Triumph Rocket III And Harley-Davidson V-Rod - Boost Brothers

Turbo Connection turns a Triumph Rocket III and a Harley-Davidson V-Rod into true boulevard badasses

Turbo Connection's Harley-Davidson V-Rod will evoke similar, long-lasting memories, but for slightly different reasons.

Ever wonder how many Harley-Davidsons there are at Daytona Beach Bike Week? Tens of thousands, probably. Hundreds of thousands, according to some. So, rumbling along Speedway Boulevard on what is perhaps the fastest, most powerful street-legal Harley in all of Florida feels pretty good.

Especially when I jack the throttle open on a lightly trafficked back road and the Harley doesn't hesitate. Its relaxed exhaust note becomes a snarl, and the bike leaps forward with near shoulder-splitting force, its acceleration sending me storming past other vehicles and onto the open road, eyes watering behind my shades and a big, nasty grin on my face.

When I back off to shift there's a high-pitched sound from somewhere near my right boot, but I don't need that to tell me this bike is special--its ferocity does so well enough. Within seconds I'm approaching an indicated 140 mph in top gear, the V-Rod still pulling hard until another car looms up ahead to slow me down.

The standard V-Rod is quick thanks to its 1130cc, liquid-cooled, dohc eight-valve engine. But Turbo Connection's version is far quicker. On the lower of its two boost settings the V-Rod puts 156 horsepower through its back tire--nearly as much as the standard V-Rod's 107-horse output on the same dyno.

Running high-octane fuel gives even more performance at the flick of a switch. Selecting the high-boost setting using the switch located to the left of the fuel tank bumps maximum boost from 7 to 9 psi and increases peak output to 170 bhp at 9000 rpm. Yes, you read that right--one hundred seventy horsepower from a street-legal and very rideable Harley-Davidson.

Turbocharging can do that for an engine, as Olson is fond of demonstrating. Although he's concentrated on Triumphs since starting Turbo Connection in '92, he couldn't resist doing a V-Rod, which turned out very different from his Rocket III project. That bike is a sleeper, its turbo tucked away unobtrusively beneath the huge engine. The V-Rod's tightly packaged, lower-slung lump left no room for a similar approach.

Besides, the Harley rider's unofficial motto is, "If you've got it, flaunt it." So hanging proudly off the V-Rod engine's right side, breathing through a big filter and plumbed in with chrome-covered tubing is another iBoost turbocharger. Several years ago, Aerocharger produced its own very effective turbo kit for Harley's air-cooled V-twins, despite conventional wisdom that says turbocharging works best for multicylinder engines because twins, with their relatively infrequent and irregular power pulses, are more susceptible to turbo lag.

Lag occurs because a turbocharger has to spin very fast (100,000-rpm-plus) to deliver useful boost. At low-rpm throttle openings a conventional turbo spins slowly because most of the exhaust gas is diverted past it by the wastegate. So when the throttle is opened there's a delay before full operating speed is reached. The iBoost turbo's variable vanes, however, restrict the exhaust inlet when the throttle is partly open, so some boost is generated whenever the motor's running, and the time taken to reach full boost is much shorter.

"Lag? There is no lag," says a grinning Olson, and he's basically right. The kit was reasonably easy to develop, he says. As well as the turbo unit, it includes a plug-in computer to modify the injection system, a stainless steel exhaust with a SuperTrapp muffler and a neat combined intercooler and airbox that sits under the dummy tank."The V-Rod has relatively high compression [11.3:1], so you need a cool charge going into the engine," Olson says. "That's why the intercooler's necessary on this bike and not on the Rocket III. My aim is to make kits easy to fit and run reliably without needing any major work. The V-Rod is a very strong motor that's well suited to turbocharging." Another advantage of the iBoost's design is that the turbo is lubricated by its own self-contained system of specially formulated oil instead of relying on engine oil as a conventional turbo does.

Stiffer clutch springs mean a little extra effort is required at the lever, but in other respects the turbo V-Rod is as easy to ride as a stocker. And any inconvenience is quickly forgiven every time I wind back the throttle, which sends the V-Rod leaping forward like no other Harley I've ever ridden. Top speed is limited by gearing and neck strength rather than horsepower.

But it's the turbo 'Rod's extra midrange stomp that really impresses. The standard V-Rod engine is relatively peaky for a twin, with a torque curve that dips notably at 5000 rpm before rising toward its 72.4-pound-feet maximum at 7500 rpm. By contrast, the turbo-motor's curve peaks 2000 rpm earlier at no less than 121.6 pound-feet (108.8 pound-feet on the low boost setting), so the Turbo Connection bike is putting out 68 percent more torque at that point.

What that means out on the asphalt is that cracking open a standard V-Rod's throttle at about five grand results in not a whole lot of forward oomph, but doing so on this bike produces a reaction strong enough to bring the Daytona Beach tide in early. It also makes for effortless, instantaneous passing. And the V-Rod's robust chassis and strong brakes are quite capable of coping with the extra speed.

For such an outrageous performance mod, the turbo kit is surprisingly practical, too. And the Turbo Connection kit's price looks like an even better value when you consider more traditional, labor-intensive tuning alternatives. It's difficult to think of a simpler, more effective way to bolt serious horsepower onto a Harley--or of a more appealing method of ending up with one of the hardest-accelerating bikes in Daytona. MC

HOTBOX
Turbo Connection
2019 Eclipse Ave
Rapid City
SD  57703
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