Sometimes we just can't help ourselves. It began two years ago when Corey Neuer, test editor at our sister publication Dirt Rider, bought a GSX-R600 and started club roadracing. Soon after, we could count on Neuer showing up on our side of the motorcycle group's floor practically every Monday morning, regaling us with his weekend's exploits. At first we were supportive, offering tips, congratulations for good finishes, and so on. But as the tales grew taller each week and the stories longer, we eventually just...well...stopped coming in on Monday mornings.
We realized that, like a poor puppy sometimes needs to be saved from chasing its tail, we needed to rescue Neuer from, um, chasing his tail. Sport Rider would take him under its collective wing, build a racebike for him and coach him up to speed. The final goal, a sort of coming-out party or prom night, if you will, would be Neuer racing a bike we built in the AMA's Formula Xtreme race at California Speedway, his first-ever AMA race. This is Part 1 of that story, covering the bike--in fact, our 2004 Suzuki GSX-R600 test unit--itself. Next issue, Neuer will tell his side of the story.
We decided to go the Formula Xtreme route for several reasons. With the recent downsizing of FX bikes from 1000cc to 600cc, it would be a chance for us to explore what a 600 is capable of with more than the usual Supersport modifications. As well, throwing Neuer into the Supersport or Superstock class would be like putting that lost puppy in a cage of pit bulls; for now, the Formula Xtreme class is the least--shall we say--frantic of the AMA classes.
Picking a starting point was somewhat a matter of availability; with most of the 600s new for '05 and our '04 GSX-R still sitting innocently in the shop, we pounced on the Suzuki. That way, rather than wait for a brand-new bike and even longer for parts to trickle in for the '05 models, we could start immediately. That settled, we began collecting goodies for the little GSX-R.
We'll admit our FX bike is not a full-blown factory-replica mini-superbike, but rather something a club racer could build given a decent budget and resources. You won't see a works hlins Superbike fork, $1800 one-piece billet Brembo brake calipers or hand-grenade horsepower readings on the dyno. We used reworked stock parts where possible, a conservative engine spec and a careful mix of aftermarket goodies to get the most bang (and the least headaches) for the buck. And besides, it's unlikely that the burgeoning AMA racer (that would be Neuer) could take advantage of some of the more esoteric parts available.
Suspension is traditionally the one setup aspect that takes the longest to dial in, so we addressed the GSX-R's boingers right away. We already had a rear suspension link ($399) from Ammar Bazzaz's BPD (Bazzaz Performance Design, see sidebar), which bolted right on and offers a flatter--and more racing-appropriate--progression curve than the stock linkage. We complemented that with an hlins shock ($1213) with full adjustability: remote spring preload, ride height, rebound damping and both high- and low-speed compression damping. Bazzaz opened up the brand-new hlins and tweaked the internals to better match the linkage, a modification he says is not strictly necessary. While we were on the phone with our friendly Parts Unlimited hlins representative, we ordered up an hlins steering damper ($455), which mounts in the standard position in front of the fork, safe from crash damage.
Inside the fork tubes, we replaced the stock valving with K-Tech compression and rebound valves ($399) from BPD, slid in a set of stiffer K-Tech fork springs ($101) and filled each tube with Maxima fork fluid. The K-Tech setup also replaces the stock compression adjusters at the bottom of each fork leg with "external flow control" valves ($120), which offer a greater range of adjustability. BPD offers an installation service for the fork internals ($200), but it was a fairly straightforward job we managed ourselves with the right tools.
Attack Performance provided a set of its beautiful triple clamps ($779), which are machined from billet aluminum and offer adjustable offset through the use of eccentric inserts. Installation required pressing the steering stem out of the stock bottom clamp (hint: You need a press to do this), as well as scrounging a fork clamp for the steering damper, as the stock unit mounts to the bottom clamp. It all went together painlessly, and we were able to change trail in less than a half-hour; no doubt professionals could do it in minutes with the slick Attack setup.
Next we turned to the Suzuki's front brakes. Formula Xtreme rules allow the replacement of the entire brake system, including discs and calipers, and originally we wanted to go with a complete Brembo setup. Turns out the only Brembo caliper available to fit the standard Suzuki caliper-mount spacing is the big-bucks machined GP-spec caliper. The cheaper cast units were on the horizon and may be available now, but we decided to stick with the stock calipers. We did have some brake troubles on our stock test bike and had heard reports from several racers about the new-generation GSX-R's brakes fading on the track. Some of that fading can be traced to the aluminum (instead of steel) pistons in the calipers, which, although lighter, transmit more heat to the calipers and brake fluid.
Our first brake-setup iteration consisted of swapping the stock rotors for a set of Brake Tech's iron Axis Design rotors ($330 each) and matching Ferodo pads. The Axis rotors' innovative design places the buttons that attach the disc to the carrier in a non-load-bearing position, which allows the rotors to be lighter and improves their thermal transfer capabilities. The discs are also cryogenically treated, a process that transforms the molecular structure by cooling the parts down to -300 degrees Fahrenheit. According to Brake Tech, this relieves stress and gives the discs a memory shape they return to after heat cycling. Additionally, the discs are made from ductile iron rather than the traditional gray iron, which allows the use of either sintered or organic pads. (Sintered pads can cause stress cracking in gray iron, and organic pads are usually required.) We used Ferodo's Sintergrip XR racing pads ($60 per caliper) as recommended and provided by Brake Tech.
HEL USA sent a set of its stainless steel brake lines ($164), which feature titanium fittings for light weight without the corrosion problems of aluminum fittings, and we used Maxima's DOT 3/550 brake fluid. We still had some fade problems with this setup, and while we couldn't pinpoint the exact cause, it turns out the stock radial-pump master cylinder is partially to blame. We replaced it with a Brembo forged aluminum unit ($360) from Brake Tech, and that eliminated almost all our fade problems.
Out back, we used another HEL brake line ($82), a Brake Tech rear floater disc ($180) that utilizes stainless steel bobbins on the mounting bolts to significantly reduce drag and a set of Ferodo organic pads ($34).
Once we had the suspension and brakes squared away, we concentrated on race prep and lightening the GSX-R. Attack Performance anted up with a set of its adjustable rearsets ($436) that are more art than motorcycle parts. Twelve positions of adjustment are available for the footpeg, and the shifter can be adjusted for leverage ratio. The pedals mount using ball bearings, resulting in smooth, precise action with no slop or wear, and the pegs themselves provide much more grip than stock. Likewise, Attack's 50mm clip-ons ($225) are beautifully made and bolted right up. Their design features replaceable tubes, the clamp is hinged and the clip-on can be removed without unbolting the top triple clamp or removing the fork leg; both features are handy in the event of a crash.
A phone call to Lockhart Phillips, which incidentally sponsors the Formula Xtreme class, netted a variety of necessities: Vortex heavy-duty case covers ($170 for the left, large cover and $70 for the starter side) are machined from billet aluminum and protect the engine in case of a tip-over. Proimpact's polyethylene frame sliders ($50) do the same for the frame and bodywork. Both the case covers and frame sliders mounted up with no trouble, and luckily we didn't have to test their crashworthiness. LP's own V2 Speedscreen ($70) sits a bit taller than stock, providing more wind protection and a clear view out the front.
Gearing necessities were taken care of by Sprocket Center, which supplied a selection of black-anodized RRP rear sprockets for both the stock and Marvic rear wheels, an RK GXW520 X-ring chain and RRP front sprockets made from case-hardened steel and drilled for lightness. A 520 conversion kit from Sprocket Center with the RK X-ring chain and two RRP sprockets retails for $180.
Instead of doing the engine work ourselves and then having a professional fix our mistakes afterward we went the direct route and shipped the motor off to Grant Matsushima's MPT Racing (see sidebar) for an overhaul and appropriate horsepower massage. Figuring 120 ponies would be in the ballpark for a reliable output, we asked Matsushima to perform a basic supersport prep, along with whatever tricks he had up his sleeve that were within the fairly liberal rules and didn't sacrifice reliability. He delivered, with a 118-horsepower mill that didn't miss a beat over nine days of track riding and racing. Matsushima reported that our 4000-mile test bike "didn't have any weird wear marks, but a lot of the components got replaced because I wanted it to be a fresh motor. They didn't get replaced because they were worn, they got replaced because it's a motor I'm building, and it's a motor that's going to be raced." On top of the freshening-up, Matsushima added a valve job and some mild porting, milled the head and slipped in "some short-duration Yosh cams left over from a couple of projects ago."
Exhaust duties are handled by a LeoVince full system ($1358), which is specially designed for Formula Xtreme-spec racebikes with a thin-wall stainless-steel header, titanium collector and a full titanium canister with a larger inner diameter. On the opposite end of the fuel/air combination, we used VP's Ultimate 4 racing fuel ($18/gallon), which provides power levels close to the company's MR9 rocket fuel but at a fraction of the cost. And to keep it all running smoothly and for that last bit of horsepower we filled the crankcase with Maxima's Maxum4 Ultra 0W-10 synthetic oil ($13/liter) that we know is good for a couple of horsepower.
Putting that power to the ground is a set of Marvic cast magnesium wheels from Yoyodyne and Dunlop 16.5-inch slicks. The Marvics alone cut several pounds from the GSX-R, and the rear wheel has a reasonably durable cush drive for which RRP makes sprockets to fit. Both wheels were direct replacements for the stockers, with the rear wheel's spacers captive to make wheel swaps much easier. We used medium-compound Dunlops for most of the project, in 125/80 KR106 and 195/75 KR108 sizes and constructions. According to Dunlop's Jim Allen, serious Formula Xtreme racers use this 16.5-inch setup, but a case can be made for swapping the stock 5.5-inch-wide rear wheel for a 6.0-inch hoop and using 17-inch slicks. Development in 17-inch slicks is progressing due to their use in the AMA's Superstock class. In any event, grip was never a problem for our bike.
European Motorcycle Accessories provided a Translogic Quickshifter ($615), which took some time to install. Almost all the connections--including the interrupts for the fuel injectors--required cutting stock wires and splicing in spade connectors. Even though we soldered and taped each spade connector, the setup was still a constant source of worry; we'd much prefer a unit that simply plugs into the stock harness or injector connectors. The Quickshifter itself worked fine, requiring almost no setup or adjustment, and it provided quick, crisp full-throttle upshifts. A programmable shift light is also available and can be wired in, as can a dashboard with a gear indicator, tach and lap timer.
The entire package is wrapped in a set of Hotbodies Racing fiberglass bodywork ($650). The flexible bodywork came primered, but we had to install the hardware and fix a few blemishes in the finish before having it painted. The fairing and seat mounted up easily enough and proved quite durable over the course of the project. Airtrix applied the incredible yellow-and-black paint scheme, and Imagine It graphics, our usual supplier for quality custom stickers, made the Sport Rider vinyl-cuts.
With no Ultimate 4 in the tank but all the data-acquisition equipment in place, the Suzuki weighs in at 367 pounds, 35 pounds less than stock but slightly porky for the 350-pound minimum weight limit for the class. Removing the Drack data-acquisition box (and its related sensors) and ditching the stock starting system, a modification Matsushima recommends, would most likely put the GSX-R as close to the minimum weight as we'd want to tread. For the complete tale of Neuer's first-ever AMA race and to find out how our bike fared in the Formula Xtreme race at California Speedway, check out Part 2 of the story in our next issue.
Matsushima Performance and Tuning
When Danny Eslick finished fourth in this year's Daytona 200, we knew we had made a wise decision to ship our engine off to Grant Matsushima's shop. In addition to performance engine work for street riders and racers, Matsushima runs MPT Racing, a Suzuki-supported Formula Xtreme and Supersport team with riders Eslick and Jeremiah Johnson.
Matsushima has a colorful past with a who's who of racers and teams. In 1998 he worked with Carry Andrew and Hypercycle on Nicky Hayden's Supersport bikes, and following that he went to Yoshimura, wrenching for Jason Pridmore for two years. In '01 Matsushima was Roger Lee Hayden's lead mechanic and built Supersport engines for the Bruce Transportation Group; the next year he worked with Ben Spies and Pridmore again on the Attack Performance team. A desire to provide privateers with better equipment led Matsushima to start his own business.
"I wanted to take all the experience I had and offer it to the public, because everybody builds stuff for the public, but they don't build everything they've got for the public. My motto for the longest time was, `Factory performance for the privateer'. I hooked up with Opie Caylor and we did the Team EMGO Taiwan thing in '03. We did the defunct Empire Racing last year. After that, after having to step into more of a crew chief-type role last year, I decided this year I wanted to do something on my own and actually have my own program. I approached Suzuki with it, and at first they seemed a little bit tentative because I don't have huge financial backing--I'm just an independent shop. Now I'm here and trying to make what I can out of what I've got." The association is off to a good start, as in addition to his fourth-place finish at Daytona, Eslick sits third in points (after three rounds) behind the factory Honda pairing of Jake Zemke and Miguel DuHamel.
"I hear rumors that [the Hondas] make in the 140 [horsepower] range," Matsushima says of the shrieking CBR600RRs of Zemke and DuHamel. "The best the Suzukis have ever seen--that I've heard from other people--is mid-30s. When you guys first approached me about this it was for more of a reliable, basic-spec motor. In hindsight, I probably should have built something that was a little less reliable and more in the way of FX. There's a bit of work that needs to be done; it's probably 50 percent of a full FX motor."
So what would it take to build our engine into a 130-odd horsepower weapon? Between $6000 and $8000 will get you the full Formula Xtreme build and close to what is in the team's bikes. "My full FX spec is hours upon hours of timing, compression ratio...I spend a lot of time even to this day working on the ideal spec." That specification includes removing the starter and its related gears, a porting job with major amounts of metal removal, titanium retainers, Carillo connecting rods, and even specially machined stock pistons, among other, unrevealed mods. "You're more worried about getting the thing to rev to 17,000 rpm," Matsushima says. Another trick he employs is his "water back-pumping kit," which redirects coolant flow into the head and out the cylinder block rather than the other way around. "I think it's what makes a lot of the difference between my motors and some other motors." True to his word, the kit is available to the public.
Bazzaz Performance Design
Ammar Bazzaz is no stranger to working with fast and good-handling Suzuki GSX-Rs. Before he opened BPD, he helped Mat Mladin to three of his AMA Superbike championships. Bazzaz rose to prominence as an expert on suspension and chassis setup when he designed a rear linkage for the Yoshimura GSX-R750 superbikes; a variation of that linkage is one of the products he now sells as part of BPD. Filling out the line of suspension parts he offers for sale are hlins and K-Tech components. While hlins is a familiar brand to sportbike riders, K-Tech may not be. Chief among the K-Tech parts BPD sells and services are complete 25mm cartridge internal kits and revalve kits for existing 20mm cartridges (which covers most sportbikes).
The British company also manufactures replacement compression and rebound damping adjusters. "90 percent of the K-tech piston kits come with a rebound piston holder, and that's what differentiates it from the other aftermarket products out there," Bazzaz points out." With that different rebound piston holder, there's also a different needle set that allows you more adjustment on the rebound circuit. But on the `04/'05 GSX-R600s, they have not developed that yet. Your kit uses the stock rebound piston kit."
Bazzaz is also well respected as a data acquisition and fuel management specialist, and has designed and developed his own replacement ECU for big-bore Suzukis that has an additional data-logging feature. He can often be seen at the races with his laptop connected to the innards of one factory bike or another, and this year, in addition to running BPD, Bazzaz has signed on to Jordan Motorsports as crew chief for the team's Superbike program.