| Author |
Message |
    
Grndskpr
| | Posted on Tuesday, May 27, 2003 - 08:31 am: | 
|
If you produce 150 collectors items in order to go racing are you truly a streetbike manufacturer?
Didnt Buell do that in the begining(read RR1000), i belive the production numbers for the first few years were under 150, everyone has to start someplace, it just that some choose to start in racing, and others on the street, it is a position i would love to be in however never will, please keep things in perspective
|
Jssport
| | Posted on Tuesday, May 27, 2003 - 02:35 pm: |
|
This is why why the 750cc 2-stroke class was cut back to 500cc
This was from an air cooled H2R...
*formatting errors* darn....
(Message edited by jssport on May 27, 2003, %time)
(Message edited by jssport on May 27, 2003, %time) |
Jssport
| | Posted on Tuesday, May 27, 2003 - 02:45 pm: |
|
  |
Jssport
| | Posted on Tuesday, May 27, 2003 - 02:48 pm: |
|
Hmmm,, got it loaded twice ??
Anyway you can see how the 750's would shred tires back in the early 80's. The TZ's shred them even more, Dale Singleton's Daytona winner had chunks missing from the front and the rear.
It was the riders themselves who wanted the limit cut back to 500cc,.. wise choice.
Eric's RW 750 did not factor into this decision. |
S320002
| | Posted on Tuesday, May 27, 2003 - 06:02 pm: |
|
Rocket,
"Ah Greg you're pissing in the wind."
Not so. I was raised on a farm. Us farm boys knew better than to do that by the time we were old enough to stand on two feet and hang it out.
"What company campaigns a superbike without success and to the point of embarrassment when allegedly they've got the words best motorcycling genius designer on board?"
At the time that HD made their miserable attempt at designing a Superbike EB was busy running his own company. HD did not become the majority share holder in Buell until shortly before they pulled out of Superbike racing. As talented as Erik Buell is he can't be in two places at once.
If and when Buell decides to build a race bike they will. Until then... well maybe you can find a Foggy cheap.
By the way. Maybe you don't really understand my take on the whole homologation thing. I don't like it. I think it penalizes small companies that would like to get into racing. The 3 million or so (150 bikes @ 20k each)that they are forced to spend on homo bikes could be better spent on R&D. After all what's the point forcing a company into building 150 bikes that are street legal only on some uninhabited island off the coast of Antarctica?
To the Big 4 homo bike budgets are pocket change.
Greg
|
Blake
| | Posted on Tuesday, May 27, 2003 - 06:18 pm: |
|
Ben,
Once again, lots of rhetoric. Still no answer to the question. All you blathering about what makes a better engine is purely opinion. As I've already recognized, your opinion is that more HP/CI equates to a better, more advanced engine. That is nothing more that your opinion and the result of what Japan Inc. has been sorking so hard to propagate. Which configuration achieves superior fuel economy?
My 100RWHP Cyclone gets better than 50mpg, even better if ridden conservatively. No 600cc IL4 with comparable power can come close to that. In my mind, simpler is better, and more efficient is better. If I can produce more power more simply and with better efficiency, and if maintenance requirements are minimized, is not my engine superior in many ways, maybe not all ways, but in many ways? Why give preference to other configurations simply because they have less displacement, yet comparable power? Why? Why not let all comparable powered sportbikes race in THE pre-eminent Superstock motorcycle racing series in America? Why... not... let... them... race?
Here are some more questions for you. If as you claim displacement is the only valid ruler for gaging performance, why does AMAPR offer displacement advantages to twin cylinder bikes in Superstock? Why, until this year did AMAPR offer displacement advantages to twins in Superbike? Why does WSB require intake restrictors on the four cylinder bikes and not the twins? Why are Moto GP bikes with fewer cylinders allowed lower minimum weights?
The answer for all the above is the same... Because there is more to gaging the performance of an engine than its displacement. If all the above are valid considerations to create equitable racing among differently configured machines, and I think I've shown that they are valid, why the hell doesn't AMAPR do the same?
Your point has just been proved invalid. Please answer the question. Why not let them race?
Bias in AMAPR is not corruption? 
Please consider the following... As a rules maker governing a racing organization claiming to promote fair and even competition and in writing even stating clearly that their rules are
quote:...designed to create a level playing field for all competitors...
how can a significant bias by a rules making body claiming to promote "a level playing field for all competitors" not constitute corruption? Answer... It absolutely does.
Why not let them race? One simple question, waiting for an honest answer. |
S320002
| | Posted on Tuesday, May 27, 2003 - 06:29 pm: |
|
Grndskpr,
"Didnt Buell do that in the begining(read RR1000)."
Nope. The RR1000 was not built for purposes of homologation. It was built because Erik had designed a really cool frame and Harley had 50 XR1000 engines sitting around in crates. Erik combined them. A few people looked at the result and decided it would make a really cool roadrace bike. A couple of years back a bunch of nuts got together and decided it would also make a great LSR bike. They were right. |
S320002
| | Posted on Tuesday, May 27, 2003 - 06:47 pm: |
|
re: Engine displacement as a criterion for determining race class. Wankel?
Yes, they have been used in motorcycles. |
Grndskpr
| | Posted on Tuesday, May 27, 2003 - 08:53 pm: |
|
"Didnt Buell do that in the begining(read RR1000)."
That should read:
"Didnt Buell do that in the begining(read RW750)."
Is that better S3???or was that not a 1(maybe 2) off bike
Roger
|
S320002
| | Posted on Tuesday, May 27, 2003 - 09:11 pm: |
|
Roger,
That should read:
"Didnt Buell do that in the begining(read RW750)."
Is that better S3???or was that not a 1(maybe 2) off bike
Nope. That doesn't work either. The RW750s (there were two of them) were built as pure race bikes and didn't require homologation.
Greg |
Davegess
| | Posted on Tuesday, May 27, 2003 - 11:12 pm: |
|
Erik had hopes that the RR1000 would be run in AMA Supperbike. He thought it could win Daytona. He needed I recall 50 bikes to do that.
It was built as a race bike first and a street bike second. A pretty good one at that winning twins races in England, France, US, Japan and New Zealand as the twins championship in New Zealand as well as the US amatuer twins title. (That US championship resulted in the first AMA rule change that one could argue was aimed at Buell. The lightweight twins class was dropped to 900 cc from 1000. this got rid of all the Ducatis around at that time also. In fact the change was propably aimed at keeping expensive exotic twins (an RR1000 was $15000 in 1986 money) out of the class and thus allowing regular people to race. |
Rocketman
| | Posted on Tuesday, May 27, 2003 - 11:39 pm: |
|
By the way. Maybe you don't really understand my take on the whole homologation thing. I don't like it. I think it penalizes small companies that would like to get into racing. Are you kidding? Which small companies are you talking about? The 3 million or so (150 bikes @ 20k each)that they are forced to spend on homo bikes could be better spent on R&D. After all what's the point forcing a company into building 150 bikes that are street legal only on some uninhabited island off the coast of Antarctica? That's an entirely misleading statement to make. The purpose of homologation is to ensure that you are racing a production bike because it's a production race. As for your comment regarding Antartica (are there any tracks there?) again you're misleading how strict homologation really is just because HD got away with cheating with its alleged VR assault on Poland. For sure Benelli were allowed some concessions with regard to production targets but the FP1 has had to go all the way. Incidentally, small in size the Foggy Team might well be but their financial clout is BIG and it was Foggarty who wanted to go in BIG but that's not to say that any other small company considering a likewise venture would have to spend as much as Foggy has. Foggy just can't stick getting beat. That's his excuse.
To the Big 4 homo bike budgets are pocket change. This is misleading also. The Japanese have suffered serious recession in recent years and their cutbacks in things motorcycle have been well documented. Witness the tie-up between Suzuki and Kawasaki. Kawasaki's parent company (KHI) have suffered serious financial setbacks and without the Suzuki merger, we might have lost Kwak bikes forever. For further proof of the Japanese motorcycle industry decline look at any race series in any country and you'll find the Japanese are not investing antywhere near what they use to. Take a look at Honda's efforts in Formula 1. It represents their stake perfectly IMO. If Honda could afford to be winning in F1 they would be, or they'd at least be close, but they ain't even that.
Rocket 
|
Blake
| | Posted on Wednesday, May 28, 2003 - 12:31 am: |
|
Rocket,
Your point might be valid if Superbike was a stock racing class. Is it really? I don't honestly think so. |
José_quiñones
| | Posted on Wednesday, May 28, 2003 - 07:56 am: |
|
quote:EB was busy running his own company.
Actually, EB designed and submitted a fuel in the frame chassis for the original VR1000, but HD did not choose it.
__________________________________________________
Homologation is what keeps privateers in the game.
The current AMA superbike rules have narrowed the gap between privateers and the factory efforts.
Check the qualifying times from last year compared to this year and the difference in qualifiying from the Pole to 20th place is smaller this year than before.
There is one particular privateer, a Buell employee, currently in the top 10 in AMA superbike points. How ironic.
Now back to supersport. Five manufacturers sell 600 cc fully faired streetbikes, and that's what they race.
Kawasaki went through the expense of fitting a slipper clutch, inverted forks and radial brakes on their new ZX6RR street bike so they could race it with those features.
Buell sells a 984cc naked bike, but wants to race a 1336cc ram air fully faired race bike against those 600's?
I thought you wanted "no special breaks", Blake?
If somebody wanted to race a Buell XB9R in Supersport, they could not race something like the ex ProThunder FUSA bike they are racing now, because they would have to comply with the following rules:
quote:1. Modifications from OEM
Only the modifications listed in this section are permitted. No other changes from showroom stock will be allowed.
2. Updating or Backdating
Absolutely no updating or backdating of parts will be allowed unless specified by the rules. Superseded or redesigned parts must be submitted to AMA Pro Racing for review and approval before use on applicable models in competition. In addition, these parts must be listed in the current OEM parts list as supplied to the AMA. The Approved Equipment List is available from the AMA Pro Racing office.
3. Homologation.
(a) Supersport and Superstock motorcycles require homologation. See Supersport and Superstock Approval.
quote:9. The following items may be replaced by aftermarket parts except as noted:
..
(f) Final drive sprockets and chains. Chain size may be changed.
(g) Rear shock (linkage must remain stock)
(h) Fairing and bodywork (not including fuel tank) may be replaced with cosmetic duplicates of the original parts.
(1) Size and dimensions must be the same as the original parts.
(2) Construction must be of plastic or fiberglass (no carbon or carbon composite fiber).
(3) Original combination instrument/fairing brackets may be replaced with aftermarket brackets of the same basic material. All other
fairing brackets must be original stock parts.
(4) Should the stock fairing include air-ducting tubes, those tubes may be removed. However, if used, the tubes must be original stock parts.
(5) See Fairing and Bodywork in General Equipment Standards.
The fairing and the ram air would be a problem, since the homologated street bike does not include these features.
quote:12. Carburetor/Fuel Injection/Intake modifications are limited to the following:
..
(f) All components involved in fuel injection systems must remain standard except electronic control modules, which can be modified or replaced
with aftermarket modules.
(1) Replacement modules must connect to original connectors.
(2) Installation of additional components to the fuel injection system is not permitted.
(3) Aftermarket modules must be available for immediate shipment from US warehouses to any of the manufacturer's US retail outlets for sale to the public. Availability must be maintained throughout the current racing season.
(4) Aftermarket modules must be priced no higher than the retail price of the original OEM module.
The current race ecm is not the same one in the publicly available "race kit"
quote:13. Engine/Ignition modifications are limited to the following:
(a) Except as noted, all internal and external engine parts must remain stock with no modifications, metal removal, blueprinting, or surface treatments.
(b) Pistons, rings, piston pins, and circlips may be replaced only with standard bore, stock production items. There is no allowance for
overbore.
(c) Cam sprockets may be slotted solely for the purpose of altering cam timing. Press-on cam sprockets may be replaced with aftermarket
steel bolt-on cam sprockets and adapters. Aftermarket cam chain tensioners are permitted.
(d) Cylinder head, cylinder and crankcase gasket surfaces only may be machined for increased compression. All other surfaces of the cylinder
head, cylinder and crankcases must remain absolutely stock, with no metal removal. Light cleaning of gasket surfaces with steel wool,
Scotch-Brite®, etc. is allowed.
(e) Cylinder head combustion chambers may be cleaned by bead blasting with valves seated in place. Intake and exhaust ports may not be
bead blasted or cleaned with abrasive material such as steel wool or Scotch-Brite®.
(f) Valves must remain as produced with no modifications. Valve springs may be shimmed with standard or aftermarket shims.
(g) Valve seat inserts may be reworked or replaced with OEM or aftermarket
seats of original dimensions. Any dimensional thickness of the stock inserts may not be increased. Aluminum casting of cylinder
head ports and combustion chambers must remain absolutely stock, with no metal removal.
The Hals or Kosco Buell XB9R would look very different than what it currently looks like if it was held to the same standard as the rest of the bikes in the AMA Supersport class.
Is that what you want?
|
José_quiñones
| | Posted on Wednesday, May 28, 2003 - 08:02 am: |
|
The AMA Homologation rules:
quote:2. Approval of Motorcycles
(a) Homologation procedure information is available from the AMA Pro Racing office.
(b) Approval is not required for 250 Grand Prix or Superstock twincylindermotorcycles.
(c) Approval of Superbikes - 750cc Four Cylinders, 900cc Three Cylinders and 1000cc Twin cylinders
(1) Only approved motorcycles may be used in Superbike competition.
The AMA will only review applications for homologation from motorcycle manufacturers or their distributors. Homologation applications
and procedures are available through the AMA Pro Racing home office.
(2) Once a motorcycle has been approved, it may be used until such time that it may be disqualified by new rules or rule changes.
(3) Compliance with homologation requirements will not guarantee AMA approval. Homologation may be withheld or withdrawn for any reason the AMA deems in the best interest of Superbike
competition.
(4) 750cc four-cylinder, 900cc three-cylinder and 1000cc twin cylinder motorcycles must be street certified in an FIM-recognized country
and available through US distributors or retail dealers. A list of eligible motorcycle models is available from the AMA Pro Racing home office. Minimum import requirement is as follows:
All manufacturers – 50 units
(d) Approval of Superbikes - 1000cc Multi-cylinders
(1) Only approved motorcycles may be used in Superbike competition.
The AMA will only review applications for homologation from motorcycle manufacturers or their distributors. Homologation applications
and procedures are available through the AMA Pro Racing home office.
(2) Once a motorcycle has been approved, it may be used until such time that it may be disqualified by new rules or rule changes.
(3) Compliance with homologation requirements will not guarantee AMA approval. Homologation may be withheld or withdrawn for any reason the AMA deems in the best interest of Superbike
competition.
(4) 1000cc multi-cylinder motorcycles must be street-certified in the US and available through US retail dealers. A list of eligible motorcycle
models is available from the AMA Pro Racing home office.
Minimum import requirements are as follows:
Manufacturers with 200 or fewer US retail dealers – 300 units
Manufacturers with more than 200 US retail dealers – 400 units
(e) Approval of Supersport and Superstock Motorcycles
(1) Only approved motorcycles may be used in Supersport and Superstock competition. Twin cylinder motorcycles will be exempt
from homologation when competing in Superstock. The AMA will only review applications for homologation from motorcycle manufacturers
or their distributors.
(f) Approval of Formula Xtreme® Motorcycles
(1) Homologation is not required.
(2) Formula Xtreme competition is restricted to motorcycles (engines and frames) produced for US street use and available in the US through retail dealers. A list of eligible motorcycles is available from AMA Pro Racing.
|
Benm2
| | Posted on Wednesday, May 28, 2003 - 08:30 am: |
|
quote:Once again, lots of rhetoric. Still no answer to the question. All you blathering about what makes a better engine is purely opinion. As I've already recognized, your opinion is that more HP/CI equates to a better, more advanced engine. That is nothing more that your opinion and the result of what Japan Inc. has been sorking so hard to propagate. Which configuration achieves superior fuel economy?
Blathering? Rhetoric? Is that the assessment for those that disagree with you? If you believe that what I wrote regarding engine configurations is “blathering rhetoric” then show me the ENGINEERING DOCUMENTATION that disputes it. As engine manufacturers around the world build smaller, higher powered, engines (Honda, Mazda, Suzuki, Ford, Daimler-Chrysler, GM, Hyundai, Toyota, BMW, VW, Renault, etc.) that use overhead cams & multiple valve configurations, you attest that this is due to worldwide brainwashing by the Japanese. Honda makes automobiles that get over 60-mpg. What size & engine configuration is used in those engines? Diesel engines are noted to get better mileage than SI engines, what sort of configurations are being used in those new engines?
quote:My 100RWHP Cyclone gets better than 50mpg, even better if ridden conservatively. No 600cc IL4 with comparable power can come close to that. In my mind, simpler is better, and more efficient is better. If I can produce more power more simply and with better efficiency, and if maintenance requirements are minimized, is not my engine superior in many ways, maybe not all ways, but in many ways? Why give preference to other configurations simply because they have less displacement, yet comparable power? Why? Why not let all comparable powered sportbikes race in THE pre-eminent Superstock motorcycle racing series in America? Why... not... let... them... race?
Which engine weighs more? Yes, we’ve all established that a large displacement twin with hydraulic valve adjusters may be a better street engine. Which is a better race engine? Who’s engines suffer more DNF’s? Are you honestly purporting that a 100RWHP Buell will be more reliable than a stock CBR600RR? If you’re sole goal in purchasing a motorcycle was reliability, would you have really chosen a Buell? Do stock, street reliability & maintenance concerns matter worth a darn on the racetrack? There is NOT a preference for smaller engines, there is a class limit that’s been established since 1987. Why does an SV650 weigh so much less than an XB9R? Your argument that all sportbikes of similar power should be classed together is fragile also. Even ONLY looking at current-year models, there are offerings from many manufacturers that could, by your rules, race in supersport (or superstock).
Supersport racing is business. The money to pay Tommy Hayden comes from somewhere, perhaps the sales of ZX6R’s? The Japanese have invested heavily in AMAPR, and have supported the series for years. If… Buell… wants… to… compete… then… they… will… build… a… competitive… bike.
quote:Here are some more questions for you. If as you claim displacement is the only valid ruler for gaging performance, why does AMAPR offer displacement advantages to twin cylinder bikes in Superstock? Why, until this year did AMAPR offer displacement advantages to twins in Superbike? Why does WSB require intake restrictors on the four cylinder bikes and not the twins? Why are Moto GP bikes with fewer cylinders allowed lower minimum weights?
The offset for twins was based on a theoretical calculation regarding piston speed. This, too, was flawed, as proven by the dominance of the Ducati’s and the RC51. The language in the CURRENT superstock rules are a CONCESSION to Buell. Have they taken advantage of it? Does MotoGP allow lower weights for the use of pushrods & two valve heads? Even with the lower weight allowance, do you see any twins in MotoGP? How well is the triple doing? How about the fours?
quote:The answer for all the above is the same... Because there is more to gauging the performance of an engine than its displacement. If all the above are valid considerations to create equitable racing among differently configured machines, and I think I've shown that they are valid, why the hell doesn't AMAPR do the same? Your point has just been proved invalid. Please answer the question. Why not let them race??
Where in your rant have you proven anything invalid? They CAN race, in superstock, free of restrictions. Where are they?
quote:Why not let them race? One simple question, waiting for an honest answer.
Please rephrase your question. You have no intention of waiting for an honest answer. You’ve been given many of them, and you ignore them, or produce invective that flatly insults, and questions peoples integrity, patriotism, and business integrity.
|
Reepicheep
| | Posted on Wednesday, May 28, 2003 - 08:54 am: |
|
I am admittedly a rookie at the whole race thing here, but I believe that the RC-51 and Ducatti dominance was not a result of the displacement allowance of the twins.
Take any of the other competitive inline fours and add desmo valving and similar oversquare pistion dimensions, and I think that four would have been every bit as competitive as the Duc's, and would probably mop up the field (as the new 4 cyl Ducatti is suggesting it might).
Take any of the other competitive inline fours and add as much money and expertise (engineering and rider) as Honda did to the RC-51, and I think that four would be just as competitive as the RC-51.
I don't think a downward displacement adjustment for desmo valving makes any less sense then an upward adjustment for pushrods (all relative to OHC). I think we agree. Ducatti slipped through a loophole (which is all a part of racing, more power to them) because of the desmo drive train, not because they are a twin.
The inline four makers are free to implement desmo valve trains if they want too... why give them a "special" advantage 
|
Blake
| | Posted on Wednesday, May 28, 2003 - 11:07 am: |
|
JQ, Ben,
More skirting the issue. <yawn> Why not answer the simple question with a simple answer?
JQ,
Who said anything about letting Buell race a Pro Thunder spec bike in Supersport? That would be wrong. Why not allow comparably powered sport bikes race in AMAPR Supersport?
It's a very simple question. It's answer doesn't require a regurgitation of the rulebook or a treatise on engine performance parameters. Just give me a simple answer. If as Merrill Vanderslice claims in writing, that the AMAPR rules are "...designed to create a level playing field for all competitors..." and there exists competitors wanting to race Ducati 749RS machines in Supersport, why not let them race? It's a simple question deserving a simple honest answer.
Ben,
Sorry if you take offense to my rebuttal. No personal attack was or is intended. But Ben, did you answer the question? You seem to think so. I don't see it. I see a lot of excuses and some false logic. On one hand you seem to be refuting that four cylinder machines make more power than comparably configured/sized two cylinder machines, then you point out that the machines in GP with more cylinders are doing better despite their weight penalty.
I fully agree that the liter twins were dominant in AMAPR and World Superbike and that a rules adjustment was needed to allow the fours to regain competitive parity. This even though out of the last four years a 750cc IL4 won three of the AMAPR Superbike titles.  Most reasonable people in the business believed that upping the four cylinder displacement to 800cc's was the fair thing to do. AMAPR however saw fit to boost it by 33% to equal that of two cylinder machines. Granted, there may be good reasons other than racing parity to do so, I agree. But if that is the case, how fair is it to the competitors racing the twins? Why not grant a comparable displacement increase to twin and triple cylinder machines? Why in one fell swoop render them uncompetitive? Why exclude them from Supersport? That is what AMAPR has done and such actions directly conflict with AMAPR's stated policy and the common sense of any fair minded person.
Why not let them race?
If you did honestly answer that question and I just didn't see it, how about giving me the reader's digest version?
In a rules making body tasked with maintaining parity among all competitors, bias = corruption. It's that simple.
|
S320002
| | Posted on Wednesday, May 28, 2003 - 12:04 pm: |
|
Hmmm...
(2) Once a motorcycle has been approved, it may be used until such time that it may be disqualified by new rules or rule changes.
(3) Compliance with homologation requirements will not guarantee AMA approval. Homologation may be
withheld or withdrawn for any reason the AMA deems in the best interest of Superbike competition.
Those sound like a carefully phrased statements for "we're allowed to change the rules in the middle of the game if we don't like the score".
Greg |
Mikej
| | Posted on Wednesday, May 28, 2003 - 12:08 pm: |
|
Probably in the middle of a race if they wanted to deal with the aftermath. |
S320002
| | Posted on Wednesday, May 28, 2003 - 01:28 pm: |
|
Rocket,
"Are you kidding? Which small companies are you talking about?"
Tularis here in the US would be one example. AMAPR rules keep the Big Boys safe from the upstarts.
"As for your comment regarding Antartica (are there any tracks there?) again you're misleading how strict homologation really is just because HD got away with cheating with its alleged VR assault on Poland. For sure Benelli were allowed some concessions with regard to production targets but the FP1 has had to go all the way."
Regarding Antarctic tracks, they are not required for homologation purposes. Roads however may be. I'm curious. Have you ever heard the word facetious?
As I recall the rules said the VR1000 had to be street legal somewhere in the world, HD picked Poland. How was that cheating? I don't imagine Foggy Pet had much trouble getting declared legal in Maylasia either.
"To the Big 4 homo bike budgets are pocket change." "This is misleading also..."
Are you kidding??? Honda is a multi-billion dollar corporation and has budgeted more than $150 million for their RCV GP bike alone. As to the cooperation between Kawasaki and Suzuki, according to their own claims, it does not include any of their sportbikes.
Greg |
Blake
| | Posted on Wednesday, May 28, 2003 - 01:42 pm: |
|
Reep,
How is a desmodromic valve train superior to an OHC with springs valvetrain? AMAPR makes no distinction between the two anywhere. The VTR1000SP (RC51 racebike) has proved itself just as capable as the Duc 998RS. Don't get me wrong, I think desmo is too cool! If someone could figure out how to combine desmodromics with hydraulics for zero valvetrain maintenance that would be even better. |
Benm2
| | Posted on Wednesday, May 28, 2003 - 02:02 pm: |
|
Desmo uses less power than spring valvetrain. Friction losses as spring pressure increases as the valve is opened are not recovered. |
Grndskpr
| | Posted on Wednesday, May 28, 2003 - 03:33 pm: |
|
AMAPR however saw fit to boost it by 33% to equal that of two cylinder machines. Granted, there may be good reasons other than racing parity to do so, I agree. But if that is the case, how fair is it to the competitors racing the twins?
How is Ducati doing at WSBK this year with the same rules???
Roger |
Blake
| | Posted on Wednesday, May 28, 2003 - 03:37 pm: |
|
How much less? Desmo also must close the valve. If desmodromic valve actuation yielded any significant power advantage, why isn't it used in Formula 1? I don't see it. |
Reepicheep
| | Posted on Wednesday, May 28, 2003 - 03:52 pm: |
|
My understanding was that spring loaded valve trains will have a maximum frequency that can be achieved that is lower then the maximum operating frequency (RPM) of gear driven valve trains. I thought it was something to do with the springs needing to get so strong to get the valves back onto the cams that the cam surface would not survive. But I could be mistaken, it is a dim memory of something I read.
I thought that was one of the reason the Desmo twins were closer to the performance numbers of the fours.
But even if that is true, the maximum frequency of the valves on an inline four may not be the current bottleneck, so it may be a future opportunity as other rpm limiting items are eliminated, not a current one.
Don't the formula one guys us pneumatic valves? Which are closer to desmo's then OHC spring loaded valves.
|
Smadd
| | Posted on Wednesday, May 28, 2003 - 04:01 pm: |
|
"How is Ducati doing at WSBK this year with the same rules??? "
Other than displacement, I don't think the rules are the same. I believe WSBK has the 1000 IL4's fitted with air restrictor plates. Ducati should fare much better there. |
Benm2
| | Posted on Wednesday, May 28, 2003 - 04:42 pm: |
|
When desmo closes the valve, its only fighting valve inertia. In a spring system, the cam fights the spring open, and the friction load on the valve bucket increases as the lift (and spring deflection) increase. To close, the spring will APPLY torque to the cam, but again the friction between the lobe & bucket will be lost. Plus, the friction losses from spring systems start high, as the returning forces need to be adequate at peak rpm. Desmo systems "autmatically" adjust the force required to move the valve as rpm increases, because its really only fighting inertia. Think about which cam you could turn by hand.
Plus the spring freak-out factor (natural frequency thing) limits springs also, and damping (like nested springs) produces heat & additional losses. If I remember correctly, pneumatic springs don't have natural frequencies. (probably remembering wrong, long time ago in universe far away) Plus, a pneumatic spring has very little mass. |
Blake
| | Posted on Wednesday, May 28, 2003 - 05:02 pm: |
|
Reep,
The RC51 was neck and neck with the Ducati 998RS last year in WSB. It won the championship and with the Duc being piloted by one hell of a racer. There are no gears in a desmo valvetrain. The over head cams of a desmo valvetrain are driven by belt or chain just like a conventional OHC valvetrain.
Pneumatic return valvetrains simply use gas charged cylinders as springs instead of metalic coil springs. The pneumatic springs do away with the mass of the steel springs and so are beneficial at stratospheric engine speeds. Pneumatic return valvetrains use cams just like spring return valvetrains. Interesting stuff, but not a significant advantage for Ducati over the RC51.
WSB=Ducati Cup + Foggy Petronas Triple. There are no other factory teams competing. |
Blake
| | Posted on Wednesday, May 28, 2003 - 05:12 pm: |
|
Ben,
You seem to think the force required to close a valve at 15K rpm is insignificant. It is about the same as the force required to compress a valve spring that is designed to start floating at just over 15K rpm.
Frictional losses at the cam/follower are relative to the viscous lubrication film thickness, the oil's viscosity, and the sliding speed of the cam and follower. Force does not directly enter the equation. |
|
AMA Pro Racing Seeks to Please Japanese Benefactors 
»
Archive through May 28, 2003