Stealth Superbike
STEALTH SUPERBIKE
This Yoshimura Suzuki GSX-R1000 can be anything you want it to be
BLAKE CONNER
SOMEONE PLEASE TAKE THIS TOY AWAY from me before I get in trouble! Those were my thoughts after a week of commuting on this Yoshimura-built GSX-R1000 and glancing down at the speedo on the freeway one morning, realizing that triple digits could send me to jail. The bike was assembled to showcase the many go-fast parts that the Yoshimura Race Shop (www.yoshimuraraceshop.com) division of the Japanese company had to design, build and homologate in light of the new 2009 AMA Pro American Superbike regulations.
It doesn’t matter how many rules the Daytona Motorsports Group and the AMA make to American Superbike racing, the best riders and best teams are always going to rise to the top and win. Take this past season of competition, for instance: Despite plenty of controversy, dumbed-down Superbike rules and a few ruffled feathers along the way, Rockstar Makita Suzuki’s Mat Mladin and his Yoshimura GSXR1000 undoubtedly proved to be the class of the field by taking a seventh AMA Superbike title. To quote Lance Armstrong: “It’s not about the bike.”
Or is it?
There is definitely an advantage to being on a well-sorted machine, as Associate Editor Mark Cernicky and I discovered after spending a day aboard this near-Superbike-spec sleeper GSXR1000 at a Fastrack Riders (www.fastrackhders.com) track day at California Speedway in Fontana. For comparison, we brought along our bone-stock ’09 GixxerThou’ fitted with sticky Bridgestone BT-003 rubber. Riding the two Suzukis back-to-back, we both easily ran lower lap times on the Yoshimura bike than we ever would have achieved on the stocker. So, in reality, yes, the machine can make a huge difference. But Superbike-racewinning glory it can’t provide, at least for us; only a wish granted by a genie in a bottle could provide that.
One key element of the 2009 AMA Superbike rules was to make aftermarket parts available for every competitor in the series (and, in turn, the general public). The theory was that this would level the playing field and eliminate the advantages that the factory teams have enjoyed for decades, and therefore provide closer racing. Now, anyone in the paddock can purchase the same parts off the Eligible Equipment List and build a motorcycle that is-at least in terms of its ingredients-made from the same recipe as, say, Mladin’s championship-winning bike. Then it’s simply up to the chef to make a masterpiece. Obviously, this is easier said than done because careful assembly and tuning still count for a lot. Just ask Mat’s competition!
Suzuki and Yosh have been tied at the hip since 1978, and in that time they have amassed 24 AMA roadracing titles (13 in the Superbike class), not to mention a whole lot of knowledge about GSX-R motorcycles. The beauty of the new rules is that whether you are a sportbike junkie looking for trick parts, a track-day rider seeking more thrills or a privateer racer trying to knock another second off your lap times, you can find most of what you need in Yoshimura’s Book of Speed. You can then mix-and-match parts to accomplish your performance goals. The question boils down to how much money are you willing to spend for that extra speed.
It may be a stretch to call a modern, lOOOcc inline-Four a “sleeper,” but amongst like peers, this black GSXR1000 is definitely flying stealth. On the street, the bike looks like any other sportbike equipped with an aftermarket exhaust, raising no red flags. But at California Speedway, it was obvious that the bike was special, peeling the paint off of other more standard liter-
classers (Rls, ZX-10Rs and CBRs) as it ripped around the banking hitting an indicated 192 mph before braking for Turn 1. Optimistic speedometer? More than likely, yes, but wickedly fast, no matter the calibration error.
The engine received a healthy dose of Yoshimura parts, which let loose 17 additional horsepower over our stocker and a couple added kicks of torque, too. The Type R cams ($945) offer 0.4mm more intake lift and slightly less duration (258 degrees intake,
250 degrees exhaust) than stock for improved midrange. A thinner head gasket ($172) bumps the compression ratio up to 12.9:1 (from 12.8). A BMC race air filter ($86), 8.7 pound R-77 Titanium full-race exhaust with carbon-fiber silencer and end cap ($1799 and 18.5 pounds lighter than stock!),
and the EM Pro ($1603) engine-management computer were all optimized for 91-octane pump gas. The $4605 worth of goodies yielded 1 76 horsepower and 78 foot-pounds of torque at the rear wheel on the Cycle World dyno.
Impressive peak numbers for sure, but you can’t have it all when it comes to tuning, so sub-6000-rpm power output suffers in order to gain all that oomph above 10 grand. But while bottom-end power figures may be lower than those of the stock bike, that doesn’t mean that the manner in which the power is delivered has to suffer. Thanks to the widely tunable EM Pro computer, low-rpm civility is excellent. And, in fact, the maps are near-perfect across the rev range.
At the track, throttle response was impeccable; idling through the pits or picking up the throttle exiting tight corners, the engine did exactly what we asked of it. More surprising was how perfectly civilized the bike was around town in everyday riding; it started, idled and ran without a hiccup, hot or cold. The S-DMS mode selector still works within the same parameters, so A, B and C maps function as stock, allowing the rider to select power curves to suit conditions.
Acceleration is impressive, helped no doubt by shorter final-drive gearing of 16/42 (one less tooth on the countershaft sprocket) and a lighter-weight RK 520 chain conversion.
Helping to lay down the added power-especially considering that Yosh fitted the bike with a set of AMA-series-spec Dunlop slicks-are several chassis upgrades. At the rear, repositioned inserts ($295) move the swingarm pivot up 2mm in the frame to steepen the swingarm angle (relative to the ground), which improves rearwheel traction and keeps the bike from squatting under power. It also helps maintain chassis composure because at maximum cornering load, the swingarm approaches but doesn’t typically pass horizontal, maximizing the effective wheelbase for added stability. A 159mm (17mm longer) suspension linkage ($485) has a more linear rate to improve suspension action during high cornering loads. This link mates to a Showa “kit” shock ($1650) that features an external hydraulic preload adjuster and is equipped with a rideheight-adjustment kit. AMA rules stipulate that the fork must retain the stock internal and external tubes, so Yosh revalved the unit in-house (although an $1800 Öhlins cartridge kit is available). An interesting addition are the Fork Cap Extenders ($265) that allow the front end of the bike to be raised an additional 25mm if desired. Brakes are upgraded with Galfer 1375 pads ($40) at the front, as well as stainlesssteel braided lines front ($100) and rear ($54).
After our first session on the track, it was a surprise to find the bike was steering like a cement truck, so we ignored the added range of the forkcap extenders and dropped the front by 3mm and also added a 3mm shim to the rear ride-height adjuster. These changes, in addition to the fact that the bike weighs 24 pounds less than stock (404 pounds dry), allowed the GSX-R to snap down to the apex much easier, especially through Cal Speedway’s fourth-gear, Turn 1 chicane. Stability was still quite good through all but a few sections of track, where the bike was trying to wheelie and would shake its head when on-throttle.
Another change we made was to adjust the Yoshimura rearsets ($475), which picky Cernicky couldn’t get comfortable with. The new positioning was only barely tolerable for me but did allow the “fanatic of fit” to rip off a very respectable 1-minute,
32.182-second lap time, 2.1 seconds quicker than he achieved on the DOT-equipped stocker.
Mladin’s 1:23.749 fast lap from the spring AMA race was safe, but Cernicky’s lap time on a bike with stock bodywork, headlight, taillight, rear turnsignals and the rest of its street gear (sans mirrors) is impressive. You can even honk the horn!
Other nice touches-most of them designed to prevent damage in a crashinclude chassis protectors ($50), case savers ($195), billet bar ends ($30) and rear stand spools, all aluminum and anodized a nice bronze color.
So, unless you’ve been reading with your abacus handy, the total list of upgrades adds up to approximately $8500, in addition to the $12,899 price of a new 2009 GSX-R1000. This is by no means cheap, but considering that this bike can be had for less than the price of a Ducati 1198S or an MV Agusta F4 1078RR while pumping out serious power, handling like a true racebike and running as docilely as a stocker around town, it suddenly seems worth every penny.
With the bike about to be snatched back by Yoshimura, I’m going to have to eat my own opening words: Please don ’/ take this bike away! On the bright side, Yoshimura USA head man Don Sakakura and his team are taking the bike back to the Chino race shop for some additional upgrades. Fortunately, their plan to convert the bike into a fullblown Superbike involves us getting to throw a leg over our old friend once again in the near future. Now if I could only find that damn bottle with the genie in it!
cycleworld.com/yosh I MORE PHOTOS YOSH GSX-R1 000
