Suzuki GSX-R 750WP
Suzuki GSX-R 750WP | |
Manufacturer | |
---|---|
Production | 1993 |
Class | [[:Category:Sportbike motorcycles|Sportbike]] [[Category:Sportbike motorcycles]] |
Engine | Four stroke, transverse four cylinder, DOHC, 4 valves per cylinder. |
Compression ratio | 11.8:1 |
Top Speed | 257.9 km/h / 160.3 mph |
Ignition | Computer controlled electronic ignition |
Spark Plug | NGK, CR9EK |
Transmission | 6 Speed, constant mesh |
Frame | 5-sided aluminum pipe frame with sand-casted steering head section and cast swing arm pivot |
Suspension | Front: Showa 41 mm cartridge style upside-down forks, preload, compression and rebound adjustable Rear: Full floater, preload, compression and rebound adjustable |
Brakes | Front: 2 x 310 mm Discs, 4 piston Nissin calipers Rear: Single 240 mm disc, 2 piston Nissin caliper |
Front Tire | 120/70 ZR17 |
Rear Tire | 170/60 ZR17 |
Wheelbase | 1440 mm / 56.7 in. |
Seat Height | 790 mm / 31.1 in |
Weight | 208 kg / 458.6 lbs (dry), 234 kg / 516 lbs. (wet) |
Recommended Oil | Suzuki ECSTAR 10w40 |
Fuel Capacity | 21 Liters / 5.5 US US gal / 4.6 Imp gal |
Manuals | Service Manual |
It could reach a top speed of 257.9 km/h / 160.3 mph.
Engine
The engine was a Liquid cooled cooled Four stroke, transverse four cylinder, DOHC, 4 valves per cylinder.. The engine featured a 11.8:1 compression ratio.
Drive
Power was moderated via the Cable operated, wet multiple, coil spring.
Chassis
It came with a 120/70 ZR17 front tire and a 170/60 ZR17 rear tire. Stopping was achieved via 2 x 310 mm Discs, 4 piston Nissin calipers in the front and a Single 240 mm disc, 2 piston Nissin caliper in the rear. The front suspension was a Showa 41 mm cartridge style upside-down forks, preload, compression and rebound adjustable while the rear was equipped with a Full floater, preload, compression and rebound adjustable. The GSX-R 750WP was fitted with a 21 Liters / 5.5 US US gal / 4.6 Imp gal fuel tank. The bike weighed just 208 kg / 458.6 lbs. The wheelbase was 1440 mm / 56.7 in. long.
Photos
Overview
Suzuki GSX-R 750WP
The second year or the water-cooled engine, the 1993-year's GSX-R750WP
received mostly cosmetic changes. The liquid-cooled DOHC 4 valve engine was
designed to lower the center of gravity by positioning the crankshaft low.
The valve angle was set at 16 degrees, 4 degrees less than that of the final
air-cooled SACS engine Thinner valve stems and Direct-action valve train
also contributed to make this engine a compact unit excelling at high rpm,
achieving high compression ratio of 11.8, the highest in this class. SCAI
(Suzuki Condensed Air Intake) system allowed optimal intake of fresh air to
the engine under all conditions.
ONE OF THIS YEAR'S MOST EXCITING, MOST IMPORTANT
motorcycles is not sold in the United States. Not
yet, at least.
Suzuki decided not to bring its new liquid-cooled GSX-R750 repli-racer
into the U.S. this year because its air-and-oil-cooled 750 continues to offer
class-leading performance at a reasonable price. Even though the new 750 is for
sale in Canada, Europe and Australia, Suzuki felt that introducing a more
expensive GSX-R to the soft American market would unnecessarily alienate
cost-conscious buyers.
Next year should be a different matter. The current U.S. GSX-R
engine-in its seventh year of production-is showing its age. Fine for street
use, the air-and-oil-cooled motor has trouble dissipating heat when modified,
which has led to engine failures in competition. Introduced in 1985 as a
road-racer for the street, the GSX-R750 no longer is a threat on the racetrack,
an untenable marketing position. Also, industry grapevines are alive with the
rumors that Honda, Kawasaki and perhaps Yamaha are poised to introduce updated
750s. Clearly, to stay in the hunt on the racetrack and in the showroom, Suzuki
has to bring the liquid-cooled 750 to the USA in 1993.
In anticipation, Cycle World jetted to Canada to test the
latest GSX-R750 at Shannonville Motorsports Park, located about 115 miles
northeast of Toronto, Ontario. We borrowed two GSX-Rs-a liquid-cooled 1992 model
and, for comparison purposes, an air-and-oil-cooled 1991 version, identical to
the '92 U.S. model. Cycle World, a Toronto-based Suzuki dealer, and Cycle City,
a Burlington, Ontario, Suzuki/Yamaha dealer, loaned us the bikes, while
Competition Systems of Markham, Ontario, provided track-side support.
Visually, the new GSX-R, with its stunning lines, aluminum frame
and heavily finned engine, bears a strong resemblance to previous Suzuki
sportbikes. This is intentional: Suzuki wanted visual and mechanical continuity
from one GSX-R generation to the next. Fundamentally, the 750 is identical to
the GSX-R600 recently introduced here in the U.S. The exceptions are the 750's
larger bore, longer stroke, bigger valves, larger carburetors, slightly steeper
steering geometry, and a taller final-drive ratio. And, like the 600, its most
significant feature is the incorporation of liquid cooling.
Almost 3 quarts of coolant circulate through the engine and a
curved, 13-by- 15-inch radiator, pushed through the engine's water jackets by an
externally mounted waterpump driven from the oil-pump shaft. Suzuki says that
optimal operating temperature is 170 degrees Fahrenheit, and that an electric
fan switches on if coolant temperature reaches 220 degrees.
Thanks to the new cooling system, the engine's oil is called on
to handle less of the heat-dissipation chores, so a single-stage oil pump
replaces the dual-stage unit used on previous GSX-Rs. Gone is the oil radiator;
engine oil now passes through a liquid-cooled oil cooler built into the
oil-filter base. As with previous designs, though, oil is sprayed on the
undersides of the pistons. Suzuki claims a combined cooling capacity twice that
of the old powerplant.
The oversquare, 70.0 x 48.7mm bore-and-stroke dimensions of the
previous engine have been retained, as have 38mm Mikuni CV carburetors, although
the new bike's carbs don't include the powerjet circuit used on later GSX-R750s.
As on the GSX-R600, Suzuki adopted a shim-under-bucket valvetrain design for the
750, which allows the camshaft lobes to act directly on the valves without the
use of rocker arms, resulting in better valve control at high rpm.
Valve-adjustment intervals have been increased from 3500 to 7500 miles, and the
traditional 600-mile valve-lash service has been eliminated.
Included valve angle has been reduced to 32 degrees from the
previous motor's 40 degrees, and the compression ratio is up from 10.9:1 to a
sky-high 11.8:1. The new 750 uses lighter pistons and narrower-stemmed valves,
with intake tracts that have been reshaped and shortened. And the cam timing,
the carburetor jetting and the 4-into-2-into-l exhaust system all have been
revised.
This new motor also is substantially smaller and more compact
than previous GSX-R designs. The crankshaft has been shortened, cylinder pitch
has been reduced, and the starter clutch has been relocated to accompany the
alternator behind the cylinders. The new cylinder head-which still utilizes
Suzuki's Twin Swirl Combustion Chamber-is smaller as well, thanks to the tighter
valve angle, narrower cylinder placement, more compact valvetrain, shorter
camshafts and elimination of two camshaft journals, one per side.
With a more compact powerplant, Suzuki was able to relocate the
engine farther forward and lower in the chassis. This improves front-wheel
weight bias and lowers the bike's center of gravity without sacrificing
cornering clearance.
Like the engine, the chassis has been thoroughly revised, though
the similarity in appearance to previous GSX-RS was maintained. The aluminum,
double-cradle frame now features pentagonal-cross-section main spars, which,
according to Suzuki, increase torsional rigidity by five percent. The
asymmetrical aluminum swingarm also is new and is claimed to be more rigid than
its predecessor. Following grand prix fashion, the arm's right side is arched,
allowing the exhaust canister to be tucked in tighter for additional cornering
clearance. To ease maintenance and crash repair, the aluminum rear subframe,
previously welded on, is now removable.
Compared to the old 750, steering geometry has been quickened by
reducing rake to 24.5 degrees from 25.5 and shortening trail to 3.7 inches from
3.9. Some of the highspeed stability that might have been lost as a result of
the quicker geometry has been retrieved by lengthening the bike's wheelbase 0.75
inch. A non-adjustable hydraulic steering damper helps guard against headshake.
The 750's suspension mirrors that found on the GSX-R600. A fully
adjustable, inverted, cartridge-style 41mm Showa fork is mounted up front, while
a Showa shock with similar adjustments and a remote reservoir is fitted at the
rear. Both fork and shock springs have been altered, as have the fork's damping
rates. In addition, the shock linkage has been revised for more progressive
action. Tires are Dunlop D202 Sport Radials in 120/70ZR17 and 170/60ZR17 sizes
mounted on 3.5- and 5.5-inch wheels, respectively.
Enough about the bike's mechanical makeup; we traveled 2100
miles to see what this new GSX-R is like to ride, especially around
Shann4onville's twisty, bumpy road course. But first, to get to the track, we
had to complete a two-hour freeway drone, during which the new GSX-R reminded us
of the GSX-R600. Both have uncompromising seating positions, near-vibration-free
engines and taut-feeling suspensions.
Like the 600, the new 750's seat-to-handlebar distance has been
increased, while the seat-to-footpeg measurement has been taken in. You won't be
doing much casual touring on this 750. The engine warms quickly and the
bar-mounted choke can be thumbed off within a half-mile. Vibration is almost
non-existent below 7500 rpm, with only a slight buzz felt through the clip-ons
and footrests. Above that mark, vibes increase a bit, but are never obtrusive.
At Shannonville, we tested the two GSX-Rs back-to-back, and the
results were surprising. In 40-to-60-mph top-gear roll-ons, the year-old model
smoked the liquid-cooled bike by a full second, likely due to its crisper
bottom-end carburetion. In the 60-to-80-mph runs, the tables were turned, with
the '92 model overcoming its 3800-4200 rpm lean spot and recording a slight
advantage over the air-and-oil-cooled bike. But quarter-mile acceleration again
went to the '91 GSX-R, which outgunned the '92 by over a tenth of a second
(11.37 seconds at 116 mph compared to 11.51/117). At first, we thought the new
bike's performance dip could be attributed to its marginally taller final
gearing, but a check of the charts showed that the two bikes' overall gear
ratios
Suzuki claims 118 horsepower at the crankshaft for the new
engine. We were unable to perform our normal dynamometer testing in Canada, but
Cycle Canada magazine had just finished its road test of the very
GSX-R we were riding, and it recorded 100 horsepower at 10,800 rpm, with a
torque peak of 51 foot-pounds at 9000 rpm. This was on a Dynojet rear-wheel
dyno, the same kind of dyno Cycle World uses. The 1992 U.S. 750 we
tested earlier this year put out 104.5 horsepower and 54.8 foot-pounds of
torque. Taking into account the variables of different dyno locations on
different days, it is nonetheless apparent that the liquid-cooled GSX-R is no
more powerful than the air-and-oil-cooled unit it replaces.
At least the new motor pushes the aerodynamically cleaner
liquid-cooled GSX-R to impressive velocities. Cycle Canada radar-gunned our test Suzuki at 158 mph. That's 8 mph faster than the U.S.
version, and easily makes the GSX-R the fastest production 750 to date. In fact,
it's only 1 mph slower than the 1992 GSX-R1100.
Throughout the day, engine temperature remained moderate, the
gauge's needle never passing halfway in the normal operating range. Competition
System's Mike Crompton noted that the new cooling system works so well that
Canadian race tuners have been taping over portions of the radiator in an effort
to increase engine temperature.
Steering was precise and required less effort than the old-style
model. Even with the reduced steering-head angle, the new GSX-R felt more stable
than last year's bike, especially under hard braking. Fork action was near
faultless, allowing the front wheel to track beautifully over Shannonville's
many ripples. The shock, however, wasn't quite up to the same high standards.
After a full day of riding, rebound damping faded to the point that the adjuster
had to be cranked up to the maximum of its four settings. Racers will likely
replace the damper with an aftermarket unit; most street riders will be happy
with the stock setup.
Though the rear suspension's damping qualities left something to
be desired for hard riding, we found the revised rising-rate linkage to be a
real improvement. Last year's design offered softer initial reaction to bumps,
but became suddenly harsher farther into the travel. The new link is more linear
and provides a more compliant overall ride.
The Nissin four-piston calipers and 12.4-inch discs also
performed well, offering consistent, fade-free stopping. The 9.6-inch rear disc
and its twin-piston caliper, though, were overly sensitive and caused the rear
tire to chatter under hard use. The stock Dunlop D202 Sport Radials, though not
the company's premium-grade sporting rubber, worked well at Shannonville, and
only began to lose their grip late in our track session. And even then, slides
were very predictable and easy to control.
Is the liquid-cooled GSX-R the ultimate 750 sportbike? Tough
question. Its. chassis is first-class, no doubt, but the new engine is no more
powerful than the previous air-and-oil-cooled design. And though Suzuki should
be commended for adding liquid cooling without increasing weight (we didn't have
access to a scale in Canada, but the bike should be very close to the
old-style's 484-pound dry weight), the latest-generation GSX-R tips the scales
with about 60 more pounds than the original 1985 GSX-R750. Not very impressive
in this post-CBR900RR era-the new Honda weighs-in at 432 pounds dry.
But the good news is that the liquid-cooled bike has a better
chassis and is better-handling than the old bike. And, more importantly, the
cooling system seems to have been overengineered for street use, which means
race tuners should be able to tweak the motor to their heart's content and not
worry about burning the thing down to its base gasket. Factor in the more
slippery bodywork, and Suzuki should once again be a force to be reckoned with
in production-based roadracing.
There's more good news on the price front. Despite American
Suzuki's early fears that the liquid-cooled bike would be overpriced, it is
currently on sale in Canada for the equivalent of $6800, just $100 more than the
U.S. air-and-oil-cooled version. Even if a few hundred more dollars get tacked
on for 1993, Suzuki shouldn't suffer in the showroom.
So, this newest GSX-R offers no great technological leaps
forward. But for Suzuki, it is a very big step in the right direction.
Source Cycle World 1992
Make Model | Suzuki GSX-R 750WP |
---|---|
Year | 1993 |
Engine Type | Four stroke, transverse four cylinder, DOHC, 4 valves per cylinder. |
Displacement | 749 c / 45.7 cub. in. |
Bore X Stroke | 70 x 48.7 mm |
Compression | 11.8:1 |
Cooling System | Liquid cooled |
Engen Oil | Synthetic,10W/40 |
Exhaust System | 4-into-2-into-1 Stainless-steel exhaust |
Lubrication | Wet sump |
Induction | 4 x 38 mm Mikuni BST38SS carburetors |
Ignition | Computer controlled electronic ignition |
Spark Plug | NGK, CR9EK |
Starting | Electric |
Max Power | 88 kW / 118 hp @ 11500 rpm |
Max Power Rear Tire | 80.4 kW / 107.8 hp @ 11200 rpm |
Max Torque | 80 Nm / 8.2 kgf-m / 59 ft-lb @ 10000 rpm |
Clutch | Cable operated, wet multiple, coil spring |
Transmission | 6 Speed, constant mesh |
Final Drive | #530 Chain, O-ring sealed, 108 links |
Gear Ratios | 1st 2.77 / 2nd 2.25 / 3rd 1.65 / 4th 1.40 / 5th 1.23 / 6th 1.09:1 |
Frame | 5-sided aluminum pipe frame with sand-casted steering head section and cast swing arm pivot |
Front Suspension | Showa 41 mm cartridge style upside-down forks, preload, compression and rebound adjustable |
Front Wheel Travel | 120 mm / 4.7 in. |
Rear Suspension | Full floater, preload, compression and rebound adjustable |
Front Brakes | 2 x 310 mm Discs, 4 piston Nissin calipers |
Rear Brakes | Single 240 mm disc, 2 piston Nissin caliper |
Wheels | Alloy, 3 spoke |
Front Rim | 3.5 x 17 |
Front Tire | 120/70 ZR17 |
Rear Rim | 5.5 x 17 |
Rear Tire | 170/60 ZR17 |
Rake | 24.5° |
Trail | 94 mm / 3.7 in. |
Wheelbase | 1440 mm / 56.7 in. |
Dimensions | Length 2070 mm / 81.5 in. Width 730 mm / 28.7 in. Height 1135 mm / 44.7 in. |
Seat Height | 790 mm / 31.1 in |
Dry Weight | 208 kg / 458.6 lbs |
Wet Weight | 234 kg / 516 lbs. |
Fuel Capacity | 21 Liters / 5.5 US US gal / 4.6 Imp gal |
Average Consumption | 7.1 L100 km / 14 km/l / 32.9 US mpg / 39.8 Imp mpg |
Braking 100kmh - 0 / 60 Mph - 0 | 36.7 m / 120.4 ft |
Braking 60 Kmh - 0 / 37 Mph - 0 | 12.9 m / 42.3 ft |
Standing ¼ Mile | 10.7 sec / 206 km/h / 128 mph |
Top Speed | 257.9 km/h / 160.3 mph |
Colours | White/Blue, Red/White |
Source | Cycle World |