HEART OF THE MAT­TER

Suzuki’s 16-year power play with the GSX-R1000

Motorcycle News (UK) - - This Week -

Go big or go home

When it comes to de­sign, there is­nõt any­thing par­tic­u­larly spe­cial about the orig­i­nal GSX-R1000 engine. It is es­sen­tially a larger- ca­pac­ity GSX-R750 Y mo­tor. So why did it cause such a stir? Itõs all down to ca­pac­ity, ef­fi­ciency and re­duc­ing me­chan­i­cal fric­tion losses.

With the K1ÕS DOHC in­line four, Suzuki con­cen­trated on get­ting the air and fuel into the cylin­der as fast as pos­si­ble and at the op­ti­mum ra­tio be­fore burning it at the right time and har­ness­ing as much of the power pro­duced as pos­si­ble with min­i­mal losses. This was achieved by us­ing a fast 16-bit pro­ces­sor in the bikeõs ECU that was matched to an eight-point crank sen­sor (dou­ble the num­ber of sen­sors on the GSX-R750 and twice the pro­cess­ing power) and Suzuk­iõs dual throt­tle valve system.

To en­sure me­chan­i­cal fric­tion was kept as low as pos­si­ble, the bal­ancer shaft runs in plain in­sert bear­ings rather than roller bear­ings and weight was trimmed off mov­ing items such as pistons (which are 3g lighter than the 750Õs), valves, cams, etc. The net re­sult was con­sid­er­ably more power and torque than its ri­vals, as well as a lighter over­all kerb weight, and there­fore a faster sports­bike. Sim­ple en­gi­neer­ing prin­ci­ples done well Ð how very Suzuki.

Strengths Sheer power and torque com­bined with a light over­all weight. Weak­nesses The chas­sis could­nõt al­ways deal with the power. Im­pact The K1 set a new per­for­mance tar­get for litre bikes. Any up­dates? The K3/4 engine gained a 32-bit pro­ces­sor, new in­jec­tors and new ven­ti­la­tion holes to equalise in­ter­nal engine pres­sures. Power was in­creased by 3bhp.

‘It’s all down to ca­pac­ity, ef­fi­ciency and re­duc­ing fric­tion losses’

All about the bal­ance

With the Mo­togp project de­cided as a V4, the new GSX-R1000 engine was de­vel­oped purely for the road and as such gained a 0.4mm big­ger bore to take it to 998.6cc. In­side the cylin­ders, new pistons were lighter and the com­pres­sion ra­tio was raised from 12:1 to 12.5:1 and matched to 1mm larger in­take valves that were made of ti­ta­nium for the first time, sav­ing 94.4g.

Seek­ing to gain more of the ben­e­fits from equal­is­ing the engine’s in­ter­nal pres­sure, the ven­ti­la­tion holes be­tween cylin­ders were in­creased in size by 4mm and the crank and con rods strength­ened to deal with a claimed 17bhp in­crease in power and a new 1000rpm higher, 13,500rpm red line. A new twin in­jec­tor fuel-in­jec­tion system with the sec­ondary one only op­er­at­ing at high rpm was also new.

Al­ter­ations to the gear­box, which had be­come no­to­ri­ous for its weak­ness, saw the shift fork re­designed, the ra­tios moved slightly closer to­gether and a slipper clutch fit­ted for the first time. How­ever, what re­ally made the K5 stand out was the unique ti­ta­nium trape­zoidal ex­haust.

Strengths De­spite its in­crease in power, the K5’s new chas­sis and over­all bal­ance al­lows rid­ers to har­ness this ex­tra grunt.

Weak­nesses Very few, it’s still a won­der­fully com­plete pack­age.

Im­pact The K5 demon­strated that raw power isn’t any­thing with­out con­trol.

Any up­dates? The K7/8’s han­dling was ru­ined by heavy twin ex­haust pipes and more re­laxed chas­sis ge­om­e­try, how­ever the engine gained 4bhp through larger ven­ti­la­tion holes, new in­jec­tors and it also de­buted a world first of vari­able power modes.

Re­mem­ber me?

With the un­pop­u­lar K7/8 model see­ing the GSX-R1000 knocked off its perch at the top of the su­per­bike tree, Suzuki’s prob­lems were com­pounded by the ar­rival in 2008 of the new Honda Fire­blade. But they had a plan.

The K9 was pow­ered by a new GSX-R mo­tor that while not rad­i­cally dif­fer­ent in its over­all con­cept, did have some sub­stan­tial changes within it. To in­crease the swingarm’s length for bet­ter drive, the K9’s engine was made 59mm shorter front to back than the old K5 engine, al­low­ing Suzuki to fit a 32mm longer swingarm. This short­en­ing was achieved through a new stacked gear­box (like the GSX-R600 and GSX-R750’S de­sign) and re­duc­ing the engine cast­ings from three to two.

In­side the mo­tor the bore was in­creased by 1.1mm and the stroke re­duced by 1.7mm, in keep­ing with the ‘over-square’ phi­los­o­phy of mod­ern sports­bikes, and the pistons re- pro­filed to go with an al­tered head and cams. In­side the head the GSX-R’S in­let and ex­haust valves grew 1mm to 31mm and 25mm re­spec­tively while dou­ble valve springs were also added. Fi­nally, to boost the mo­tor’s midrange, the length of the in­take trum­pets was var­ied with the two in­ner ones longer than the outer two.

When you look at the spec sheet, Suzuki went to town with the K9, how­ever their ri­vals went even fur­ther and the new cross­plane Yamaha R1 and BMW S1000RR rather took the shine off Suzuki’s lat­est GSX-R.

Strengths The engine’s midrange. Weak­nesses The S1000RR was more pow­er­ful and had elec­tronic rider aids. Im­pact The K9 failed to set the world on fire and, sadly, was largely for­got­ten about.

Any up­dates? The GSX-R1000 L2 was the last GSX-R1000 model be­fore the rad­i­cally dif­fer­ent 2017 bike. It uses the same ba­sic mo­tor as the K9, how­ever Suzuki made some sig­nif­i­cant al­ter­ations within it to boost its power and torque. The pistons are 11% lighter and the com­pres­sion ra­tio is in­creased thanks to a re­shaped pis­ton crown. A lighter valve train is op­er­ated by re-pro­filed cams with an al­tered du­ra­tion on the ex­haust port but the same as the K9 on the in­take to re­duce the valve over­lap and boost top end. Un­der the pistons, the ven­ti­la­tion holes are re­designed to re­duce pump­ing losses and the fuel maps tweaked. Suzuki only claimed a power in­crease of 1bhp, but the bike felt health­ier and also lighter han­dling thanks to a new sin­gle ex­haust and al­tered chas­sis.

‘Suzuki went to town with the K9, how­ever their ri­vals went even fur­ther ’

The K1 engine ex­posed in all its com­po­nent glory With 161bhp, the K1 moved the power game on an­other leap Noth­ing overly clever, just an op­ti­mi­sa­tion of the burn Red­line of 12,500rpm meant big midrange The K1 still looks clas­si­cally GSX-R mean

GSX-R1000 K1 to K4 2001-2004

Troy Corser broke the V-twin’s stran­gle­hold in WSB

GSX-R1000 K5 to K8 2005-2008

Pro­duc­ing 164bhp re­quires lots of air BPF forks ar­rived with the K9 model A wide back is a typ­i­cal GSX-R look The K9 was far from a dog, yet proved un­pop­u­lar

GSX-R1000 K9 to L6 2009-2016 When it comes to grunt, the L2 engine has it in spades and is vastly un­der-rated

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