Some people just can't get enough of a good thing, and Richard Sims--not that we're complaining, mind you--is one of those people. You see, for Sims that good thing is horsepower, and we love sampling the results of his addiction. We've seen supercharged, nitro-burning, big-bore GSX-Rs from Sims' Los Molinos, California, shop in the past, and this nitrous-snorting Kawasaki ZX-9R is the latest creation to fall into our greedy paws. The only external clue to the Kawi's intentions is an extended swingarm. But under the Airtech bodywork and stretched seat lie go-fast goodies aimed at giving this green meanie some serious top-speed and quarter-mile potential. How does a Muzzys motor with 160 ponies--and nitrous oxide good for up to 80 more--sound to start? But the beauty of it all is that the ZX-9R serves duty as daily transportation for Sims a few times a week, and we're sure its Q-ship nature has left a few unwary squids with long faces.
We tried the Sims ZX-9R at Los Angeles County Raceway, but teething problems with the shifter and nitrous setup made for unspectacular times. Wheelspin on the track was a definite problem, even without the laughing gas. Switching from the street-compound Avon to a Mickey Thompson Shootout tire quickly solved that.
Sims started with a box stock 1998 Kawasaki ZX-9R, and even logged 300 break-in miles before he started tinkering. The bike was stripped down to its last nut and bolt, and then Sims began what he estimates to be 1500 hours of labor as the bike took shape over the course of a year.
Lifting the seat off reveals where Sims spent the bulk of his time; electrical wiring, braided stainless steel hose, controllers, solenoids, bottles...all neatly packaged and yet easy to access. Sims' handiwork--artfully machined and welded bits of titanium and sculpted and purple-anodized aluminum brackets--is spotted easily. It's almost painful to consider the effort and attention to detail involved. Core to the bike's performance is its progressive nitrous oxide system, which works with a shift counter to soften the hit during quarter-mile runs. The system is automatically activated when the bike is shifted into third gear--second if the rider is ballsy--and the Schnitz controller gradually ramps up the amount of nitrous injected while the Dyna ignition module backs off the timing a tad. Use the horn button to shift, and it's all quite simple, really.
While Sims was busy mounting hardware to the chassis, the 9's engine was getting the Muzzys treatment. Muzzys 76mm pistons--mounted to polished and balanced connecting rods--replace the stockers and bump displacement to 924cc and compression to 13.5:1. Up top, a five-angle valve job and porting by Rob Muzzy himself speeds up the gas flow, and camshafts specifically for nitrous oxide applications were installed. Valve springs and adjustable cam sprockets are Muzzys parts, and gases exit the party through a Muzzys titanium pipe.
With the engine returned and mounted in the frame, Sims turned his attention to the details: power gets to the ground via Vortex sprockets, a super-long RK chain and Avon street-compound Azaro tires. Stopping duty up front is taken care of with 13-inch cast iron rotors and Nissin six-pot calipers, both from Ferodo Brake Tech, plumbed with Goodridge stainless steel hose. And a Corbin seat makes sure our man Kunitsugu stays in place when he twists the throttle.
We had a chance to try the bike at the dragstrip shortly after its completion, but before the nitrous and shifter systems were fully sorted and on-line. While the ZX-9R showed lots of potential in just a few passes, a full riding impression will have to wait.
Sims Engineering
8295 Marek Rd.
Los Molinos, CA 96055
(530) 384-1739 phone/fax
Busy office: Race Tech-modified forks slip into stock triple clamps, and a Hyperpro steering damper calms things down. Two Brothers clip-ons are loaded with street equipment--the horn button activating the power shifter--along with the nitrous-override button on the left. Glycerin-filled gauges on the right keep tabs on fuel pressures. A Lockhart Phillips windscreen tops things off, and there's a shift light just to the left of the brake reservoir. | 
This progressive nitrous controller from Schnitz Motorsports (219/728-9457) works with the Dyna shift counter to provide different amounts of nitrous oxide depending on gear position, as well as easing the hit. The injection pulses can be modified independently for duration, frequency, mixture and timing over a 12-second span. The cable-end hanging in free space is the seat release. Geesh, Richard, we'd have expected some kind of fancy knurled, anodized, billet aluminum piece...is that the best you can do? |
A titanium sub-subframe (fabricated by Sims) extends the tailsection and provides a mount for the hinged bottle holder and other electrical bits. The small bottle in the foreground is a smaller nitrous bottle for the power shifter. Sims originally had a Y in the main line and used the large carbon-fiber bottle for both, but encountered trouble when pressure was low. | 
The gizmo on the end of the 41mm Keihin smoothbore rack is a throttle position sensor, with a small micro switch. Hitting third gear (or second, if you feel lucky) at full honk starts the nitrous. Backing off the throttle after, aborts the feed. A 924cc Muzzy-built motor (with the man himself porting the head) is good for 160 horsepower, and up to 80 more on the bottle. |
A Dyna 2000 (626/963-1669) ignition replaces the stock black box, coils and trigger, and retards the timing when the engine is running nitrous. The wiring diagram for the whole system--ignition, nitrous, shift counter and power shifter--is a nightmare. Scott Valentine and Karl Steinwachs of Dynatek were instrumental in making the various systems work together. | 
Vortex Racing supplied the trick machined rearsets, as well as the sprockets. A super-long RK chain puts the power to the ground. The Orient Express (800/645-6521) power shifter runs off nitrous (does that make it a nitrous shifter?) which provides more shifts per fill-up; the Dyna shift controller provides the signal and kills the ignition for a preset duration. |
Miles of Goodridge stainless steel tubing starts here at the Holley Blue fuel pump, and end at an individual stainless steel nozzle for each cylinder. |  |
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Below: Wow! When the nitrous hits, extra fuel is required to match. Each cylinder's nozzle has a Y fitting with nitrous and gasoline feed. A bypass regulator ensures a constant flow of cool fuel to the float bowls at 4 psi, with fuel feed to the nitrous nozzles separately fed at 6 to 7 psi. This adds up to a lot of plumbing. The entire system was made by Nitrous Oxide Systems (270/782-2900) to Sims' specifications. |
The stock swingarm was relieved of its rear 12 inches. Sims machined adapter plates that slip inside the remainder of the stock extruded sections by approximately two inches and welded them in position. The adapter plates provide two mounting options for the rear axle; one in a near-stock position, and the second 53/4 inches further back. The frame, swingarm and triple clamps were all sent to The Frame Man (916/927-9712) for blueprinting and straightening. A Race Tech modified shock and handmade, shortened link arms complete the rear suspension. The stock rear disc is lightened, and the caliper mounts to a handmade bracket and adjustable stay arm. Titanium axle and aluminum chain guard were fabricated by Sims, as were the pipe hanger, fuel pump guard and anything else that's purple anodized. Hey Richard, what's your favorite color? | |