Building a Nitrous-Injected Beast

Wild File: Streetfighter Perfection With a Gixxer’s Punch

Brian Hatano's nitrous-injected streetfighter build
This nitrous-boosted streetfighter started out as a 2003 Suzuki GSX-R1000 bought on Craigslist and built on the pages of Super Streetbike magazine (see Part 1 here)Brian Hatano

You were probably sporting a mullet under your helmet back when the first roached-out streetfighter started prowling the streets of England in the 1980s. 'Fighters, as we know, were all about keeping a crashed sportbike up and running by shedding bodywork too expensive to replace. Streetfighters have been popular ever since, with efforts from the pros and amateurs alike dotting the scene. Now we have custom bike builders dishing out some over-the-top fighting machines with unique influences. In the V-twin world, customs rolling out of Roland Sands Design are essentially streetfighters based on highly modified Buells and H-Ds, while Chris Redpath of MotoGP Werks has put his race-inspired, hand-built touch onto some exotic and high-dollar brawlers. Of course, the manufacturers themselves have tried doing streetfighters, but most of them are too tame or too polished to really have the vibe.

Hatano's Suzuki Streetfighter
A bargain Craigslist buy turned into a killer streetfighter with the right combination of aftermarket parts.Brian Hatano
Hatano's Suzuki
The crew at AIP Racing in Santa Clarita, CA handled the mods on this one. See part 2 of the Super Streetbike build HERE.Brian Hatano

Despite all the noise, streetfighters have survived both the mega-ticket items and manufacturer efforts. No better example exists than this GSX-R-based fighter built by All Industries Performance in Van Nuys, California. The shop is owned by Chris Jones and Clint Solomon, who clearly love all things old school and have found a way to instill their own retro-modernism into creations ranging from supercharged Harley-Davidsons and carbon fiber-themed Rocket IIIs to stretched, fat-tired sportbikes and custom streetfighters.

Motorcyclist Wild File
Digital Editor Brian Hatano's 2003 Suzuki streetfighter gets a boost in power from a Nitrous Express EFI Power Booster kit with a #20 jet.Brian Hatano

AIP went clean and retro when it came to this Gixxer. In fact, this bike started life as staff-instigated Project 'Fighter in Super Streetbike, a sister magazine to Motorcyclist under our old owners. The idea and execution of this project are simply too good to let a shuttered magazine keep it out of the limelight. So here we are.

The project is based on a street-scarred 2003 GSX-R1000, a local Craigslist score with more than 34,000 miles on the odometer. Rather than trying to work around a 10-year-old sportbike that had seen better days, the AIP crew took the Gixxer down to a bare frame so that every part of the bike could be inspected for damage and rebuilt from the ground up.

AIP fabricator Solomon repaired a minor crack in the frame (from a low-side drop) followed by a few subtle mods to clean up areas that would no longer be concealed by bodywork. Prior to paint and powdercoating, the frame, engine, subframe, and exhaust were mocked up to check fitment and see what kind of brackets and hardware would be needed for the new LeoVince exhaust, LSL rear brake reservoir, and Fight-Machines universal tail and belly pan. A used Hayabusa swingarm was pulled from the AIP take-off pile to replace the stock item. The extra inch gained in wheelbase is not just for keeping the front end down; it helps visually offset the squatty look of the shortened tail.

With the bike's tank and custom streetfighter body parts being prepped for paint, the crew at AIP used the downtime to check valve lash, compression, and leak-down before giving the engine a clean bill of health. This laid the groundwork for a simple, budget-friendly power increase: nitrous.

Hatano's Suzuki
Modifying the tail is what gives a streetfighter its aggressive profile. The Fight-Machines Evo tail is a universal-fit fiberglass piece that requires extensive subframe alterations to fit.Brian Hatano
Hatano's Suzuki Streetfighter
The Gixxer subframe was shortened by 11 inches, and the leading edge of the tail was shaped on the belt sander so it would match up to the contour of the fuel tank.Brian Hatano
Hatano's Suzuki Streetfighter
The engine and all wiring are removed as AIP’s Blas Gomez starts modifications on the frame. Going naked requires several tabs and air intake flanges to be removed.Brian Hatano

That upgrade comes from a Nitrous Express EFI Power Booster kit, which is known as a "dry shot" system. (In simple terms, a dry-shot setup injects oxygen-rich nitrous oxide into the intake stream where it mingles with an enrichened fuel/air mixture to produce more power. A "wet-shot" system pours in both nitrous and extra fuel. Nitrous itself doesn't add power; the ability to give the engine more oxygen to consume with extra fuel does.) The EFI Power Booster is a dry system that will work with any factory fuel-injected sportbike with ram-air induction.

Chris Jones ran Project 'Fighter up on the AIP Racing dyno to get baseline power numbers and fuel-curve data. Although the bike was equipped with a Power Commander III, there was no map installed by the previous owner. Jones remapped the bike with the new LeoVince GP Pro pipe and K&N; air filter before making the first nitrous-assisted run and came up with a best baseline power number of 131 hp and very linear air/fuel ratios (AFR) in the 13.8:1 to 13.9:1 range. Mike Golightly of Nitrous Express attached his 10-pound nitrous tank for testing purposes, and Jones made a series of nitrous-assisted pulls starting with a #16 jet. (The number refers to the jet's inner diameter, in this case 0.016 inch.) That setup yielded a best run of 137 hp. Stepping up to a #18 netted 141 horses with adjusted AFRs still in a safe pattern. Our final run with the #20 jet and Jones' custom map produced 153 hp, a steamy 23 up on the baseline.

Hatano's Suzuki Streetfighter
Project ’Fighter is mocked up and then disassembled once more for final paint.Brian Hatano
Hatano's Suzuki
Eugene Smith of B&E Customs in Chatsworth, CA applies three coats of urethane clear over the metallic blue and light gray base colors. The final step was a cut and buff after the paint was cured to give the 'Fighter its smooth, glossy finish.Brian Hatano

Nitrous is a bit of an old-school route to more power, true, a theme echoed elsewhere on Project 'Fighter. The final stamp of a true custom is, of course, the paintwork. To handle the final step of Project 'Fighter we called on B&E; Customs in Chatsworth, California, where metal expert Bob Dale and master painter Eugene Smith are turning out some of the area's finest rods, trucks, and bikes. B&E; stayed true to AIP's retro theme with a modern take on the early '80s Katana colorway, adding their own custom twist to the paint with a heavy flake in the metallic blue, accented by hand-brushed red pinstriping and Suzuki "S" logo.

Hatano's Suzuki Streetfighter
A Koso RX-1N gauge replaces the OE dash. LSL bars and billet components from Speigler USA bring the controls up to a streetfighter level.Brian Hatano

"S" for "superman"? An extra 23 hp on a bike whose center of gravity is much higher than Suzuki ever intended makes for some superhero moments. Without the juice, the 'fighter is entertaining enough. Punch the button and ride the gas for a thrill ride you never expect from a decade-old sportbike. Even better: As comfortable as the '03 GSX-R1000 was by sportbike standards, the new upright ergos makes riding beyond city limits more cruise than bruise. The Suzuki feels more like a ZRX of the same model year than a hunched-over superbike.

Hatano's Suzuki Streetfighter
A color-matched seat pad was fabbed by HT Moto using the fiberglass pan provided by tail manufacturer Fight-Machines.Brian Hatano

The only difficulty we had was keeping the front Metzeler in contact with the road thanks to some aggressively lower gearing and a higher center of gravity. Braking is improved over stock—with the addition of braided lines—but still not up to par with a new Brembo-equipped GSX-R. Handling is what you'd expect from 10-year-old technology, and like any naked bike, wind protection is nil. But what this bike delivers in abundance is 'fighter attitude with a wow factor that only a custom build can provide.

Hatano's Suzuki Streetfighter
A Hayabusa swingarm is mated to the 2003 GSX-R1000 frame, all powder-coated in a light Mercedes-Benz pearl gray to compliment the coarse metallic blue paint. Bike-builder Chris Jones of AIP Racing came up with the scheme inspired by the early Suzuki Katana. Chain is RK Excel, sprockets are from Supersprox. The color-matched blue-painted NX bottle and solenoid are installed under the tail. That’s where the fun comes from.Brian Hatano
Hatano's Suzuki Streetfighter
The custom spoked rear wheel features a Harley-Davidson hub offset to the left.Brian Hatano