MotoGP - Discutii tehnice

[PzKpfW]

1 hour ago, prafrau said:

nu prea inteleg avantajul flexibilitatii prinderii de bloc cand aia pare o componenta turnata (spre deosebire de aluminiu unde e forjata) si apoi sudata de restul cadrului (ca la aluminiu)

cnc-ul va lucra mai rapid ca matriterul, sudura in aluminiu nu mai e ceva asa de exotic

Faptul că este alcătuit din segmente distincte îi ajută să varieze mai ușor designul, geometria și rigiditatea.
 

“The design develops more and more and the more you know your targets, not just in term of global stiffness but also in terms of local stiffness, then the more complex the parts become. Your cross-section may be the same everywhere but you can tailor the thickness of the tubing to meet your targets.” - Sebastian Risse, KTM RC16 project leader.

 

Apoi este aspectul rapidității și costului realizării unor modele de test: este mai simplu, mai rapid și mai ieftin să sudezi niște bare de metal între ele decât să frezezi un întreg ansamblu dintr-un bloc de aluminiu. La aluminiu, partea centrală a șasiului este monobloc, de la jug până la montanți.

 

 

Faptul că au pierdut concesiile nu prea contează. Tot le va fi mai ușor să producă x variante ale unui design și să le testeze fizic față de cei care folosesc șasiuri monobloc. Mai mult, KTM folosesc acest gen de cadru la toate motocicletele pe care le produc. Pe partea asta sunt deci ajutați de experiență și pot ulterior să transfere mai ușor pe stradă ceea ce funcționează pe circuit. Și nu este o exagerare - exemplu concret, că tot vorbeam dincolo de Ducati: observă similaritatea dintre cadrul de Desmosedici și cel care a ajuns (10-15 ani mai târziu) pe o motocicletă de stradă:

 

Deci nu, nu cred că este doar fiță sau dorința de a fi diferit.

*Nu sunt inginer designer în MotoGP, asta înțeleg și eu din ce explică alții cu mai multe cunoștințe și acces mai facil la informații.

Editat Iunie 21, 2021 de PzKpfW

[prafrau]

Acum 22 minute, PzKpfW a spus:

Faptul că au pierdut concesiile nu prea contează. Tot le va fi mai ușor să producă x variante ale unui design și să le testeze fizic față de cei care folosesc șasiuri monobloc. Mai mult, KTM folosesc acest gen de cadru la toate motocicletele pe care le produc. Pe partea asta sunt deci ajutați de experiență și pot ulterior să transfere mai ușor pe stradă ceea ce funcționează pe circuit.

 

daca au pierdut concesiile au pierdut testele nelimitate, anul asta parca sunt doar 3 teste

 

din ce spui tu ei fac opusul exemplului ducati, transfera din cunostintele de pe strada la curse

ar cam trebui sa fie invers, sa inceapa si ei sa faca cadrele alea de strada de aluminiu pentru 1-2 kg in minus folosind experienta din motogp

poate scap si eu de vopsit mereu orice zgarietura de pe cadru ca sa nu rugineasca

Editat Iunie 21, 2021 de prafrau

[PzKpfW]

3 minutes ago, prafrau said:

daca au pierdut concesiile au pierdut testele nelimitate, anul asta parca sunt doar 3 teste

Corect. Dar pot să vină la teste cu 5 versiuni de cadru dacă vor. Celorlalți le-ar fi mai greu.

 

3 minutes ago, prafrau said:

din ce spui tu ei fac opusul exemplului ducati, transfera din cunostintele de pe strada la curse

Transferă dintre spre stradă/competiții offroad cunoștințele legate de tehnica de fabricarea cadrului. Pe circuit rafinează designul. Și Ducati a făcut la fel: când au intrat în MotoGP în 2003 toate motocicletele pe care le fabricau aveau cadru din oțel tubular. Și toate motor V2/L2 - dealtfel și motorul în 2 pistoane au vrut să-l bage la MGP, dar asta e altă poveste.

[PzKpfW]

 

[Method]

Foarte interesant dar e cam vechiut cred nu?

Acum parca fac (si ei) capacul chiulasei din cf.

F misto arata galeriile,superba sudura.Equal lenghth nu ca la noi pe strada

[PzKpfW]

Nu cunosc anul, dar nu cred că e foarte recent: clipul e din 2018, iar motorul are cel mai probabil câțiva ani în plus. Totuși, având în vedere cât de rare sunt pozele cu motocicletele de GP doar fără carene, să vezi motorul în sine expus e chiar raritate.

 

Cred că la galerii contează fluxul (și deci raportul lungime/diametru) nu neapărat lungimea în sine. În fine, e oricum mai simplu cu evacuarea la 4 în linie față de V4 (în afară de interferența la nivelul colectorului final).

 

După îndelungi așteptări - Rear ride height device ready for Suzuki in Styria.

[Method]

La 03.08.2021 la 15:18, PzKpfW a spus:

Nu cunosc anul, dar nu cred că e foarte recent: clipul e din 2018, iar motorul are cel mai probabil câțiva ani în plus. Totuși, având în vedere cât de rare sunt pozele cu motocicletele de GP doar fără carene, să vezi motorul în sine expus e chiar raritate.

 

Cred că la galerii contează fluxul (și deci raportul lungime/diametru) nu neapărat lungimea în sine. În fine, e oricum mai simplu cu evacuarea la 4 în linie față de V4 (în afară de interferența la nivelul colectorului final).

 

După îndelungi așteptări - Rear ride height device ready for Suzuki in Styria.

Da,adevarul ca nu prea le expun...ceea ce e si normal.

Nu,eu vorbeam de faptul ca le-au facut de lungimi egale pt toti cilindrii tocmai pt a nu se intretaia gazele de la un cilindru cu celalat,spre deosebire de strada unde nu sunt deloc de lungimi egale.Ok,nu conteaza pt strada,e un detaliu prea fin pt a face diferenta in productia de serie,dar in racing e lege.

 

Suzuki e departe de Honda/Ducati/Yamaha ca si tehnica si bani investiti.Si asta se vede.Pacat de Mir.

[xt600]

Acum 6 ore, Method a spus:

 

Suzuki e departe de Honda/Ducati/Yamaha ca si tehnica.... 

Pe ce te bazezi cand spui asta? Ai ceva informatii din surse ce pot fi accesate sau este o simpla presupunere? 

[PzKpfW]

Sunt ultimii care au venit cu sistemul de control al suspensiei, singurii care nu au basculă de carbon, Mir spunea acum 2 luni că motocicleta este practic la fel ca cea de anul trecut (i.e. dezvoltare 0) și citeam la un moment dat (nu mai găsesc sursa) că au cea mai puțin numeroasă echipă de uzină. Cred că e destul de clar.

[Method]

Nu as fi putut sa raspund mai bine

e destul de clar.

[xt600]

La 05.08.2021 la 17:26, PzKpfW a spus:

Sunt ultimii care au venit cu sistemul de control al suspensiei, singurii care nu au basculă de carbon, Mir spunea acum 2 luni că motocicleta este practic la fel ca cea de anul trecut (i.e. dezvoltare 0) și citeam la un moment dat (nu mai găsesc sursa) că au cea mai puțin numeroasă echipă de uzină. Cred că e destul de clar.

Deci daca motoreta nu are bascula de carbon si holeshot, este departe, ca tehnica, de ceilalti. Inteleg de aici ca nu conteaza in ecuatie ca au unul dintre cele mai bune frame-uri din competitie, un motor F BUN, cu mult potential, etc. Credeam ca vii cu vreun link la o analiza pertinenta a unuia care cunoaste situatia din interior, care stie exact tehnologia din spatele acelei motociclete. Vezi sa nu cazi in eroarea colegului @Method, care considera ca daca nu ai sasiu, bascula, furca, etc din carbon, esti pe undeva prin epoca pietrei. 

Deocamdata vad ca Mir si Rins stau bine in clasamentul FP3 cu motoreta asta "departe de Honda/Ducati/Yamaha ca si tehnica"..  

[PzKpfW]

La nivel tehnic există elemente convergente care sunt adoptate de către toți. În principiu asta presupune că sunt performante. Suzuki investește puțin (probabil cel mai puțin dintre constructorii implicați). Performanțele lor sunt mediocre (de jumătatea clasamentului) și nedemne de niște campioni en-titre. Ceea ce spui tu poate fi adevărat (deși nu văd nicio sursă citată), dar este total irelevant: au performanțe slabe, iar pilotul lor campion se plânge de lipsa de dezvoltare.

[PzKpfW]

 

Motorul KTM de sezonul trecut (!)

 

   

 

Nu am idee cum a primit aprobare pentru a fi expus. Foarte interesant cum filosofia lor (unică din câte știu) cu două filtre de ulei mici (în loc de unul singur mai mare) s-a transpus și în MotoGP. Interesant și unghiul de 86 de grade între bancuri - nimeni nu mai folosește așa ceva.

 

Pentru o clarificare finală în ceea ce privește șasiul cu grinzi din oțel tubular pe care-l folosesc (tot iterația 2020):

 

  

[xt600]

https://www.motorsportmagazine.com/articles/motorcycles/motogp/we-build-our-motogp-engine-so-the-electronics-have-to-do-as-little-work-as-possible

Acum 20 minute, xt600 a spus:

https://www.motorsportmagazine.com/articles/motorcycles/motogp/we-build-our-motogp-engine-so-the-electronics-have-to-do-as-little-work-as-possible

Legat de discutia despre bugetele echipelor, nenea asta confirma ceea ce spuneam eu, nu neaparat bugetele sunt mai mari la KTM sau (poate) Ducati, ci modul in care sunt alocate fondurile si cheltuiti banii: mult mai rapid si fara multa birocratie.

"KTM seems able to overcome problems quicker than any other factory in MotoGP, why is this?

 

I think our big advantage is that decisions are taken very quickly. If I or someone else has a problem we go to Pit [Beirer, KTM’s motorsport director], ask for some money to fix it and we get the money. In other companies, as far as I know them, there are decision processes that take longer, which slows everything down, which makes a big difference.

This doesn’t mean that we have an unlimited budget – that’s clearly not the case – but if there’s an emergency and we can show that we have a solution then normally we can react quite quickly. That’s the difference between us and other companies."

[ioio_viola]

‘We build our MotoGP engine so the electronics have to do as little work as possible’

 

Kurt Trieb designed the engine of KTM’s RC16, which has won as many races as Ducati’s Desmosedici over the past season and a half. Trieb tells us about his design philosophies and reveals that the RC16 isn’t a 90-degree V4

 

KTM entered MotoGP four years ago and is already battling with rival manufacturers who have been racing in the premier class for decades. Only Yamaha has won more races since the start of 2020, with KTM’s five victories equalling Ducati’s win rate and bettering that of Aprilia, Honda and Suzuki.

At the heart of KTM’s RC16 is its engine, the same 1000cc 90-degree V4 configuration used in Ducati’s Desmosedici, Honda’s RC213V and Aprilia’s RS-GP. At least, that’s what we always thought. Except that our recent chat with KTM’s Head of Engine Development Road Racing Kurt Trieb revealed that the RC16 isn’t a 90-degree V4, after all.

There’s no doubt that Trieb – who also designed KTM’s Moto3 250cc single and its original 2005 MotoGP V4 (used briefly by Team Roberts) – has played a huge part in the RC16’s success, from his original concept to detail work on firing configurations, combustion and so on.

 

Nowadays electronics take up more time than any other aspect of machine performance in MotoGP garages, but Trieb quickly realised the importance of creating an engine that doesn’t require too much interference from the various electronic rider controls, which all slow the bike down, rather than speed it up.

 

You used to engineer Formula 1 car engines, which are all about maximum horsepower, whereas MotoGP bikes are mostly about part-throttle, does that make the job more interesting – chasing a friendly engine instead of big numbers?

My background is automotive and automotive motor sport – engine design in Formula 1 and touring cars. The biggest difference in motorcycles is that you have the clutch and gearbox to think about. In car racing you don’t worry about that stuff, so that’s a big difference in MotoGP.

And, yes, in MotoGP the engines are used from 8000rpm to 18,500rpm. That’s a big difference from an F1 engine, where in my time there, the engine was always working above 12,000rpm. That’s something you cannot do in motorcycles.

What’s your speciality – engine architecture, combustion design or what?

It’s everything. From the start of the RC16 project it was very important to have a reliable and simple base which works, so you can go testing and develop your own package.

 

What’s most important when you’re trying to make an engine work effectively on part throttle?

Internally, it’s basically the gas exchange [the cycle of supplying fresh air and removing exhaust gases] which you have to set up correctly. That’s port design, turbulence inside the cylinder and so on.

Everything has to work together. If you have a port that gives good flow figures that doesn’t necessarily mean you’ll have better combustion. Let’s say the combustion could be bad at low throttle or at low engine speed, even if the port flows well, so it’s all a bit of a compromise and a combination.

What’s the difference between an F1 cylinder and a MotoGP cylinder?

Formula 1 has much shorter-stroke engines, whereas in MotoGP we are limited by the 81mm bore restriction, so I think we are racing long-stroke engines!

Can short-stroke engines be too revvy, too peaky for bikes?

I must say I’ve always been a fan of short-stroke engines. I think you can make them work well, especially if you get the port design and valve lift correct, because this can compensate for some of the benefits you get from longer stroke engines.

In MotoGP the acceleration limit until you reach fifth and sixth gears is grip and wheelie, not horsepower. How does that affect your work, or do you leave that to your electronics and downforce people?

Let’s say that in the first four gears of a MotoGP bike normally you cut the power with the electronics. From 2019 to 2020 we made a good step with our engine, by adjusting the power delivery to what the rider can naturally use on track, so that the electronics have to do as little work as possible.

So you designed an engine that doesn’t need electronics so much?

We still need electronics, that is clear, but let’s say we’re now working more in that direction.

Since Michelin returned to MotoGP the back tyre has become a crucial part of stopping the bike, so negative torque is very important. So when you design an engine do you think about getting the bike into corners as well as out of them?

You need negative torque to stop the bike, that’s clear. What we’ve learned is that you need an engine that burns consistently at very low throttle openings. If you close the throttle completely the engine will shut off and there’s a fine line where you can still keep the engine burning and also deliver some negative torque for engine braking. For the rider it’s very important to have a consistent feeling in this area of corner entry – because if the engine shuts off and cuts in again it’s a disaster.

 

Some factories use an adjustable exhaust valve in the exhaust to modulate negative torque. What about you?

We have tested these but they never rated as a must-have. As I said, if you have an engine that doesn’t burn at very low throttle openings then you have a problem. If this is the case an exhaust valve allows you to create back torque with the throttle, so it’s a workaround.

So if you do your work right inside the engine you don’t need one?

Yes.

How many different firing configurations have you used since the beginning of the RC16 project while trying to find the best irregular firing from the engine?

We are now on our third version of the firing order. First we had the screamer, then the big bang and now we have the long bang, or whatever you want to call it. In the end it’s an irregular firing order across the cylinder bank, so you don’t have constant pulses going to the rear tyre, you have inconsistent pulses.

What does this offer? People have talked about this for years…

I don’t think there’s any fixed explanation, so I can only tell you what I think. I think it’s related to the frequencies and the gas exchange, with the irregular firing configuration translating well to the rear tyre.

 

If you have a screamer engine with two cylinders firing together then everything happens at higher frequencies. I compare a screamer to a two-stroke – when you keep the throttle constant and the exhaust starts working then the engine revs go up without you changing the throttle position. This is exactly what you don’t want and this is what happens with a screamer.

That’s my understanding, so at very low throttle openings or at very low differences you have quite a reaction from the engine and this is what the rider cannot handle. I think that’s the biggest difference.

When Yamaha introduced its first big-bang MotoGP engine in 2004 its engineers had some unusual theories about why big-bang engines work. What are your thoughts?

With the Yamaha and Suzuki [inline-four] engines it’s another story. It’s related to the irregularity of the crankshaft movement. For instance, when a cylinder is in the compression stroke you have deceleration and after ignition you start to accelerate again and this gives you variations in crankshaft speed. With the type of crankshafts that Yamaha and Suzuki use they get a better regularity of crankshaft rotation.

 

Why did you choose to build a V4?

Very simple – power! – because you don’t have to compromise the inlet and exhaust ports. Another aspect for us was that with these high-revving engines the longer the crankshaft and the camshafts the more problems you get with torsional and bending vibration.

As I said before it was important for us to have a reliable mechanical base. This is achievable with an inline-four, no question, but it requires more development effort.

Was choosing a 90-degree vee angle the obvious way to go?

In fact we have slightly less, 86 degrees. That was decided at the beginning of the project, due to packaging considerations. We didn’t want to have a balance shaft, and 86 degrees is the limit for getting away without a balance shaft.

 

Honda has a 90-degree vee and if I was making our engine today I’d probably make a 90-degree vee, but it’s not a big deal, it doesn’t make a big difference.

Does the RC16 use an outside flywheel, like Ducati’s Desmosedici, so you can adjust crankshaft inertia?

We only have a small alternator at one end of the crankshaft. In our engine we get crankshaft inertia from the crank webs.

Isn’t useful to be able to adjust crankshaft inertia, according to the rider’s request?

We’ve had many big discussions about what’s the correct inertia but we’ve been something in the same range for the last two or three years. And from what I’ve seen from our competitors they’re not much different. We’re all in the same range, let’s say.

What’s the difference between your Moto3 and MotoGP cylinders?

The valve size and valve angle aren’t so different. The main thing is the ports, valve lift and cam profile, because Moto3 engine rpm is limited in the rules, so the engines run at lower speeds [13,500rpm maximum].

The four-stroke engine has been developed for more than 130 years, what will be the next steps? Surely any gains now must be tiny?

Yes, but surprisingly there are gains. It’s always an ongoing development and even if you’re only making small steps they can be significant.

 

There’s talk of MotoGP moving to so-called carbon-neutral fuels in the not-too-distant future, what are your thoughts?

From what I’ve heard we are talking about two different things.

The first is bio-fuel with 20% ethanol, which doesn’t make a big difference from an engine point of view, so that would be relatively easy to do.

The second is synthetic fuel, in which you use hydrogen and mix it with carbon dioxide, and this is another story. I don’t have any experience with this kind of fuel but from what I hear the knock limit [a critical point in the combustion process] and octane numbers are much lower, so you have to accept lower performance from the engine. Or you can add some additives to fix this problem.

I think this is what F1 is doing now, so there’s development ongoing and they’ve committed to use this fuel from 2025, so I think MotoGP will follow this way. Developing a new combustion process is a big development task, a big challenge. In the motorcycle industry we don’t have the same resources to do this that they have in the auto industry.

But to be honest, motor sport will never be good for the environment – that’s how it is.

If synthetic fuels reduce performance this would surely be a good thing for MotoGP, with the bikes now reaching 225mph/360kph?

Yes, I agree that the speeds we are seeing are getting too high.

Next year all MotoGP factories will be allowed to have new-spec engines for the first time since the start of 2020, so presumably the bikes will be even faster?

Yes, I expect all out competitors to make more steps. Our own priority is more power! Ducati still sets the benchmark in this area and you can see weekend after weekend where their advantage is – if you can overtake on the straight it can change your race completely.

If you have good acceleration and top speed then it’s time for free, because the rider doesn’t have to take risks to gain that time. We want to draft and get alongside the Ducati – we are all in the same boat!

KTM seems able to overcome problems quicker than any other factory in MotoGP, why is this?

I think our big advantage is that decisions are taken very quickly. If I or someone else has a problem we go to Pit [Beirer, KTM’s motorsport director], ask for some money to fix it and we get the money. In other companies, as far as I know them, there are decision processes that take longer, which slows everything down, which makes a big difference.

This doesn’t mean that we have an unlimited budget – that’s clearly not the case – but if there’s an emergency and we can show that we have a solution then normally we can react quite quickly. That’s the difference between us and other companies.

[xt600]

Un articol de citit... : https://www.motorsportmagazine.com/articles/motorcycles/motogp/will-f1-tyre-cooling-wheel-rims-soon-feature-on-motogp-bikes

 

Si inca unul: https://www.crash.net/motogp/feature/987287/1/espargaro-prefers-manual-over-automatic-aprilia-rideheight-system

[PzKpfW]

[Method]

De ce are 4 ?

[Kagemusha]

În afară de ambreiaj și frână o avea una pentru fiecare holeshot: față/spate?

[PzKpfW]

Exact. Ambreiaj (maneta principală), frână spate (în fața ambreiajului), holeshot (maneta mică), squat (pentru suspensia spate, clapa de lângă manșon).

 

E mai puțin dramatic decât pare: ambreiajul și holeshot-ul le folosește doar la start.

[ENEOS]

Aprilia? 

[PzKpfW]

Mai precis, RS-GP-ul lui Viñales.

[Method]

La 14.10.2021 la 11:18, PzKpfW a spus:

Exact. Ambreiaj (maneta principală), frână spate (în fața ambreiajului), holeshot (maneta mică), squat (pentru suspensia spate, clapa de lângă manșon).

 

E mai puțin dramatic decât pare: ambreiajul și holeshot-ul le folosește doar la start.

Dar nu ziceau ca folosesc holeshot'ul si in timpul cursei?Ca aprilia il are pe automatic ca sa zic asa?sau ceva in genul?

[damager]

Acum 30 minute, Method a spus:

Dar nu ziceau ca folosesc holeshot'ul si in timpul cursei?Ca aprilia il are pe automatic ca sa zic asa?sau ceva in genul?

Un fel de semi-automat.din cate am inteles eu, ae armeaza inainte de franare ai el intra efectiv si blocheaza pe acceleare sau franare. Nu am inteles exact cand, dar dc analizam fizic procesul, cred ca pe accelerare. 
din declarati lui Esp, el zicea ca sunt prea multe lucruri la care tre sa fie atent pilotul in viraj ca sa mai activeze alain viraj. De aia se armeaza cumva inainte. Armarea se face manual.

[PzKpfW]

6 hours ago, Method said:

Dar nu ziceau ca folosesc holeshot'ul si in timpul cursei?Ca aprilia il are pe automatic ca sa zic asa?sau ceva in genul?

 

Nu am date concrete dar nu cred, sau cel puțin ar fi foarte greu având în vedere modul de funcționare.

 

 

E un sistem foarte simplu, acționat manual prin cablu. Furca față trebuie comprimată până într-un anumit punct și acționată maneta pentru blocarea sistemului. Teoretic deci, se poate pe liniile drepte precedate de un punct de frânare important și lung și urmate de un alt punct de frânare important care să permită dezactivarea sistemelor.

 

Din ceea ce spune Aleix Espargaró se subînțelege că în timpul cursei folosesc doar squat, nu și holeshot:

 

 

On 14.10.2021 at 11:18, PzKpfW said:

holeshot (maneta mică), squat (pentru suspensia spate, clapa de lângă manșon).

 

Se pare că le-am încercat aici: holeshot-ul este clapa inferioară de lângă manșon și squat-ul se activează cu maneta mică.