Last week we looked at the chassis and electronics of the 2017 Suzuki GSX-R1000 and GSX-R1000R, this week we will take a closer look at the new bike’s engine via a gallery of images from Suzuki. The engine is significantly updated from the previous GSX-R’s powerplant, with different bore and stroke measurements, the addition of finger followers in the valve train, and Suzuki’s innovate variable valve timing system. Scroll through the gallery below to see all the details and learn more about the new GSX-R1000 and GSX-R1000R.
Courtesy of Suzuki
Suzuki had four design goals with the new bike’s engine: Increase top-end power without losing low-end or mid-range, optimize engine dimensions and layout to enhance cornering performance, increase driveability with advanced electronics, and emphasize durability and reliability.
Suzuki’s press material notes that the company considered using an uneven-firing-order crankshaft, like what’s used in the company’s GSX-RR MotoGP bike, as opposed to the GSX-R’s traditional even-firing-order phasing. In MotoGP, the uneven firing order helps with cornering traction and rider feel, but the layout presents significant engineering challenges, especially for a production engine. These challenges include producing strong low-end and midrange power and torque, increased vibration that requires heavier crankcases and a counterbalance shaft, and mechanical losses that contribute to overheating.
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Making good power using an uneven firing order while keeping vibration, heat and weight under control would have made the GSX-R significantly more expensive, so Suzuki chose to keep with the traditional even-firing-order configuration. During testing, engineers found that through effective chassis design and with the addition of effective electronics, traction and rider feel were enhanced even with the even firing order.
Suzuki claims an output of 199 horsepower at 13,200 rpm for the new bike, up from 182 horsepower at 11,500 rpm for the previous model. Bore and stroke measurements are more oversquare at 76.0 x 55.1mm vs. 74.5 x 57.3mm, and maximum revs have been increased from 13,500 rpm to 14,500 rpm. The new engine is 22.2mm shorter front-to-back than the old unit, and 6.6mm narrower.
Courtesy of Suzuki
Fundamental to meeting the design target of increasing top-end power without sacrificing bottom-end or midrange, Suzuki implemented the “Broad Power System,” which incorporates four technologies derived from the company’s MotoGP program: the Variable Valve Timing system, finger followers in the valve train, shower-style fuel injectors in the airbox, and new exhaust pipe valves.
Courtesy of Suzuki
The variable valve timing system is all-mechanical, with this ball-and-groove system on the intake camshaft. At low rpm, the 12 steel balls are located inward on the guide plate. At high rpm, centrifugal force pushes the balls outward in the grooves, rotating the position of the cam sprocket on the camshaft and retarding intake cam timing.
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The system takes up no extra room in the engine and has a minimal weight increase. For more details on the system and the associated patents, see Inside Suzuki’s Variable Valve Timing System.
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The new engine’s valve train utilizes finger followers, which improve valve control and allow higher rpm compared to the old bike’s more conventional bucket-tappet system.
Courtesy of Suzuki
Because the small rocker arms pivot on a fixed shaft, the moving mass per valve is significantly reduced, allowing for increased valve lift as well as a higher maximum rev limit.
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Each finger follower is six grams lighter than a conventional bucket tappet (10 grams vs. 16 grams), and has a moving mass of just three grams. The followers themselves are based on those used in the GSX-RR MotoGP bike, and include a DLC coating to increase durability.
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The camshafts themselves are hollow with thinner walls than the previous units.
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Intake valve diameter has increased from 30.0mm to 31.5mm, while exhaust valve diameter has decreased from 25mm to 24mm. Intake and exhaust valves are both titanium again; the exhaust valves had been changed to stainless steel in 2012.
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Compression ratio has been increased from 12.9:1 to 13.2:1, and the pistons have cutaway sides and the wrist pins are now DLC-coated for reduced friction.
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The water jackets in the cylinder head have been redesigned for better flow and heat-transfer efficiency. Coolant volume has been reduced by 400cc to save weight without compromising efficiency, and two radiator fans are now used instead of one.
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Even the transmission gears have been redesigned to match the increase in power. The GSX-R also features a new Suzuki Clutch Assist System, with an assist function added to the slipper clutch for reduced lever effort. The primary and final drive ratios have both been increased, with the primary ratio going from 1.617 (76/47) to 1.652 (76/46) and the final drive from 2.470 (42/17) to 2.647 (17/45). A 525 chain is now used in place of the previous 530, for reduced weight.
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The new ride-by-wire throttle bodies are 19mm shorter than the previous SDTV setup, with larger (46 vs. 44mm) bore size. Each cylinder is fed by two ultra-fine-atomization 10-hole injectors, with one mounted at a steep angle inside the throttle body and a second mounted in the top of the airbox. The injectors in the throttle body work any time the engine is running, while the Top Feed Injectors work only at high rpm.
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The showerhead-style injectors deliver fuel in an optimized spray pattern for improved combustion efficiency, for better throttle response and top-end power. The new air cleaner is designed to flow more air.
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A new Suzuki Dual-Stage Intake system offers the advantages of variable-length intake funnels without the extra cost, weight and complexity. Two of the four intake funnels use a stacked, dual-stage design with a longer funnel positioned above a short funnel, and a gap between.
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The dual-stage funnels are used on cylinders 1 and 4, and conventional single-stage funnels on cylinders 2 and 3. Generally, shorter funnels are better for high-rpm performance, while longer funnels are better for low-end and midrange power; the dual-stage funnels are said to act like long funnels are low rpm and short funnels at high rpm, offering the benefits of both.
Courtesy of Suzuki
At low- and mid-rpm, most of the air flows through the longer, upper funnel and into the short funnel, increasing low-end and midrange power and torque. But at higher rpm, more air flows around the base of the long upper funnel, and directly into the shorter, lower funnel to increase top-end power. Using the combination of two dual-stage intakes and two conventional intakes produces a broad, smooth powerband with a seamless transition through the rev range.
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The 4-into-2-into-1 exhaust retains the previous bike’s butterfly valve in the mid-pipe, but has two additional valves in the headers. A balance pipe connects cylinders 1 and 4, and a second balance pipe connects cylinders 2 and 3. Typically these balance pipes increase high-rpm power at the expense of low-end and midrange, so an additional butterfly valve has been added in each tube; these valves close at low- and mid-rpm, then open at higher rpm to reduce back pressure and increase volume for more top-end power.
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The 32-bit processor in the ECU uses multiple sensors (wheel speeds, crankshaft position, gear position, throttle position, throttle grip position and an IMU) and controls the ride-by-wire and ignition timing as part of the new riding aids package, which includes power modes, traction control, a quickshifter, launch control, and the Suzuki Easy Start System. For more details on the electronics, check out Inside the 2017 Suzuki GSX-R1000 Part 1: Chassis and Electronics.
