posted October 23, 2009 01:30 AM
Edited By: fish_antlers on 24 Oct 2009 00:33
More Details on Honda's VFR1200F Released
Two weeks after the initial announcement of the all-new VFR1200F, Honda releases more information about the bike's development, along with a history lesson on Honda's V4 engine. Four new videos and dozens of pictures help illustrate Honda's pride in the new model.
2010 Honda VFR1200F Development
Honda’s longstanding legacy of trend-setting machines contains one bright shining star after another, enough to populate the entire sky. Among this host of stellar bodies, however, shines one of the best and brightest machines ever to spring from the Honda clan: the VFR series of motorcycles. Immediately upon its debut in 1983, the VF750F Interceptor wielded more than enough bright-think technology to rewrite the rules in the sport bike class, and its leading-edge performance made it an immediate hit with riders and the motorcycling press.
This modern liquid-cooled V-4 engine and rectangular-section frame and race-bred chassis--startling innovations back in the day--literally advanced the state of the art in both horsepower and handling. Over the ensuing decades, these forward steps and more to follow gave the VFR spectacular credentials that led to accomplishments beyond count, including AMA and World Superbike championships, as well as best-in-class awards and top-10 honors gathered up year after year from all directions within the enthusiast press. It’s no wonder that the VFR in its many iterations developed a firm standing as one of the most-beloved motorcycles ever to set a tire to pavement.
During the course of a lifespan that stretches more than a quarter-century, the VFR ushered new technology to the marketplace as it was developed. In fact, during the 1990s, VFR development sprinted so far forward Honda split its V-4 line in two as the racing-oriented RC30 and RC45 advanced in concept and execution to win ever-greater glory on tracks the world over, while the VFR/Interceptor evolved into the preeminent street-going sport bike for those who enjoy the challenge of the road and the thrill of giving their bike a thorough workout, whether over short distances or the long haul.
Now this heritage of innovation within Honda’s V-4 lineup enters the next generation of new technology and uncompromising rider benefits--with the 2010 VFR1200F. Here in the VFR1200F, we fully recognize Honda’s V-4 heritage and VFR tradition, but it has been re-created in astonishingly original form through the fusion of advanced concepts imported from the MotoGP world and other cutting-edge environments. Net result: a sport motorcycle created for the sheer joy of riding, a machine custom tailored for experienced hands who ride hard, ride long, ride far and ride often.
- Honda MotoGP engine technology and architecture
- Light and compact 1237cc liquid-cooled 76-degree V-4
- Unique cylinder layout with rear two cylinders located innermost on the crankshaft; front cylinders located outboard
- Symmetrically Coupled Phase-shift Crankshaft uses 28-degree crankpin offset to eliminate primary engine vibration
- Asymmetrical exhaust lengths between front and rear cylinders
- Throttle By Wire
- Lightweight and compact Unicam® valvetrain
- Continuous oil pressure monitoring
- Optional dual-clutch automatic transmission featuring manual mode and automatic mode with D and S modes and paddle-style shifters
- Honda slipper clutch in manual-shift model
- GP technology layer-concept aero fairing
- Honda Pro Arm® single-sided swingarm with single shock
- Next-generation shaft drive system with offset pivot point and sliding constant-velocity joint
- New controls with smoother and more precise tactile feel
- New-technology seat construction
At the heart of the VFR1200F rests a light and compact 1237cc liquid-cooled 76-degree V-4 engine that draws directly from Honda’s V-4 RC212V MotoGP technology. Mass centralization plays a key role throughout this design, and as a result the VFR1200F incorporates a unique cylinder layout placing the rear two cylinders inboard in the center of the crankshaft, while the front cylinders are located outboard. Such a configuration narrows the rear cylinder head substantially as well as the entire rear section of the engine, right at the key rider/motorcycle interface--the seating area. Because the engine boasts remarkably slim dimensions, especially at the rear cylinders--overall, it’s more compact than the engine from the 781cc Interceptor--the entire chassis and seating area of this 1237cc machine features a distinctly narrowed profile. These pronounced, wasp-waisted ergonomics allow the rider to sit down in the bike rather than feeling perched atop the machine, and as another benefit the rider has a shorter reach down to the ground when bringing the bike to a stop.
The VFR1200F engine also incorporates a special high-strength Symmetrically Coupled Phase-shift Crankshaft that features a 28-degree crankpin offset that works in concert with the 76-degree Vee angle to essentially negate primary engine vibration for smooth running. And because the powerplant now has perfect primary balance, the need for a balance shaft is eliminated, which allows for a more compact engine and also yields a weight savings of nearly 3 pounds. To accentuate the V-4 feel of the VFR1200F, a unique ignition sequence of 104 degrees–256 degrees–104 degrees–256 degrees between cylinder firings highlights the distinctive VFR beat. Another design element that adds to the VFR1200F’s distinctive feel can be found in the exhaust system: note that the head pipes for the two front cylinders carry a substantially longer length than the headers for the rear cylinders, a Honda first. This asymmetrical pipe length alters the tuning of the exhaust pulses to create a unique power delivery, an intriguing blend of V-4 torque and aggressive in-line rush. And make no mistake: the VFR1200F delivers Honda’s famous V-4 power in spades, as more than 90 percent of peak engine torque kicks in at a mere 4000 rpm, giving this machine incredible roll-on acceleration in every gear.
A great deal of credit for the VFR1200F’s compact engine size and prodigious power output must go to the Unicam valvetrain, a Honda-exclusive system that first debuted on the championship-winning CRF450R motocross machine. A single overhead camshaft directly actuates two intake valves per cylinder while integrating roller rocker arms with screw-type adjusters to actuate two exhaust valves per cylinder. This Unicam technology saves weight and space over a comparable dual-overhead-camshaft design while still maintaining a five-digit redline of 10,200 rpm. As another benefit, this Unicam setup allows for a very flat combustion chamber for a quicker, more efficient burn.
Another concept carried over from MotoGP design and first offered to the public with Honda’s CRF® motocross line is the application of a sealed crankcase system that maintains a mild negative pressure to minimize mechanical pumping or “windage” losses. This system also provides the advantages of a dry sump design (decreased oil churning losses) without the separate oil tank. A scavenging pump pulls oil and gasses out of the crank chamber, and this reduction in atmospheric pressure reduces resistance as the reciprocating engine elements--crankshaft, pistons and connecting rods--move. Net result: extra power, enhanced throttle response and improved fuel efficiency. The VFR1200F also incorporates a new, more sophisticated constant oil-pressure monitoring system that has the ability to read a range of variations in oil pressure within a safe operating zone, not just report the presence of minimal oil pressure or no pressure.
The new VFR1200F sports another first for Honda among its numerous technical credentials; the use of a Throttle By Wire (TBW) system. With the throttle valve layout in the Programmed Fuel Injection (PGM-FI) system now freed from the restrictions imposed by a mechanically linked/actuated throttle-grip system, the VFR1200F’s TBW setup can be made more compact and lighter than conventional cable-operated systems. In addition, this setup incorporates an Electronic Control Unit (ECU) to process information from rider throttle control input, engine speed via a crankshaft position sensor, manifold absolute pressure, gear position, vehicle speed, engine coolant and intake air temperatures, and throttle position help the TBW system to return an even more accurate throttle response in a manner that is more sensitive to rider inputs--large or small--compared to a mechanically linked system, yet with fuel delivery that is smoother and more precise than would be otherwise possible.
The end benefit for the rider is an unprecedented level of control and feel through the throttle, a true next-generation, more direct level of connectivity with the machine that heightens the riding experience. In addition, the VFR1200F’s TBW system eliminates the need for the Idle Air Control Valve used in other Honda PGM-FI systems to deliver a consistent idle; TBW simply delivers more sensitive and accurate fuel metering response to rider input compared to mechanically linked PGM-F1 systems regardless of riding conditions. From where the rider sits, TBW works virtually invisibly to improve engine responsiveness and operation, provide a more linear and well-connected throttle feeling, and also improve fuel efficiency.
As befitting of a super-sophisticated sport machine, the VFR1200F can be had with a standard six-speed manual gearbox or with the option of an impressively new piece of technology for motorcycles, Honda’s Dual Clutch Transmission, the world’s first fully automatic motorcycle dual clutch transmission for large-displacement sport bikes. This new transmission offers riders the enjoyment of full sport riding capabilities along with easy and seamless operation, while also delivering fuel efficiency equal to or better than a conventional manual transmission. To respond to rider demands throughout a broad range of conditions and situations, the transmission offers three operating modes: two full-auto modes (D-mode for regular operation and S-mode for sporty riding), and a six-speed gear-select mode for full rider control via a paddle-shifter-type setup that delivers the same shifting response as a manual transmission. For more details, see the attached technical description of this innovative Honda Dual Clutch Transmission.
In keeping with its serious sporting abilities, the conventional manual-shift VFR1200F comes equipped with a slipper clutch mechanism. This system acts like other Honda slipper clutch systems to moderate the effect of deceleration torque (or “back torque”) on the rear wheel during aggressive corner entries with heavy engine braking, thereby allowing engine braking to slow the bike without causing the rear tire to chatter. It’s an elegantly simple way to lend the assistance of a slipper clutch to sport riders with a minimum of weight and complexity.
Along with the VFR1200F’s substantial sporting prowess come additional high-tech features that create a riding experience laden with many sophisticated touches. Case in point: the VFR1200F incorporates four dampers within the engine and drivetrain to smooth power delivery: a clutch damper, final damper, cam damper and tornado damper all work in concert to create smooth power delivery without losing that connected feel between throttle and contact patch.
The VFR1200F rolling chassis centers on a four-piece aluminum twin-spar diamond configuration frame that is both lightweight and rigid. The swingarm and driveshaft lengths are optimized without extending the overall length of the motorcycle through the use of another clever and sophisticated touch: the output shaft is placed below the transmission countershaft to create a more compact engine and allow for a longer swingarm without extending the total wheelbase--a move that enhances both handling and traction without resorting to dimensions beyond the moderate 60.8-inch wheelbase.
Honda’s distinctive single-sided Pro-Arm swingarm is placed within a wide-span frame swingarm pivot area for increased chassis rigidity, and the swingarm pivot sits in an offset position above the driveshaft. This highly developed shaft drive system features a drive shaft that passes below the swingarm pivot. This allows a wider swingarm pivot/frame mounting structure resulting in greater strength and rigidity. A sliding constant velocity (CV) joint compensates for drive shaft length variations throughout the rear wheel’s arc of travel. Thanks to this new configuration and the rigidity of the pivot structure, the new shaft drive system enhances cornering ability, high-speed handling and traction capability compared to prior-generation shaft drives.
The VFR1200F’s single-sided Pro-Arm® swingarm system incorporates a single Pro-Link® gas-charged shock that includes a handy, easy-to-alter remote spring preload adjuster, and the shock is also adjustable for rebound damping. The shock delivers 5.1 inches of wheel travel, while up front the 43mm inverted cartridge fork delivers 4.7 inches of travel and also offers spring preload adjustability. All together, this combination of adjustability in the suspension at both ends give the VFR1200F a broad range of application, be it hard sport riding, more casual long-distance trips or two-up adventuring.
The VFR1200F also features sophisticated brake technology that complements its sporting abilities. Powerful new six-piston front calipers act on large 320mm floating discs and the two-piston rear caliper works against a 276mm disc. Honda’s Combined Braking System (CBS) creates the optimal balance of front and rear braking forces. With this particular CBS setup, actuation of the front brake lever activates all pistons in the right-side caliper, and four pistons on the left side; the other two pistons are actuated when the rear brake is applied. However, to maintain equal braking force when the front brake is applied, those right-side pistons measure 25mm in diameter while in the left caliper the pistons measure 27mm and 30mm in diameter. In this case, asymmetrical brake pistons equal balanced braking loads--another bit of forward thinking that makes the VFR1200F so advanced. Also, the addition of a compact and lightweight ABS supports both the motorcycle’s exceptional sports riding potential and its long-distance proficiency.
A balance of positive and negative bodywork surfaces gives the VFR1200F a light, open look while also creating a profile that slices through the wind with the least possible resistance. In addition to this modern, cutting-edge look comes a number of distinct benefits. Closer inspection reveals that Honda’s designers and engineers worked together to utilize this uniquely attractive shape to also generate optimal airflow and maximize heat management. The fairing design incorporates two layers that harness flowing air to gain several dynamic advantages. Air entering between the layers and through two oval-shaped spaces in the front of the fairing is channeled to enhance the bike’s handling at higher speeds and cool the engine, and air is also deflected around the rider’s legs for a cooler, more comfortable ride.
Engine cooling is optimized by effectively increasing the speed of the airflow before it reaches the radiators by channeling it through tapered apertures. An additional vent in the side of the bodywork directs air downwards for engine cooling. And the hot, exhausted air is channeled away from the rider for greater comfort. Further ducting and heat shielding technology channel heat away from the rider’s environment, thus improving comfort for both the rider and passenger.
For decades, Honda products have stood out among the crowd thanks to a distinctively high level of fit and finish, but the 2010 VFR1200F raises the stakes even higher than ever before in the arena of quality control. A high attention to detail and quality is evident everywhere, but take special notice of where the front cowl and body are fused together, creating one smooth, unified, aerodynamic surface. This incredibly tight and precise fit comes courtesy of a new generation of rectangular-shaped fasteners that locate body panels within two dimensions for a fit that is tighter than would otherwise be possible with conventional fasteners. And of course the very latest production technologies used at the new Kumamoto Plant in Japan where the VFR1200F is built contribute to the bike’s exceptional fit and finish. It’s classic Honda attention to detail, but at its newest and finest.
Note also that new Honda technology is at work in the seat. Here you’ll see shaping and forming details like never before, thanks to a new process that literally bonds the seat cover (which has a special, tactile surface) to the seat foam. Net result: exquisite control to shape every part of the seat for improved ergonomics as well as the ability to execute intricate patterns.
More attention to detail has been showered upon key components of the VFR1200F that interact with the rider’s fingertips through new premium control elements. Here Honda’s engineers have developed next-generation switches and controls for the VFR1200F that return a smoother and more precise feel when actuated; the tactile response feels more direct than ever before.
From the finest details to the grandest application of racetrack technology, the 2010 VFR1200F comes laden with innovation upon innovation, a machine that once again changes the state of the motorcycling art. In each case, however, the target of these benefits remains the same: The rider. The VFR1200F brings to motorcycling enthusiasts a unique blend of elegant sophistication and hard-core sport performance never before offered to the riding public. Such a unique and lofty mission serves as the perfect target for the 2010 V-4 VFR1200F, a machine that traces its deep and rich V-4 heritage to a true revolution in sport bike design, and one that is bound to repeat the sport-altering history of its famed forebears.
Honda VFR1200F Dual Clutch Transmission
For decades, manual shifting has served as an integral and required part of the motorcycling experience. But just as automatic shifting technologies were utilized to improve lap times at the highest levels of automobile racing, automatic shifting has at last made its way into a large displacement, high-performance motorcycle. With the rollout of the 2010 VFR1200F, Honda introduces the Dual Clutch Transmission, the world’s first fully automatic motorcycle dual clutch transmission for large-displacement sport bikes. This new transmission offers riders the enjoyment of full sport riding capabilities along with easy and seamless operation, applied in a powerful, large-displacement machine. At the same time, this transmission’s superior efficiency delivers fuel efficiency equal to or better than a conventional manual transmission.
This world’s-first motorcycle dual clutch transmission features a light and compact design that allows it to be combined with existing engines without substantial layout modification. Further, the new transmission delivers the precise acceleration control that is an integral part of spirited sport riding thanks to electronic control technology that helps ensure smooth, seamless gear changes. And since it uses conventional transmission gears, it’s as rugged and durable as Honda’s conventional manual transmissions as well as being equally efficient.
To respond to rider demands throughout a broad range of conditions and situations, the transmission offers three operating modes: two full-auto modes (D-mode for regular operation and S-mode for sporty riding), and a six-speed gear-select mode for full rider control via paddle-shifter-type controls that deliver the same shifting response as a manual transmission. As an indication of the deep level of innovation involved in developing such a novel transmission, Honda has 100 patents pending related to this design.
The Dual Clutch Transmission configuration employs independent clutches for the odd-numbered gears (1st, 3rd, 5th) and the even-numbered gears (2nd, 4th, 6th), respectively. The two clutches operate alternately to effect gear changes. For example, when changing from 1st to 2nd gear, the computer detects the up-shift and engages 2nd gear, then releases the 1st-gear clutch while engaging the 2nd-gear clutch to achieve a smooth gear change. It’s a fast and efficient transition that delivers extremely quick shifts.
The VFR1200F’s transmission employs dual concentric input shafts (one shaft runs inside the other hollow shaft), an exclusive in-line clutch design, and concentration of hydraulic circuitry beneath the engine cover to achieve a compact design. Compactness and lightness is further enhanced through the use of a simple shift mechanism design based on that of a conventional motorcycle shift drum. Optimized shift scheduling achieves fuel efficiency equal to or better than that of a fully manual transmission, enabling this Dual Clutch Transmission to deliver both sporty riding and economical performance.
Once an essential skill required for the riding experience, manual operation of a clutch and shift mechanism is no longer a prerequisite or an impediment for motorcycle operation. Both riders of less experience and skilled riders have one less task to deal with, which means more brain power to focus on all the other joys of sport riding. Of course, many riders may still prefer a manual-shift transmission, which is why the VFR1200F gives you a choice. But for those who have been waiting for a high-performance motorcycle featuring true automatic shift modes with easy, seamless operation, as well as riders who are eager to embrace new technology, the 2010 VFR1200F with Dual Clutch Transmission puts full-on sport-bike abilities at your fingertips--automatically.
Honda V-4 Production Bike Timeline
1982: V45 Sabre and Magna
- Honda introduces the sophistication of V-4 power to street-going motorcycles in two different forms
- The VF750S V45 Sabre® delivers lightweight Superbike performance to sport-oriented riders
- The Sabre’s 748cc DOHC V-4 engine with four valves per cylinder combines two downdraft carburetors and two sidedraft carburetors for stellar performance
- The VF750C V45 Magna® cruiser combines traditional cruiser styling with unmatched engine performance
- Compact engine dimensions help give the Magna a low seat height measuring less than 30 inches
1983: VF750F V45 Interceptor; VF1100 V65 Magna
- First-ever 750 Interceptor® rewrites the rules in the sportbike class, wins Bike of the Year awards from two magazines in the U.S.
- A radically new rectangular-section frame brings racetrack design to the street bike realm in a time when round-tube frames are the norm
- High-performance 748cc liquid-cooled V-4 engine makes the Interceptor the quickest 750 on the market
- The new V65 Magna defines the term “power cruiser” with its incredibly strong 1098cc DOHC V-4 engine
- At the time, the V65 Magna is the quickest custom-style motorcycle ever built
- In addition to its prodigious power, the V65 Magna’s overdrive sixth gear allows this stylish bike to cruise with effortless ease
1984: VF500F 500 Interceptor; VF500C V30 Magna; VF700F Interceptor; VF700S Sabre; VF700 Magna; VF1000F 1000 Interceptor; VF1100S V65 Sabre
- Honda fills out its family of V-4 street bikes by introducing seven new models spanning a wide range of styles
- Like its larger 750 sibling, the 500 Interceptor sets new standards of performance, this time in the mid-sized sportbike class
- Barely topping 400 pounds, the 500 Interceptor immediately gains a reputation for exemplary sport bike handling
- The 1000 Interceptor instantly becomes the ultimate high-performance liter-class sport machine among all streetbikes
- Introduction of the 700cc and 1100cc Sabre models accelerates the pace of evolution among sport-touring motorcycles
- The high-tech V65 Sabre churns out 121 horsepower from its 1098cc V-4-an incredible feat for the era and enough to make it a long-distance mount par excellence
- The V30 Magna delivers strong V-4 power to the mid-size custom class while offering classic styling cues
- Only a year after introducing the VF1000R Interceptor, Honda rolls out a new replacement derived from Honda’s FWS V-4 racer: the VF1000R
- The new VF1000R boasts gear-driven dual overhead cams and a higher compression ratio of 11.0:1 for more power
- Full bodywork gives the VF1000R extremely efficient aerodynamic properties, and the sophisticated rolling chassis provides state-of-the-art literbike handling
- For the 750 Interceptor’s first makeover, Honda engineers create an all-new V-4 engine with gear-driven cams and an industry-leading chassis
- The VFR’s innovative race-inspired aluminum frame helps reduce curb weight by nearly 45 pounds, thereby creating an unbelievably agile sport bike
- Now dubbed the VFR750 rather than VF, the new Interceptor features a 180-degree crankshaft and a six-speed gearbox replacing the prior five-speed design
- The European market receives a new VFR750R that is aimed at track use, which will later enter the American market as the RC30
1990: VFR750F; ST1100
- With the simultaneous introduction in the U.S. of the RC30 and the second-generation VFR750R, Honda’s 750 V-4 line splits in two for a more focused lineup
- The racier RC30, destined for Superbike and World Endurance racing, features super-sophisticated suspension components and elevated horsepower
- Titanium connecting rods, gear-driven camshafts and quick-release wheels were some of the items that earmarked the RC30 as a machine intended primarily for track use
- Second-generation VFR750F shares many features with the RC30, including a twin-spar aluminum frame and Pro-Arm single-sided swingarm
- Honda redefines sport-touring with the V4 ST1100, a long-range specialist that will become a legend in its own time
- The ST1100 features a liquid-cooled 90-degree V-4 displacing 1084cc that resides in a longitudinal layout, and the extraordinary torque output of this engine wins fans in the hard-core sport-touring market the world over
- Cycle magazine declares, “The ST’s mission is sharply and narrowly defined: comfortable high-speed, long-distance passage.”
- Honda introduces a very limited production NR750 oval-piston street bike. It is the most exotic motorcycle ever offered by a manufacturer, and becomes an instant collector’s item
- Based on NR500 race-bike design, each cylinder boasts two connecting rods and eight valves to maximize valve-to-piston area, much like a short-stroke V-8 engine
- PGM-FI fuel-injection, carbon fiber bodywork, an underseat exhaust, magnesium wheels and Pro-Arm single-sided swingarm help make the NR750 a true factory-built exotic
1994: VFR750F; RC45
- Third-generation street-going VFR750F is almost 20 pounds lighter and reveals styling cues derived from the legendary oval-piston NR750
- The racing RVF750 begets the RC45, an all-new street-legal racing platform that improves on the RC30 in every way: it’s lighter, faster, more compact and ultra-sophisticated
- The RC45’s all-new engine incorporates Programmed Fuel Injection (PGM-FI) for more power and enhanced throttle response
- The redesigned RC45 twin-spar aluminum frame increases chassis rigidity and stability, and a more sophisticated suspension system delivers sharper handling
1998: VFR750F; RC45
- Completely redesigned for 1998, the Interceptor once again redefines street-going sport bike performance by infusing new racetrack technology
- Ultra-sophisticated features, including a pivotless Pro-Arm chassis, aluminum-composite cylinder sleeves and more, bring the Interceptor to the leading edge of motorcycle technology
- A boost in displacement to 781cc makes this first VFR800 an eminently adept choice as a do-it-all mount, and this status is confirmed when Motorcyclist magazine names the new Interceptor as Motorcycle of the Year
- This new-generation sport bike introduces VTEC® valve train to the Interceptor’s V-4 engine, varying valve actuation for enhanced power characteristics
- VTEC allows the high-velocity breathing advantages of a two-valve head at low engine speeds while endowing high-flow four-valve breathing at high revs for a broad powerband
- New center-up exhaust increases cornering clearance and opens up the rear quarters for optional hard saddlebags
- An all-new V-4 powered ST1300 raises the stakes in sport-touring circles with more power and distinctly sporty handling for effortless long-range riding
- At 1261cc, the new V-4 ST engine is 16 percent larger in displacement than the previous version, good for an impressive 125 bhp
- The new all-aluminum frame and swingarm alone shave 4.3 pounds compared to their previous steel counterparts and also help deliver next-generation handling characteristics
- Next-generation tuning touches applied to the Interceptor’s VTEC system enhance the Interceptor’s broad-shouldered powerband
- A host of new styling upgrades give the Interceptor a fresh look to accompany its revamped power characteristics.
posted October 23, 2009 05:41 AM
Edited By: Shane661 on 23 Oct 2009 12:42
You have to wonder why they went with a SOHC design? I imagine that is part of the reason that the redline is so low, judging by the length of the arms that actuate the exhaust valves.
"Honda’s longstanding legacy of trend-setting machines contains one bright shining star after another, enough to populate the entire sky."
posted October 23, 2009 06:45 AM
Edited By: Shane661 on 23 Oct 2009 13:48
Yes, I would say that 10200 rpm is a low redline. I happen to own a 1985 VF1000R....11k rpm redline and that bike is almost 25 years old.
Piston speeds are relatively low for this engine. It has only a 60mm stroke.
posted October 23, 2009 11:43 AM
the unicam is race proven and allows for a more compact engine- better mass cetralization. they also claim to produce 90% of total torque at just 4000 rpm so there might not have been any benefit to having a higher rev limit. or they could be waiting for next year to release the chain driven gt busa beater version with 200 hp and a14500 rpm rev limit lol. would't that be sweet
"never drive faster than you can see, besides it's all in the reflexes"