When Suzuki announced that they were going to commence production of the sensational B-King concept bike that was displayed at the 2001 Tokyo Motor Show, the public was anticipating the first forced-induction production motorcycle (the concept B-King featured a supercharger) since the turbo bikes of the late 80s. In 2008 when the concept finally became a reality, the market was handed a naked bike based on the Hayabusa engine, but the boost was gone. Instead, we got a naturally-aspirated 160-horsepower streetbike with styling that was not exactly eye candy.
When Barry Henson at Velocity Racing saw the production B-King, he looked at it as an opportunity to build an actual boosted version. Velocity is the leading supplier of turbo systems in the USA and also runs the most successful AMA Dragbike and MIROCK racing program today. Velocity-equipped bikes have won 13 championships stateside and three more in the UK. These turbocharged Hayabusa "streetbikes" have turned quarter-mile times as low as 7.18 seconds and 205 mph with rider Mike Slowe.
Before starting the project, Velocity sat down and mapped out its goals: to build a clean, streetable package without overdoing it. This meant no gaudy paint, and a resemblance to a bike that Suzuki would have built if they weren't constrained by production cost and marketing concerns.
Because Velocity has produced and sold over 1000 turbo kits for the Hayabusa, it was not a huge leap to develop a kit for the B-King. With the intentions of making a 100 percent streetable system, they chose a Garrett GT-25 turbo. With six psi as the target boost level, the oil-cooled GT-25 had more than enough volumetric capacity, plus the slightly smaller housing made packaging it on the bike easier as well. In keeping with the OEM theme, the turbo compressor housing was Jet Hot(r) coated black while the turbine housing was treated to a sterling silver finish to keep corrosion in check.
Instead of the turbo exhaust...
Instead of the turbo exhaust just feeding into a dump pipe per the standard kit, Velocity decided to fabricate a custom exhaust that replicates the stock B-King twin underseat muffler setup.
For the B-King, Velocity had to develop a new plenum and up-pipe to transfer the pressurized air flow from the turbo up to the intake side of the engine. Unlike most sportbikes where the up-pipe is hidden under the farings, the B-King's naked styling makes the intake pipe partially visible. So these parts were similarly dressed up with a black powder coating to make sure they meet the visual inspection standards in play.
The standard B-King turbo kit retails for $3995 which includes a dump pipe. However, this one was upgraded to a full exhaust to replicate the styling of the stock B-King. The system consists of a hand-welded stainless steel header and midpipe. Then it finishes with a pair of Vance and Hines Indy Series canisters. The exhaust and aftermarket canisters add another $2000 to the total.
One of Velocity's own 6-inch-over...
One of Velocity's own 6-inch-over swingarms holds an 18 x 8.5-inch RC Comp Savage forged aluminum wheel shod with a 250/40R-18 Avon Cobra radial.
Even though the B-King comes with a 200-series rear tire, the decision to go even bigger meant a new wheel and swingarm. Since Velocity already produces their own line of swingarms, they simply fabricated a six-inch-over piece to handle a wider wheel and powder coated it black for another $1100. To fill up the swingarm, an 18 x 8.5-inch RC Comp wheel was wrapped with a 250-series Avon tire. In the front a RC Comp wheel was mated to the stock front tire. The RC wheels are another $2200. An EK-ZVX2-530 chain was then added to handle the extra power.
The bike comes from the factory making about 160 horsepower, but the Velocity boost treatment nets the Suzuki 205 horsepower at the rear wheel even with the big tire kit, which robs about 20-25 horsepower due to the added weight and rolling friction. Thus, if you boost your B-King without the big tire kit, you can expect more like 225 horsepower on the ground.
Henson jettisoned the ugly...
Henson jettisoned the ugly stock taillight/license plate hanger and fabricated a custom setup using a GSX-R1000 tailight for a much cleaner look to the B-King's rear end.
In order to give the bike the proper stance, Henson lowered the front two inches by internally modifying the forks. This prevented having to drop the forks in the triple clamps and result in a hacked-up look on a trick custom bike. To get the rear riding at the right height, a set of one off lowering links were fitted which dropped it two inches as well. The last part of the lowering process was shortening and re-welding the kickstand so it too maintained a stock appearance.
As supplied by Suzuki, there are several parts that are bright aluminum or plastic, so Velocity powder-coated or replaced them as required. The stock plastic chain guard was ditched and replaced with a custom aluminum unit that features an integral license plate mount and LED tag light. The stock foot peg mounts were also powder coated black.
One of the worst looking parts of the stocker is the rear fender/license plate mount. Hanging down well below the under tail exhaust, it makes a styling statement that most people hate. In order to clean this up, Velocity completely removed the mud flap, inner fender, license plate mount and tail light. In its place is a new setup borrowed from a Suzuki GSXR-1000. The result is a far better looking arrangement that no longer looks like a mud flap from a delivery truck.
The typical six psi turbo kit doesn't require a lot of internal modifications, but since this was built to be Barry's personal bike, he opted for a few upgrades here as well. For starters, he installed a set of high-tensile APE studs and nuts to make sure the head was held tight enough to survive repeated boosted runs. He also fitted an APE billet cam chain tensioner. The rest of the engine, however, is stock, including the rods, clutch, pistons, etc.

With the extended swingarm,...

With the extended swingarm, the stock plastic chainguard was ditched in favor of a custom-built aluminum piece with integral license plate mount on the end. An EK ZVX2-530 chain delivers the power to the rear wheel. Note the custom rear suspension dogbone links to lower the rear ride height.

Henson lowered the front end...

Henson lowered the front end two inches by modifying the fork internals, avoiding the problems associated with raising the fork tubes excessively. Everything else on the front end, save for the RC Comp wheel, is stock.

The custom-fabricated exhaust...

The custom-fabricated exhaust shows some exquisite welding on every section of the piping. Heat shield foil keeps the underseat plastics and electrical components from being melted by the exhaust heat.
When we arrived at the Velocity Racing shop just outside Lexington, Kentucky, Henson wheeled out the bike and as he started up the engine, I noticed it only had four miles showing on the odometer. I asked if it was completely set up and broken in and Henson assured me it was. In fact Henson said that on this bike he simply installed the kit, downloaded a map into the Power Commander, and then made one dyno pass. He claimed it was so well-sorted right out of the box that no other work was necessary. I have ridden more than a few aftermarket turbo kits and in my experience if their fuel and boost maps are not tuned to almost near perfection, there nearly always will be a host of drivability issues. It was time to see if Henson's reputation for quality construction would continue untarnished.
The first thing I noted after thumbing the starter was how it sounded. The Vance and Hines open exhaust canisters result in a real nasty turbo bark, especially for a street bike. Henson was quick to add that if the owner prefers, he has some quieter replacement mufflers. But with such a Mad Max-style bike, the sound fit the character perfectly.
The Velocity turbo B-King showed no signs of being cold-blooded, and easily powered away with no stumbles or coughing. Of course, I could only wait a few miles before unleashing it, as I couldn't wait to feel the turbo on a big naked bike of this size. At highway speeds the turbo spools up quickly and very noticeably no matter what rpm or throttle position you're at. There is never a lag or shudder from the big engine. I even lugged it down as far as 1900 rpms in top gear and after whacking the throttle open it simply spooled up and began to catapult me forward with alarming ferocity.
One major difference in riding a turbocharged naked bike versus a Hayabusa is that there is nowhere to hide from the wind. Even on a 500-horsepower Busa the wind blast is so well managed that it can be pretty deceptive, but on the B-King you know you're going fast without looking at the speedo or tach.
After a few top gear blasts I decided to drop it back a few gears and see what it felt like in the lower gears. After slowing and dropping it into 2nd gear, I pegged the throttle and watched the tach to make sure I didn't miss my shift point. As the tach neared 9000 rpm, I noticed the needle bouncing around as if the clutch was slipping, but after looking in the mirrors I figured out what was really happening. The white smoke and blackie on the road signified that although the clutch was locked up solid, the Avon tire was struggling to manage the 200 horsepower that was being fed to it. Even at highway speeds, the boosted B-King could spin the rear tire at will under heavy throttle and boost.
The heart of the Velocity...
The heart of the Velocity B-King turbo is a Garrett GT-25 oil-cooled turbocharger. With a conservative six psi maximum boost setup on the kit, the GT-25 has more than enough volumetric capacity while allowing fairly quick spooling, and its small size permits easier packaging.
Anything beyond third gear and traction was less of a worry and getting out of the wind was the only concern. This was absolutely the best aftermarket turbo bike I have ever ridden in terms of its streetbike manners. I tried to make it misbehave or find a fault but there simply weren't any to be found. I still can't believe that it only had four miles of setup/break-in and was sorted out this well.
The Garrett GT-25 turbo is perfectly suited to this package; it spools fast and is still large enough to deliver impressive horsepower. For this stage one kit, Velocity relies on the stock injectors and feeds them with a rising rate fuel regulator (FMU) to keep the air fuel ratio set.
The net weight of the bike is about the same after installing the kit. Though the turbo and related plumbing weigh about 43 pounds, the removal of the factory exhaust, cat and inline exhaust valve brings you back to a net gain of zero. Plus the mass of the turbo system is below the centerline of the bike so the only thing you will notice is the added power, as opposed to any weight gain.
With the larger 250 rear tire, longer swingarm, and lowered suspension I was worried about the Velocity B-King not really being suited for true street riding, but those fears also faded as I racked up more miles. While it is intended to be a hard charging boulevard pounding hooligan bike, it can still be ridden every day. I spent a fair amount of time on some curvy Kentucky back roads and even in that environment it performed decently. If you keep in mind what the bike was built to be, it delivers exactly what it promises.
We asked Henson about the reliability of this setup and he assured us that with the low boost, tens of thousands of miles with little more than normal oil changes would be the norm. One thing for certain is that this B-King is a true Kentucky thoroughbred and after spending some time in the seat it is no wonder that the Velocity Racing shop has dominated the racing scene as long as they have.