Blackbird

BLACKBIRD

Half-naked, completely zero to 180 mph in 8 seconds

MARK HOYER

THE AURA IS ONE OF EVIL AND MENACE, BUT THE PURPOSE IS pure. And while there's nothing subtle about this 500-horse-power dragbike, subtlety is the only way to make the Nxt Level Racing Hayabusa work. How else could you possibly get a motorcycle with so much horsepower, no wheelie bar and a DOT tire down the dragstrip in 8 seconds or less at more than 180 mph?

Yes, making a turbo motorcycle produce a tremendous amount of horse power is relatively easy. Making a turbo motorcycle produce such horse power in a controllable manner is not. But control, says company owner Sebastian Domingo, is NLR's specialty. The trick lies in the turbo's waste gate, and the electro-pneumatic manipulation of it to tailor power delivery.

This is accomplished with the `Multi Stage Boost Controller," or MSBC. This electronic unit is mounted to the top triple-clamp, and manipulates the wastegate in six stages. These can be activated any way you like, but the typical setup is that the pulse that trips the air-shifter for each gear triggers the MSBC’s successive stages.

Electronics are the easy part, though. The really important item in the system is the dual-port wastegate. There are air fittings on both sides of a boost-control diaphragm connected to the wastegate. The port on the backside (vented to atmosphere on a normal system) is pressurized variably to control the amount of boost, essentially increasing or decreasing preload on the wastegate.

A dedicated pressure sensor feeds into the main unit, which in turn controls two solenoid valves to manage air pressure behind the diaphragm-one adds pressure, the other bleeds it off. You set the target boost for all six stages, and also control via nine different “ramp rates” how quickly the next level of boost is attained.

So, if, for instance, during runs the bike is wheelying on the shift from second to third, a slower ramp rate during the third stage can be used to combat the problem. Although the boost-management system can allow for as much as 60 psi, the bike’s EFI system is mapped only to 38 psi, and so far they’ve only managed to use less than 30 on the track. Off boost, the bike relies on the stock fuel and ignition maps, while a separate control unit and injection system compensates for on-boost running, using its own pressure sensor in the intake plenum. One of the more beautiful pieces of the turbo system, aside from the polished Triple K turbo itself, is the curved air-to-air intercooler mounted in front of the stock radiator.

As you can imagine, with so much boost feeding the engine, it gets its fair share of attention from Domingo, although the stock Hayabusa powerplant is pretty robust in the first place. JE makes lower-compression pistons to NLR’s specs, while new con-rods, Web cams and valve springs are fitted. The 1298cc powerplant’s bore and stroke remain stock. The clutch is uprated and features a multi-stage lockup mechanism, all the better to control the 320 foot-pounds (!) of torque.

The bike runs without the lower fairing to advertise NLR’s wares. One of those wares is actually the bike itself: NLR will set you up with a turnkey racebike for about $25,000, plus the cost of your donor Hayabusa. Domingo also sells the turbo kit separately for $10,700, but most customers want a turnkey machine.

The AMA/Prostar Streetbike Shootout class in which the black Busa races allows for a 68-inch wheelbase, and the NLR bike is near the limit at 67.25. The steel swingarm is built by McIntosh Machine and Fabrication, as is the shock linkage for the Öhlins shock. The fork is lowered internally and reworked to be topped out with the pilot in the saddle (helps keep the bike from wheelying). Marvic wheels are used front and rear, while lovely PFM discs and calipers replace the stock front brake system. These pieces are both pretty and effective in slowing the bike, but Domingo says they’re actually too light for his tastes! Half of the battle with this bike is keeping the front end down, and having a little bit more weight so low and forward really helps. So he epoxied lead shot to the underside of the front fender-the brakes were just too cool to remove. The class also requires a working headand taillight, the former being a Mini Maglite flashlight fed by stepped-down voltage from the bike’s charging system, which rules dictate must be functional. All told, it’s a tidy and effective package.

Potential customers often ask Domingo if he’ll guarantee that the dragbike he might build for them is capable of an 8-second quarter-mile. His short answer is, “Hell, no!” But that’s simply because he knows how important the rider is to getting good times. The NLR Hayabusa accomplishes its record-setting quarter-miles in the capable hands of Larry Laye. A former full-time motocross racer, he started outlaw street racing while still in high school in Southern California, but finally went legit when his wife became pregnant and he thought it more prudent to race on a track-on 450-horsepower, 6.80-second, 200-mph Funnybikes! After several successful years racing professionally, he met Domingo at an early SoCal test session for the black Busa. Domingo asked if Laye wanted to have a go on the bike, and one run was all either man needed. Domingo decided right then, after having originally built the bike for himself, that putting a talented professional in the seat would maximize his chances of success.

He was right. The bike made its racing debut in April of last year with Laye at the controls, and things went well. “We set the West Coast record of 8.43 seconds at 176 mph, breaking the established record of 8.77/163, at Firebird Raceway in Arizona, our first time out. And every time the bike has been out, we’ve broken our own record, which is good because that means we’re going forward.”

The black Busa now holds the AMA/Prostar/NMRA West Coast ET and speed records of 8.07 seconds and 180.21 mph, set during separate runs. Adds Domingo, “It’s the fastest any Hayabusa has ever gone in the quarter-mile on a street tire and with no wheelie bar.”

Laye prefers racing the Hayabusa over his former Funnybike because of how active the rider must be on a bike with so much power and no wheelie bar. “On the Funnybike, you pretty much two-stepped the clutch and hung on,” he says. “With this thing, you’ve really got to have a lot of control and work the throttle and clutch.”

The latest record attempt was at the end of 2001, running in Gainesville, Florida, at the AMA/Prostar U.S Drag Racing Championship final event. Domingo and Laye were excited to be headed to a sea-level strip that had a good surface, and hoped to set the national record in the class. The competition was stiff on the East Coast, the accepted center of the dragracing universe.

They qualified fifth with an 8.008-second run at 184.61 mph, the second-fastest terminal speed in qualifying. Unfortunately, they were eliminated in the second round of finals when Domingo says a sparkplug failed. And that, as they say, is racing.

He says they’ll be back. No doubt he’ll spend his time working on the subtleties of fully exploiting 500 horsepower.