2008 Suzuki GSX-R750 Test - Lone Wolf

For being the only fish in the three-quarter-liter pond, the GSX-R750 sure gets a lot of attention from Suzuki to stay sharp. You'd think that as the last 750 sportbike left standing it would have the right to rest on its laurels and enjoy some well-deserved leisure time. Let the 600s and literbikes work themselves into a froth every two years; the last-generation GSX-R750 certainly wasn't a slouch ("Ahead of the Curve," Dec. '06), and with no direct competitors for almost a decade, you couldn't blame Suzuki if it'd just plastered some new graphics on the '08 version and called it good.

The GSX-R750 is very dear to the corporate hearts at Suzuki management, however, and they're not about to let the model that stamped the company's name indelibly on motorcycling history back in 1985 grow moldy and be mothballed in the back section of the company catalog. Thus the GSX-R750 has enjoyed a frequent-upgrade schedule over the years that easily rivals that of its 600 and 1000 stablemates.

And we're all the better for it. Suzuki's constant tweaking of the GSX-R750 has resulted in a sportbike offering a superb balance of power and handling that in the right hands will often put its bigger and smaller brethren to shame on both street and track. This thankfully hasn't gone unnoticed by the sportbiking public; unit-sales numbers for the 750 were close behind the 1000 (which already enjoyed healthy sales) last year.

Subtle Refinement
With no real reason to turn the applecart upside down, Suzuki engineers concentrated on minor modifications to increase performance while also dealing with ever-stricter emissions and noise regulations. Interestingly, many of the engine changes were aimed at shoring up the sagging midrange that appeared to plague the previous-generation GSX-R750 on the dyno but not on the road (at least as far as we could tell).

For starters, the intake-cam profile now features reduced lift specs to improve that midrange power. Aggressive high-lift cams can help produce good top-end power, but intake velocity drops at lower rpm, compromising cylinder filling. By tweaking other aspects of the intake system along with the lower-lift cams, you can maintain the same top-end power while enhancing the midrange.

The twin double-barrel SDTV (Suzuki Dual Throttle Valve) throttle bodies' primary and secondary injectors now each have eight smaller holes instead of the previous units' four large ones for better fuel atomization. Assisting in this regard is a more powerful engine-management system operating the secondary throttle valve more precisely to maintain high-intake velocity, with the primary injector taking advantage of this by being positioned at a steeper angle to spray deeper into the intake port.

The more powerful engine-management system also controls the updated ISC (Idle Speed Control) system fitted to the throttle bodies. The ISC not only manages idle speed by regulating intake flow through a bypass circuit via a stepping motor (including cold-start fast idle), but we also think it assists the slipper clutch in reducing engine back torque by increasing idle during heavy braking. The slipper-clutch unit itself has a different drive-cam shape and new clutch-plate material to work with the revised setup. And to minimize mechanical noise, new internal ribbing inside the clutch cover and oil pan helps cancel out resonance. Another feature made possible by the more powerful ECU is the addition of the S-DMS (Suzuki Drive Mode Selector) with three different maps, which is already found on nearly all Suzuki sportbike models now.

The increased breathing capabilities of the engine meant that a new larger, triangular cross-section muffler was needed in order to add internal volume while still quelling exhaust noise. Header-pipe diameter was decreased to 35mm to optimize exhaust-pulse scavenging for improved power output in the low-end and midrange rpm, and the SET (Suzuki Exhaust Tuning) valve remains in the collector leading to the underengine exhaust chamber to reduce noise and improve low-end power.

On the opposite end of the engine, the ram-air intakes have been repositioned as close as possible to the center of the fairing nose, where pressure is the highest. An internal louver system in the ram-air ducts reduces debris intake while smoothing airflow for increased efficiency by removing the previous screens at the duct entrances. New 10mm NGK spark plugs feature an iridium-alloy electrode that produces double the spark energy of a conventional plug.

On the chassis side, the rear subframe is now a lighter and simpler single-section die-cast unit instead of the previous piggyback construction, saving 125 grams of weight. A new Showa 41mm inverted fork features spring preload, rebound damping and both high-speed and low-speed compression-damping adjustments to complement the rear shock that sports the same adjustability. The steering damper attached to the lower triple clamp now has electronically controlled damping similar to the GSX-R1000 unit.

New die-cast aluminum-alloy wheels are lighter and more rigid thanks to a new offset/curved three-spoke design. OEM-spec variants of Bridgestone's superb new BT-016 tires are fitted on both ends. The 310mm front-brake discs use four additional floating pins per rotor (now 12) to promote heat dissipation and prevent heat distortion of the discs, and disc thickness is decreased from 5.5mm to 5.0mm. The front-brake radial master cylinder piston was made smaller (from 19.05mm to 17.0mm) for better response.

Unfortunately, as per the trend during the past few years with ever-tightening emissions regulations worldwide, the latest GSX-R has gained a few pounds. Our test unit tipped the scales at 447 pounds full of fuel, an increase of seven pounds over last year.

The Best Of Both Worlds
Despite the updates to the EFI and engine-management system, the latest GSX-R750 retains the previous model's cold-blooded temperament (perhaps even more so) when taking off in the morning, with an off-idle fluffiness that requires some throttle manipulation to get through cleanly. Once the engine warms up to normal operating temps, however, the issue disappears, and throttle response down low becomes much better. Controls are basically identical to last year, so the same stylish but less functional mirrors remain, with limited adjustment forcing you to pull in your elbows to see directly behind you. Even that won't do much good while cruising on the highway, as the mild vibration that creeps into the footpegs (still adjustable in three positions) and bars from 4000 to 6000 rpm fuzzes out the images enough that you won't be able to tell whether that's a state trooper or taxicab behind you until it's too late.

The same bit of driveline lash and notchy-shifting transmission makes itself known during around-town riding, although it quickly disappears once the speed and pace pick up. Wind protection from the slim fairing and racy windscreen is still surprisingly good, and fuel consumption on the street never dropped below 38 mpg even with plenty of aggressive riding.

Where the big difference between the '08 and last year's model makes itself known is the instant you get on the throttle anywhere below 9000 rpm. Although we didn't exactly find the previous GSX-R750's power to be flaccid below that point, it pales in comparison to the new model's much stouter midrange pull. You may not be outrunning any literbikes in highway roll-ons, but a graphic example of the new 750's stronger midrange is that it absolutely stomps the old model in the 60-80-mph and 80-100-mph roll-on tests. The new model took only 3.28 seconds to run from 60 to 80 mph (compared with 3.59 seconds for the old GSX-R) and basically leaves the old Gixxer for dead from 80 to 100 mph, requiring only 3.63 seconds to cover that speed. The gap between that and last year's 4.26-second measurement is a comparative eternity in roll-on terms. And no, overall gearing was not a factor in the '08 Suzuki's newfound speed, as there were no changes to internal gear ratios and both models cruise at around the same engine speed (5500 rpm) at 70 mph in top gear.

The new 750's power spread is far smoother and easier to access than before, and there's no longer a big dip at 5500 rpm, meaning you can let the revs drop and not be punished for it as you would on a 600. There's simply more power available practically everywhere in the lower rpm ranges, and the friendlier character translates to a much easier time generating speed in any cornering situation you can think of.

But the emphasis on midrange rpm power hasn't exactly stunted the '08 GSX-R's top-end charge. Suzuki introduced the new model to the press at Willow Springs' ultrafast 2.5-mile main road course, where a bike that doesn't have the right combination of handling and top-end power is a sitting duck. We have to admit we were astounded at the new GSX-R's ability to leap off the exits of Willow's faster corners and the voracity with which it inhaled the straights. Don't let the dyno chart's peak power number fool you; while the new GSX-R's 123.1- horsepower reading may be down significantly from last year's 129.1-horsepower measurement, it should be noted that our SuperFlow dyno's updated software during its recent move (the previous-generation GSX-R test was done long before then) has resulted in slightly lower peak numbers on average. There is also the aspect of the redesigned ram-air intakes that have done away with the wire mesh screens on the intake mouths. We once did some top-speed testing with an older-generation GSX-R750 back in 2000 and found that removing the screens resulted in a consistent increase of nearly 2 mph on top, which is a significant power jump at those speeds (and won't be present in static dyno readings). While there's no doubting that the peak power of the '08 GSX-R is down a bit from previous years, we feel that unless you're an expert rider searching for that last tenth of a second, the smoother and stronger midrange powerband generates enough additional corner speed (translating to added mph off the corners) to offset that deficit.

Contributing to that cornering ability is the same superlative chassis from the previous generation that offers up 600-class turning agility with near-telepathic feedback from both ends. The amount of effort required to flick the 750 into a corner compared with a 600 is negligible, and the 750's power advantage means it not only isn't as demanding to ride, but also more capable in skilled hands. Even though the new Showa 41mm inverted fork isn't head and shoulders above the old unit in terms of performance (and it's not like the old fork was lacking anyway), we found the new high-speed compression damping adjustability to be a plus, allowing us to fine-tune its manners under aggressive cornering and braking. And being fitted with an OE-spec version of Bridgestone's marvelous new BT-016 sport tires is certainly another plus, contributing to the 750's precise and responsive steering.

Speaking of braking, the 750's binders still remain our favorites in the GSX-R lineup. They not only possess superb power, feel and progressiveness when used aggressively in the canyons or on the racetrack, but they maintain a crisp response at slower speeds on the street, especially during the first few miles on a cold morning.

Our experiments with the S-DMS modes had us returning to the full-power A mode and leaving it there. The B mode causes too much of a delay in acceleration response, forcing you to twist the throttle more than necessary, and then full power arrives too late. The C mode just makes the GSX-R feel slower than an SV650.

The Perfect Balance
The term "balance" is being thrown around a lot lately in the sportbike world. In an era of ever-higher horsepower outputs and sharper, race-inspired chassis demanded by the market, manufacturers are finding it increasingly difficult to keep one aspect from overpowering another. But the GSX-R750 continues to showcase that elusive combination of power and handling capable of making serious time down a canyon road or on your favorite racetrack with a lot less effort than either a 600 or literbike.

Every time we've brought the three-quarter-liter Suzuki along for a ride with other sportbikes, it's ended up being the one we agree on as the most fun to ride. And it continually baffles us that the other manufacturers don't see this class as having any potential in the sportbike market, despite the sales numbers of recent years-and the sales numbers of the category back in the early '90s when it was the showcase class for all the factories.

With a class of one and nothing to directly compare it with, it can be difficult to show just how good a modern 750 can really be. But we're going to be putting the new Suzuki GSX-R750 up against some very capable sportbikes in the near future to see how it really stacks up. Stay tuned.

'08 Suzuki GSX-R750
Test Notes
+ Stronger midrange
+ Same superb chassis, brakes
+ Superb stock rubber
- Slight loss of top end
- Gained some pounds
- S-DMS not really practical
x Despite its flaws, still the best all-around sportbike displacement-um, didn't we say that last time?

Suggested Suspension Settings
Front
Spring preload: 9 turns out from full stiff; rebound damping: 0.5 turns out from full stiff; high-speed compression damping: 2 turns out from full stiff; low-speed compression damping: 2.5 turns out from full stiff; ride height: 10mm fork tube showing above triple clamp

Rear
Spring preload: 8mm thread showing from top of spring collar; rebound damping: 1.5 turns out from full stiff; high-speed compression damping: 3 turns out from full stiff; low-speed compression damping: 4 turns out from full stiff

'08 Suzuki GSX-R750
MSRP: $10,599

Engine
Type: Liquid-cooled, transverse, inline 4-stroke four
Valve arrangement: DOHC, 4 valves/cyl., shim-under-bucket adjustment
Displacement: 749cc
Bore x stroke: 70.0 x 48.7mm
Compression ratio: 12.5:1
Induction: SDTV EFI, 42mm throttle bodies, 2 injectors/cyl.
Transmission: 6-speed

Chassis
Front suspension: 41mm inverted cartridge fork, 4.7 in. travel; adjustments for spring preload, high- and low-speed compression damping, rebound damping
Rear suspension: Single shock absorber, 5.1 in. travel; adjustments for spring preload, high- and low-speed compression damping, rebound damping
Front brake: Two 4-piston calipers, 310mm discs
Rear brake: Single-piston caliper, 220mm disc
Front wheel: 3.50 x 17 in.; cast alloy
Rear wheel: 5.50 x 17 in.; cast alloy
Front tire: 120/70ZR-17 Bridgestone BT-016F E
Rear tire 180/55ZR-17 Bridgestone BT-016R E
Rake/trail: 23.8 deg./3.8 in. (97mm)
Wheelbase: 55.1 in. (1400mm)
Seat height: 31.9 in. (810mm)
Fuel capacity: 4.4 gal. (16.5L)
Weight: 447 lb. wet (203kg); 420 lb. dry (191kg)
Instruments: Analog tachometer, LCD panel for gear indicator, S-DMS, coolant temp, odometer/dual tripmeters/clock/fuel reserve; warning lights for neutral, high beam, turn signals, EFI problem, shift point

Performance
Roll-ons: 60-80 mph/3.28 secs.; 80-100 mph/3.63 secs.
Quarter-mile: 10.26 secs. @ 137.53 mph (corrected)
Top speed: 170.3 mph
Fuel consumption: 38-47 mpg, 42 mpg average

Opinions

Troy Siahaan
I want to be just like Andrew Trevitt
There are certain bikes out there that just make sense. For me the GSX-R750 is one of those bikes. It's got more grunt than a 600 so I'm not always screaming the little engine, but it's not making the freakish horsepower the literbikes pump out. Whenever I twist the throttle on this bike I'm not holding on for dear life, nor am I waiting for the engine to wail past 10 grand. It's got just the perfect blend of acceleration that my feeble brain can handle. Add in the fact that it feels as small as and changes direction like a 600, and I gravitate toward it more and more every time. Thank you to the powers that be at Suzuki for sticking with tradition and keeping this bike alive (and updating, too!). If ever there was a real-life example of less being more, the GSX-R750 is it.

Andrew Trevitt
The next American Idol
It seems to me that with every iteration the GSX-R750 gets closer to being what you'd expect-and want-it to be: a GSX-R600 with a lot more power. Just as we've found before, the 750's chassis components are all slightly higher-spec than those on the 600, and each works accordingly better by a noticeable degree. But whereas those bits couldn't quite bridge the handling gap between the two bikes in years past, now they do: On the same roads we just finished testing all the 600s and 1000s on, I thought the 750 handled every bit as well as any of them.

The last time we tested a GSX-R750 I hinted in my SRO that Suzuki had it easy with no competition in the class and that the GSX-R would have trouble if Yamaha, for example, were to build an R7 again. The '08 model nicely addresses what few complaints we had with the old bike, and it's fitting that the issue with that old test (Dec. '06) is sitting on my desk. The cover blurb asks the question, "Best sportbike ever?" I can't wait for this year's Bike of the Year test to find out.