Ya gotta love a survivor. Despite the performance parity between the latest crop of Japanese literbikes, Suzuki's two-year-old, third-generation GSX-R1000 has managed to remain atop the ultra-competitive superbike heap, if only by a slim margin. It's sicko fast, it handles well, it's plenty durable, there're a bazillion aftermarket parts available for it, and last but not least, it's won a slew of AMA Superbike champion-ships. 'Nuff said.
Because the big Gixxer has become the literbike of choice for untold thousands of street riders, racers and track-day enthusiasts, we figured we'd ask an expert-Danny Hull, AMA and World Superbike tuner to the stars-to outline the most effective tweaks for Suzuki's blue-and-white beast. Here's what he had to say.
Tires and wheels
"We recommend and use Dunlop because the shop is Dunlop's Western U.S. track supplier," Hull says. But there are plenty of excellent tires out there, whether slicks or DOTs. "The key," he adds, "is to pick a tire, develop your chassis around it, and then stick with it. Tires are constructed differently, and going from brand to brand will wreak havoc on a good chassis setup." Hull says the stock wheels are excellent for street or track-day work. "Aftermarket wheels are lighter, but they're considerably more fragile, too; they're often toasted in a crash, and they're very expensive."
"We recommend a remote-reservoir hlins shock, which is about as good as you can get," says Hull. "For a 180-pound rider we recommend an 8.5 kg-m spring with 28mm of sag. This is a good starting point." Hull says having your GSX-R's stock shock revalved and, if necessary, resprung by firms such as Lindemann Engineering is an OK way to go. "But the key," he says, "is to do the fork and shock together and then properly dial them in. Doing only one system will overcome the other."
"It doesn't need much," Hull says. "A high-end exhaust and a programmable intake system gives 170-plus rear wheel horses, which is a lot." Those wanting more can degree the cams, mill the head (or cylinders) and maybe go with a big-bore kit and cylinder-head porting-though Hull cautions about reduced durability with such advanced tweaks. Be sure to use a reputable shop for high-end modifications. "Today's literbikes are so powerful right out of the box, you don't really need to do more than the basics. I'd focus on suspension setup and tires. They mean everything."
"For us, race-spec clip-ons with two or three pinch bolts each [most stockers have just one] and a wide range of adjustability for additional steering leverage are a must," Hull says. He also recommends installing more restrictive steering stops, which limit movement to just 18 degrees for each side. "When it slaps, the rider can hang on; with 70 or 80 degrees of movement, the bars can get ripped out of a rider's hands, and even break a rider's thumbs! Stock stops can also make the bike highside since the flapping front end can allow the back end to step out more." Adjustable rearsets are also useful, and give the rider better footing.
"We've had great luck with Yoshimura's full-titanium TRC system," Hull says. "I feel it's the very best system out there because it's been developed and proven on the AMA Superbike circuit." Whether you go with a full system (expensive) or a slip-on (less so), you'll need to re-map the fuel injection to suit with an adjustable FI mapping system. "You want the mixture to burn white at the tip of the muffler; we call it 'snowballs from hell'; it's proof of optimum mixture." See our October issue's Garage section for the story on how this works.
"The stock fork is fine for the street," Hull says, "but for track-day or race use it demands higher-quality internals. We use hlins' drop-in fork kit, which is expensive [approximately $1800], but which totally transforms the fork and allows us to make minute changes in damping settings." Myriad aftermarket companies offer fork kits and modifications to upgrade your stock fork assembly; pick a reputable firm if you choose this path. "Don't automatically think you need firmer springs," Hull cautions. "For a 180-pound rider we recommend .95 kg-m springs, with sag set at 38mm. Remember, you want the fork-or shock-to use all its travel, not bind up with too much preload or damping."
"For the street or track days, the stock setup is darn good," Hull says, "especially with firmer steel-braided brake lines. We use the stock pads even when we're racing; they're excellent, though we do experiment on occasion. We use Galfer aftermarket rotors in Formula One competition at Willow Springs; they offer more bite than the stock rotors, which the rider can use to good effect."
Once you increase exhaust flow with an aftermarket exhaust, you'll need to increase and optimize the amount of fuel the injectors are squirting into those fiery combustion chambers. Hull recommends-and uses-Dynojet's Power Commander, though Cobra's FI2000 system also does the job. "With the Power Commander, you can tweak the mixture in 500-rpm increments," he says, "although visiting an official Power Commander shop allows you to do it in even finer increments, which is key when you're dialing in a racebike for ultimate top-end power."