Cycle News - Archive Issues - 2000's

@O@@U[J@fJDD@ CiJfJD@ @fJDI!7D[J@fJD[JfJJ@fJDUCiJO @fJD@DfJD@@[?DfJD@8 @@fJiJi)[fJG!JU@[? g)UG!JW When dealing with the SVIOOOS's electronics, Suzuki officials prefer to categorize them as separate systems from the functions that they perform. Case in point: The SV's fuel.injection system and ECU are not discussed as components of the engine itself. Fuel injection chores are processed via a 32·bit CPU·equipped engine control module (ECM). The ECM is loaded with two injection maps, one for low engine loads and one for high engine loads. Sev· eral sensors are placed in the system to relay the proper information to the ECM. They consist of a throttle position sensor, crank position sensor, gear position sensor, oxygen feedback sensor and intake air pressure sensor. The crank position sensor system on the SV is much improved from the TL in that the number of trigger poles on the crank has been increased to 22 from the TL's measly four. This, says Suzuki, increases the precision of the fuel· injection system and helps to reduce emissions. Each of the SV's twin 52mm throttle bodies actually uses two butterfly valves to ensure precise fuel atomization at a given rpm. The primary valve is opened and closed by the throttle, while a sec· ondary valve located above the primary valve is opened and closed via a DC electric motor, which is actuated by the data received by the various sensors. Suzuki claims that this two-valve system, known as the Suzuki Dual Throttle Valve (SDTV), helps the SV with a generous high·speed cruise ratio in top gear. And we got the perfect chance to test the SV's high· speed cruise capability in grand fashion on the Spanish motorways that led inland from the coast toward the mountains. Spain is the true antidote for the double-nickel doldrums of the U.S.A. Imagine a whole country that thinks like the State of Montana used to about trusting the judgment of the motorist when it comes to determining what is the proper terminal velocity for a given freeway. While aboard the SV in Spain, our entourage saw speeds in excess of 130 mph. For an hour. Sometimes more. I know this because I saw 220 kilometers registering on the easy-to· read LCD instrument panel many times during the course of our adventure. The SV seems to be up to this type of task well enough to motor achieve linear throttle response in low· and mid·range rpm. When the engine is cold, an Auto Fast Idle System (AFIS) is operated by the ECM, based on information from a water temperature sen· sor plumbed into the cooling system. The AFIS then directs the sec· ondary valve to the proper posItion until the engine is sufficiently warmed up for normal operation. Suzuki has also equipped the SV with what it calls a pulsed sec· ondary air·injection system (PAIR), which injects fresh air from the airbox into the exhaust ports to ignite unbumed hydrocarbons and carbon monoxide in the spent exhaust charge. The system is com· posed of the aforementioned ECM sensors plus an additional atmospheric pressure sensor. At any given rpm, the ECM sends signals to the PAIR reed valves, which then do their thing to reduce emissions. Uke many other ECMs the SV also has a groovy diagnostics sys· tem in its repertoire. The system has two modes: an owner's mode that warns the user of impending problems by blinking the fuel injection indicator on the instrument pane's LCD screen, and a deal· er's mode which is accessed via a service·specific connector at the dealership, whereby the technician can then read information sent to the LCD. (Right) Our trip through the Spanish countryside included a long jaunt between the coastal city of Marabella and the inland town of Granada. For the most part, the SV was comfortable enough for the extended legs of our ride. (Below) Hangin' with the SV in front of the historic bullring at Ronda. The SV1000S has character, and that's no bull! suggest that it would have no trouble hanging with one of those eccentric types on his or her flashy red Duck or propeller·badged Munich special during a cross country jaunt at speeds not in keeping with the motor vehicle code. That extends to the SV's ergonomics as well. Although the pegs felt a little high to some testers on our ride, the seat·tank-pegs relationship is not at all punishing. The seat/tank junction is quite slender, allowing the rider's legs to really stay tucked into the sides of the SV. The seat itself did seem to become a bother after about 150 miles of constant riding, though. Elsewhere, the SV's sharp· looking BfJD@DfJD@8 DUDfB !J!J@U Y!@G!J[? [ffJ[J@U!JD@[?DfB !l[1 Sure, sure, the SVIOOOS sports a TL·styled 90-degree V-twin, but if you think that's because Suzuki simply plopped the TL·S or TL·R engine into a new set of rails, well, you're about 300 parts off the mark. That's how many components were changed on the SV. Suzuki engineers were emphatic that, while the engine is based on the TL, it is a com· pletely different animal. Starting with the cylinder heads, Suzuki cinched up the intake valve diameter on the SV, which now carries 36mm intake valves instead of the 40mm valves found on the TL. The SV also uses single valve springs, while the TL uses double springs. The SV features the same 14·degree valve angle that the TL has, but the SV's intake ports have been reshaped to improve low·end torque while retaining the TL's high·rpm power. The intake tract itself isn't quite as straight as the TL's, and the SV's camshaft profiles have corre· spondingly been reground slightly to optimize the higher port velocity at low rpm. The cam now pops the intake valves open and closed two crank degrees sooner than the TL. The SV is also a more compact motor thanks, in part, to Suzuki's new camshaft drive, in which the cam chain is actually run off an intermediate gear that meshes with the crankshaft rather than directly off the crank itself. Upstairs, the chain spins an idler gear that in tum meshes with the cam gears instead of spinning the cam gears directly. This arrangement means that the cam gears can be much smaller since they do not need to be of the requisite size required to rotate them at half the speed of the crank, and it also means that the components can be pulled closer together to make for a cozier layout. The cam chain itself has also been reduced from a four·row to a three· row chain for weight reduction. Spring·loaded scissor·style gears are used for the camshaft gears to reduce mechanical noise. The SVIOOOS cylinders mark the premier usage of Suzuki's new Suzuki Composite Electrochemical Material (SCEM) cylinder plating, which is made with a newly developed high-speed plating technology known as Suzuki Advanced Plating (SAP). Basically, SAP involves the infusion of SCEM over the surface of the aluminum sleeve (piston bore) at a high rate of speed to create a more uniform surface coating that boasts improved wear resistance and heat resistance and decreased weight as key benefits. As for the rotating group, the SV sports forged aluminum pistons rather than the cast units found in the TL. The forged slugs are stronger, and yet they are also IS grams lighter. They utilize the same basic shape as the GSX-R1000 and boast increased skirt rigidity. Furthermore, the SV uses an L·shaped top compression ring for better sealing and reduced weight. Connecting rods with a narrower beam than the TL's are used, which reduces weight by 30 grams per rod. The transmission is a dose-ratio six·speed unit designed to enhance the SV's sporty nature. One interesting note about the countershaft is that it is not in line with the drive· shaft and crankshaft as is the norm in four·cylinder bike engines. The three set on differ· ent planes within the crankcase, making for a more compact bottom end. The SV's power is transmitted to the tranny via a hydraulic clutch with a back torque limiter installed between the clutch hub and the countershaft to prevent the sudden transmission of power between the wheel and crankshaft. The SV clutch still uses the same number of drive and driven plates as the TL clutch (10 and 9 respectively), but the plate diameter has been increased from 138mm to 149mm. The SV's exhaust system is welded together using many irregular sections to achieve the optimal length and cross·section required to optimize low-end and midrange torque. The muffler is an aluminum oval·section unit. Rounding out the SV's engine improvements are: • A revised breather system, which is located inside the clutch for simplicity; there is no catch tank required. · Rerouted cooling passages in the cylinder head to reduce pressure losses and impeller mechanical losses. · A lightweight drive chain that uses thinner link plates for a 187·gram weight reduction. - - -- cue I e n • _ s MARCH 5, 2003 19

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