difference is the amount of horsepower required to actuate any sort of movement under two different loading situations. With desmo operation, the only loading agent is friction, and indeed there is a certain amount of help in some direction from pressure as in the exhaust valve being helped to close by the cylinder pressure, while the cylinder pressure to open is the same for all types of valve gear. In contrast, any valve system that relies on pressure means of any sort creates a very noticeable drag of the lifter versus the cam lobe. As the cam becomes more radical, with steep opening ramps, this drag increases significantly. In addition, the pressure increases the actual friction amount between follower and cam lobe. At higher rpm limits, the friction increases significantly, as does the loss of horsepower due to overcoming the return force of the valve in non desmo systems.

Other possible methods of intake and exhaust may include some sort of rotary valve using computer timed stepper motors perhaps, and this would be a way to eliminate the significant friction introduced by spring or pneumatic valve return. So it seems that not limiting RPM would be the best way to actually lead companies to increase knowledge of how to build better and more efficient engines.

I like your idea of increasing the wind drag coefficient, but this is something NASCAR does in determining how much a windshield can be lowered (or raised) to promote equality of racing and could be a bad thing. It would depend greatly on how it is implemented, because done like NASCAR does it, it would enable less efficient engine layouts, such as Yamaha uses, to be put on an equal basis with better designs.

Hyper

I would be interested to know if the losses from friction in a low pressure nitrogen system (~45psi) would equal the loss to the additional inertia forces in the desmo system. Until then I will consider it equal so the maintenance factor comes into play as the deciding factor. A short shot of nitrogen in the tank under the seat seems preferable to yanking off the valve covers and resetting 32 clearances.

For the aero restriction the basic concept is good because it doesn't hit the pocket book unevenly for teams. The rule could specify say .5 or some arbitrary coefficient of drag which could be easily determined. The shapes could still be modified for crosswinds depending on the track as long as the drag is the same. There are already limitations on the fairing shape.

It is worth considering that the japs don't want pneumatic valves to become the norm because it is technology they don't need to develop outside of racing. F1 has had pneumatic valves for approximately 20 years but still the technology is useless to road cars, how can Honda and Yamaha justify the financial outlay to develop this technology when they wont sell it. It's the two stroke dilema all over again, except that ducati aren't faced with this problem.

<div class='quotetop'>QUOTE (Pinky @ Mar 18 2008, 09:38 PM) <{POST_SNAPBACK}><div class='quotemain'>they should have limits on how many undies changes u can make


just like this forum should limit the amount of stupid post you can put here in a day!!!!

<div class='quotetop'>QUOTE (jazkat @ Mar 20 2008, 12:11 AM) <{POST_SNAPBACK}><div class='quotemain'>just like this forum should limit the amount of stupid post you can put here in a day!!!!


How to kill this foum in one day!

<div class='quotetop'>QUOTE (gsfan @ Mar 19 2008, 07:40 PM) <{POST_SNAPBACK}><div class='quotemain'>I would be interested to know if the losses from friction in a low pressure nitrogen system (~45psi) would equal the loss to the additional inertia forces in the desmo system. Until then I will consider it equal so the maintenance factor comes into play as the deciding factor. A short shot of nitrogen in the tank under the seat seems preferable to yanking off the valve covers and resetting 32 clearances.

For the aero restriction the basic concept is good because it doesn't hit the pocket book unevenly for teams. The rule could specify say .5 or some arbitrary coefficient of drag which could be easily determined. The shapes could still be modified for crosswinds depending on the track as long as the drag is the same. There are already limitations on the fairing shape.


Actually it would make little difference how the pneumatic is effected (nitrogen or whatever), the same principle must always apply. The pressure exerted by the pneumatic coil must be more than the required force required to slam the valve shut once the cam lobe is past the high point and is on the low part of the lobe. Whether done by spring or pneumatic, it makes no difference, the amount of force applied is the same, and thus creates the same drag component. The reason for going to pneumatic valves is because of valve float. At the higher RPM, the ability of the steel to push back becomes less and less consistent, hence float occurs. Given the high compression, that yields valve-piston interference and engine failure, perhaps that explains some of the difficulties that Rossi has had with the Yamaha. The desmo has exactly the same inertia to overcome as far as the valve actuation but without the extra friction and horsepower loss required to overcome the spring tension. To get an idea of the difference, find a desmo head and a regular valve spring head (some older Ducatis used springs, not desmo) and compare the difference in effort per revolution.

Also, the valve adjustment aspect remains unchanged. There is still the same exact amount of valve train requirement to open the valves and allow the spring (steel or pneumatic) to close the valve, and there must be a gap between the valve and the opening device or else the valve will remain open, lose compression, and quickly burn up and fail to seal. So the only difference between coil springs as Japanese and other bikes use and pneumatic is that you might also lose pressure, and that would cause engine failure as valve fails to close. With the desmo system, changing to the Martin Brickwood collets usually yields 30k + mile ranges between valve adjustments, so its not really an issue there either. Of course for racing motors on the MogoGP circuit, more frequent attention is paid no matter what type of valve train is used.

Hyper

<div class='quotetop'>QUOTE (Hyper @ Mar 20 2008, 11:52 AM) <{POST_SNAPBACK}><div class='quotemain'>find a desmo head and a regular valve spring head (some older Ducatis used springs, not desmo) and compare the difference in effort per revolution.
Hyper

Really good point!


which makes me wonder why some of the other manufacturers don't do the positive valve return thing like a desmo ..... I'm pretty sure they are not limited by patent ...... is it just a pride thing? .... don't want to be seen as copying?

For sure the desmo is easier to turn than a coil spring valve train that requires very stiff springs to work at high rpm. However, I suspect that same force preload is not present in a pneumatic valve train.

This article has good info:

http://www.sportrider.com/features/146_070...r990/index.html


<span style="color:#8B0000Fixed link

<div class='quotetop'>QUOTE (gsfan @ Mar 20 2008, 04:38 PM) <{POST_SNAPBACK}><div class='quotemain'>This article has good info: http://www.sportrider.com/fetures/146_0704...r990/index.html

Could you get us a link that work.