Crossplane Yamaha bukan mesin bagus, keunggulan sudah hilang, kelemahan masih eksis


Membaca artikel berikut penulis jadi tertarik untuk membahas lagi teknologi crossplane motor Yamaha:
Mesin Inline 4 plus Crossplane Crankshaft itu bagai Serigala berbulu Domba

Kali ini soal efek dari penggunaan crossplane. Apa sih keunggulan utama dari crossplane?

Bukan tenaga, tapi dari power delivery. Bukan lebih nyentak, tapi sentakan ini yang justru dikurangi. Ini dijelaskan sendiri oleh yang mendesain, Masao Furusawa:
Masao Furusawa reflects on MotoGP career

I came up with a pretty good idea – the crossplane crankshaft and then right after I joined MotoGP I started a design. the test rider said was ‘this bike feels slow’. So everyone looked at me, thinking ‘Hmmm. You are the guy who thought of this…’ And then he said ‘But the lap time is so fast. It just feels slow because it is very, very smooth and stable.’

Valentino Rossi said ‘this bike is the best one’. Even though it was slow, because the power was not so much. I had prepared lots of combinations for him to try: Four-valve system, five-valve system, crossplane, single plane. And he pointed to the crossplane crankshaft bike with four-valve. So the four-valve system and crossplane crankshaft was the best, but it was also a brand new engine design, which is why the power was so slow. But despite that, Valentino still pointed to that engine and said ‘this is it’.

Ada dua poin utama sifat dari mesin crossplane, yaitu slow tapi smooth.

Perkenalan Yamaha untuk crossplane:

Penjelasan mengapa ini terjadi pernah dijelaskan di website resmi Yamaha
2009 YZF-R1

Introducing the 2009 YZF-R1, the first ever production motorcycle with a crossplane crankshaft. Crossplane technology, first pioneered in MotoGP racing with the M1, puts each connecting rod 90° from the next, with an uneven firing interval of 270°- 180°- 90°- 180°. This all but eliminates undesirable inertial crankshaft torque, which allows the engine’s compression torque to build smoothly and provide a very linear power delivery out of the corners. It’s a feeling that’s simply unmatched, like having two engines in one: the low-rpm torquey feel of a twin with the raw, high-rpm power of an inline 4.

Unlike typical in-line-four engine design, where the two outer and two inner pistons move together in pairs with 180°intervals, the crossplane crankshaft has each connecting rod 90° from the next with a unique firing order of 270° –180° – 90° – 180°. This overcomes the inherent fluctuations in inertial torque during each engine revolution, and the accompanying peaky torque characteristics. Instead, compression torque continues to build, giving the rider more linear throttle response with awesome power and traction out of the corners.

2009 Yamaha YZF-R1 Features Uneven Firing Order For Improved Power Delivery

It’s all about power – delivery of power, to be exact. That’s because the all-new R1 is the world’s first production motorcycle with a crossplane crankshaft. Originally pioneered in MotoGP racing with the M1, crossplane technology puts each crank pin 90 degrees from the next, with an uneven firing interval of 270-180-90-180 degrees. The result is incredibly smooth, roll-on power delivery with outrageous amounts of torque for a rush like you’ve never experienced before.

The unique shape of the crossplane crank smoothes out fluctuations in inertial crankshaft torque to provide very linear power delivery as the engine’s combustion torque builds, giving the rider more linear throttle response with awesome power and traction exiting corners

Dijelaskan bahwa mesin crossplane menghilangkan torsi inersia yang tidak diinginkan. Membuat torsi timbul secara halus dan jadi linier pada saat keluar tikungan. Disebut seperti gabungan tarikan mesin twin di rpm rendah dan tarikan mesin inline 4 di rpm tinggi.

Disebut bahwa crossplane akan menghilangkan torsi yang peaky. Tonjokan torsi jadi berkurang karena dibuat merata.

Kalau testimoni berkendara diceritakan sebagai berikut:
Comparison between 2005 Yamaha R1 and 2009 crossplane R1

It’s a unique experience on the road – not the amount of power but the feel of the engine. Sports bikes have red lines up to 14K revs, and most cars red-line around 4-5K, but they all have the same characteristic – the higher the revs, the harder the engine seems to be working, the more stressed it feels and the more it’s asking you the change up a gear, as I was reminded this week revving the nuts off a CBR600RR at the Ron Haslam Race School.

The cross-plane engine in the 09 R1 is so different. For me it has two personalities. Cruising under 6K revs, it feels a bit lumpy and perhaps a little unhappy, almost like a normal four-cylinder engine which is in too high a gear for the speed, and wants you to change down. Acceleration from low revs gives a very satisfying purposeful throbbing, with torque strong enough to pull a small planet out of orbit. Then when the revs rise to 7K and above, the engine smooths out like magic without the frantic feeling of a regular four. The result is that I’m always riding at 7K revs in lower gears than normal, and the engine loves it.

I never before experienced an engine which felt more relaxed at higher revs than lower revs. At motorway speeds on the 05 R1, I’d occasionally try to change up from 6th to an imaginary 7th gear. On the new bike I look down at the gear indicator to find I’m riding in 4th at 70mph to keep the revs above 7K. If I ride in 6th the revs want to rise to that relaxing 7K ride and I end up at 100+. Strange but true – at 80mph it feels almost as natural in 1st as 6th. However first gear is high and even a sustained 30mph can be hard work. I often try to change down from first when approaching tight corners and roundabouts.

Disebut yang bikin takjub bukan tenaganya tapi rasa mesinnya. Motor biasanya dibuat rpm tinggi makin terasa kerja makin keras tapi kali R1 dengan crossplane beda. Di bawah 6 ribu rpm motor terasa nggak enak, seperti pakai gigi terlalu tinggi di mesin 4 silinder. Tapi akselerasi dari rpm rendah terasa mantap torsinya. Di atas 7 ribu rpm mesin jadi halus nggak seperti mesin 4 silinder lain. Jadinya ia sering pakai rpm tinggi di gigi rendah karena nggak berasa.

Mesin disebut lebih relaks dipergunakan di rpm tinggi daripada di rpm rendah. Kalau di R1 2005 (belum crossplane) jalan pakai gigi 6 jadi pingin punya gigi 7, di R1 2009 (dengan crossplane) jadinya lebih sering pakai rpm tinggi di gigi rendah.

Dijelaskan ini terjadi karena di crossplane nggak ada piston yang berhenti bersamaan, jadinya energi yang dihasilkan jadi rata dan perputaran jadi halus dan stabil:
The Cross-plane Crank By Kevin Ash

On Yamaha’s cross-plane crankshaft, these fluctuations are all but eliminated. At no point do all the pistons stop together, as they do on a flat-plane crank. Instead the energy flow is evened out and the rotation of the crank is almost completely smooth and steady.

Even though Yamaha makes no claims of improved traction because of the uneven firing intervals of the 2009 R1 – the so-called Big Bang effect – there are still many who cite this as the motive behind the cross-plane crankshaft design. It’s not, it’s to eliminate the high frequency torque fluctuations, so the uneven firing intervals are only a side-effect, not the objective.

Dijelaskan juga bahwa tujuan dari crossplane adalah untuk menghilangkan fluktuasi / nggak stabilnya keluarnya torsi. Jadi bukan untuk mendapatkan efek big bang.

 

Dan sekarang apa yang terjadi? power delivery yang dulu dikenal smooth itu sudah hilang. Lihat saja keluhan Vinales, malah disebut brutal:
Yamaha power delivery still too “brutal” – Vinales

In the end, we have nothing that could make the bike sweeter. We have so much power but it’s delivered in a brutal way. The rear tyre slides a lot.

atau Rossi, sampai sekarang bilang Yamaha harus diperbaiki power deliverynya:

2019 Sepang MotoGP test suggests Yamaha no longer ‘lost’ – Rossi

Rossi admitted his deficit to the leading bikes was “quite big” at Sepang, and stressed the need for Yamaha to keep working on its engine’s power delivery.

Valentino Rossi Akui Motor ‘Monster’ Yamaha Berbeda dari Musim Lalu dan Dia Optimis di MotoGP 2019,

Setelah tes pra-musim MotoGP 2019 di Sepang, dia menyadari bahwa masih ada sedikit masalah dengan engine’s power delivery.

MotoGP: Have Yamaha fixed their woes?

We still need to improve though – the power delivery on the bike can be improved more with the electronics.

Jadi sekarang ini justru power delivery yang smooth yang seharusnya jadi keunggulan mesin crossplane itu sudah nggak ada. Malah justru power delivery yang jadi masalah. Sampai sekarang sistem elektronik masih gagal untuk benar benar memperbaiki masalah power delivery dari mesin crossplane yang awalnya diklaim mempunyai power delivery bagus. Padahal power delivery selama ini adalah keunggulan dari mesin crossplane. Dan kelemahan dari mesin crossplane, very slow, masih tetap terjadi. Di jalan lurus jelas dibantai motor lain seperti Ducati, Honda atau Suzuki.

Kelemahan tetap ada, keunggulan sudah hilang, dan malah jadi kelemahan utama juga. Slow tapi tetap brutal.

Menurut penulis mesin crossplane Yamaha di MotoGP sudah tidak perlu dipuji lagi.

Iklan

15 respons untuk ‘Crossplane Yamaha bukan mesin bagus, keunggulan sudah hilang, kelemahan masih eksis

  1. Suzuki GSX-RR sepertinya juga sama2 pake crossplane Om, tone suara knalpotnya yg mirip sekali dengan M1 bisa jadi buktinya. tapi kenapa Suzuki bisa mendapatkan performa mesin lebih baik dibanding M1? (top speed sedikit lebih tinggi)

    oh iya sorry OOT om, apakah penggunaan migor sbg aditif bisa juga untuk mesin diesel cc besar macam diesel buat big bus atau medium/heavy duty truck?

    atau cuma sebatas buat mesin motor doang?

    Suka

  2. crossplane bagus kalo ketemu sirkuit yg punya tikungan berkarakter flowing, tetapi masalahnya, pengguna mesin V4 terutama honda dan ducati juga sudah menemukan settingan tepat yg membuat mesin mereka bisa bejaban di sirkuit macam itu, plus keunggulan sektor akselerasi dan extra power distraight yg mustahil untuk dicapai pengguna mesin crossplane utamanya capaian power top end. FYI kata Rossi dulu pas di akhir 2003/awal 2004 waktu pertama coba M1 crossplane dia bilang ini sebenernya adalah mesin yang lemot tenaganya, tapi… capaian laptimenya lebih cepet dibanding M1 screamer 5 valve. tapi itu kan dulu jaman elektronik belom secanggih sekarang.

    Suka

    • iya lap time bisa cepat karena motor lebih bisa lebih cepat selain di lintasan lurus. Kalau menurut saya, dipaksa pakai sistem elektronik bobrok oleh Dorna justru yang jadi penyebab mesin crossplane nggak berguna.

      Suka

Bagaimana menurut bro?

Isikan data di bawah atau klik salah satu ikon untuk log in:

Logo WordPress.com

You are commenting using your WordPress.com account. Logout /  Ubah )

Foto Google

You are commenting using your Google account. Logout /  Ubah )

Gambar Twitter

You are commenting using your Twitter account. Logout /  Ubah )

Foto Facebook

You are commenting using your Facebook account. Logout /  Ubah )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.