The Albrex Rocket III Turbo

Big Gun Boost

Whether your bike weighs 700, 800 or 900 pounds is immaterial when you've got three cylinders and 2300 cc sitting in the engine bay. weight watchers becomes even less important when you can hit a turbocharger to energize that already-hefty displacement. At this point it might be more crucial to employ a two-handed iron grip, immovable shoulder sockets and a truly iron butt. It'll come in useful when a handful of throttle and a reinforced clutch send all that power to the gearbox and the jarring thrust flattens you into the single seat like a compressed Slinky.

Of course we're all well aware the stock Triumph Rocket III is already the largest-displacement production bike on the planet, and few riders would say that its stock output-140 hp at 5,750 rpm and 147 lb-ft of torque at 2,500 revs-makes for a wimpy ride.

We've heard rumors that Triumph's engineers actually toned down the force of the Rocket's three cylinders by backing off the injection mappings, though we'd bet most owners are more than happy with the stock performance numbers.

But for those who believe in excess there's Conrad Gruber. The 40-something Austrian has developed a following by specializing in helping bikers whose primary concern is bigger, better and faster. They come to him from all over the world, leaving their Ferraris and Lamborghinis at his workshop in the picturesque village of Wildschnau in the Austrian Alps. They return after a couple of months (depending on the complexity of the work) inevitably thrilled that their favorite toy now has at least 50 percent more power.

Gruber's Albrex shop is all about ful-filling the dreams of the young at heart, so naturally most of his customers also have one or more motorcycles in their garage. Many of them are musclebike devotees who went out and got a Rocket III when the new V-Max was nowhere in sight and the Suzuki B-King hadn't surfaced. And these are the guys who also want their Triumph's 240 rear tire to go up in smoke much more quickly-by adding some "real" power.

That's the backstory, anyway. And so it was that after a first ride on a Rocket III, one of Gruber's clients sent his British bike to beautiful Austria with a note reading, "Conrad, you've got to put a turbo on it to make sure that this bike gets some true power." The instructions were followed up with a nice budget allowance and six months of conversion time.

But it's not as simple as plugging in a kit from your local Pep Boys. A turbo conversion that can handle triple-digit Autobahn speeds without a problem requires plenty of professional engineering, much of it by hand. First, Gruber stripped the engine and examined the innards. Determining all was stout inside, he put it back together, painting the block black with a heatresistant enamel for a stealthily attractive look. The next step was to assemble a new manifold to feed the turbo with exhaust gases. Though he'd been down this path before, making the three manifold pipes equally long and as short as possible required a deft touch. Then he asked KKK to manufacture a special turbocharger for the 2.3L engine to quickly build up boost. It maxes out at 0.58 bar (8.4 psi), after which the pop-off valve vents excess with a honk.

According to Gruber the Rocket mill has a relatively low compression ratio of 8.7:1, which nicely complements a turbocharger. "The Rocket III motor seems to be made for this kind of power increase since it is massively built and has got lots of reserves inside."

Naturally just a turbo isn't enough, so in went two power-friendly intercoolers left and right on either side of the radiator. They're bulky, but Gruber is already planning a more attractive design. Because the triple cylinder mill seemed to have a stoutly engineered cooling system, the Albrex conversion didn't require modifications on the cooling circuits for water and oil.

The tuner also gave the bike an auxiliary ECU with a special mapping for the turbo engine. It is responsible for trimming the injection and ignition systems with painstakingly calibrated mappings for matching ignition timing and higher injection quantities when the engine runs on boost.

Gruber's final modifications around the engine included a polished stainless steel cover to shield the right leg from the red-hot turbocharger and a new exhaust system. Because he'd heard the three-tailpipe design of the standard exhaust roundly criticized by Rocket owners, Gruber fashioned a stunted version for his system-though it's also a three-pipe exhaust. Gruber adds, "Since I make the high-performance exhaust by hand anyway, I can fulfill the customer's individual desires regarding tailpipe length, design and diameter."

The huge amount of handiwork involved certainly explains the conversion's hefty price of 11,000 euros. You can find turbo kits from the USA for less money on the internet, but none of them has an intercooler or a European-type approval. And you also don't hear about a reinforced clutch, which is included in the Albrex conversion.

Gruber's vast experience with turbo engine development can be felt on the first ride. The engine doesn't show any cold running problems and demonstrates a robust but smooth power curve with the often-typical turbocharger lag at low revs. The combination of short headers and small charger is obviously worth the precision work. Power is in plentiful supply and first and foremost requires a cool and experienced hand on the throttle grip.

When you consider that the Triumph development engineers believed their customers could only manage an electronically restricted 147 lb-ft of maximum torque at 2,500 rpm, you can imagine what 266 lb-ft at an unbelievably low 2,900 revs can do.

The Rocket III's stock 240 section rear tire works well in the real world, but on the turbo version even 330 rubber would have trouble getting traction on the road. During our visit it was way too cold to run performance tests and the early winter roads of Wildschnau had the traction level of soft ice cream.

It certainly isn't the fault of the 22 pounds added by the turbo conversion that the bike is only about two- or threetenths of a second faster from 0 to 100 km/h than the standard 3-4 seconds in pite of 80 extra horsepower. But woe to the rider if the monster is really on the move-the road becomes a dragstrip, and the rider's left hanging on the handlebar like a spinnaker.

Before you've taken a deep breath-or, as promised by Gruber, in about 10.5 seconds-the needle of the speedometer has left behind the 200 km/h mark and it's time to make heavy demands on the standard Triumph two-rotor disc brake. Surprisingly, it works quite well.

The turbo Brit machine is certainly one of the most fascinating and entertaining ways to burn the distance between two corners. Accompanied by the whistling of the turbocharger, the motorcycle inexorably seems to head toward the horizon. It doesn't matter whether you choose third, fourth or fifth gear on a country road. The engine can always deliver more power than necessary, and when the rev meter jumps beyond 2,500 you should aim straight down the road and hold tight.

You can quickly get addicted to this style of riding. Pull the throttle, the boost rises, the engine catapults the bike forward and the next gear is engaged, accompanied by a wild chuffing of the pop-off valve on the right intercooler-and the fun goes on and on. Clutch, gearbox and shaft drive certainly are tackling some heavy lifting, and it's hard to return to cruiser mode as prescribed by law. But even then it's impossible to forget that 266 lb-ft of torque is at work. The power surplus is at once fascinating and dangerous. Each tiny turn of the throttle requires a great sense of balance and restraint.

The tuner also gave the bike an auxiliary ECU with a special mapping for the turbo engine. It is responsible for trimming the injection and ignition systems with painstakingly calibrated mappings for matching ignition timing and higher injection quantities when the engine runs on boost.

Gruber's final modifications around the engine included a polished stainless steel cover to shield the right leg from the red-hot turbocharger and a new exhaust system. Because he'd heard the three-tailpipe design of the standard exhaust roundly criticized by Rocket owners, Gruber fashioned a stunted version for his system-though it's also a three-pipe exhaust. Gruber adds, "Since I make the high-performance exhaust by hand anyway, I can fulfill the customer's individual desires regarding tailpipe length, design and diameter."

The huge amount of handiwork involved certainly explains the conversion's hefty price of 11,000 euros. You can find turbo kits from the USA for less money on the internet, but none of them has an intercooler or a European-type approval. And you also don't hear about a reinforced clutch, which is included in the Albrex conversion.

Gruber's vast experience with turbo engine development can be felt on the first ride. The engine doesn't show any cold running problems and demonstrates a robust but smooth power curve with the often-typical turbocharger lag at low revs. The combination of short headers and small charger is obviously worth the precision work. Power is in plentiful supply and first and foremost requires a cool and experienced hand on the throttle grip.

When you consider that the Triumph development engineers believed their customers could only manage an electronically restricted 147 lb-ft of maximum torque at 2,500 rpm, you can imagine what 266 lb-ft at an unbelievably low 2,900 revs can do.

The Rocket III's stock 240 section rear tire works well in the real world, but on the turbo version even 330 rubber would have trouble getting traction on the road. During our visit it was way too cold to run performance tests and the early winter roads of wildschnau had the traction level of soft ice cream.

It certainly isn't the fault of the 22 pounds added by the turbo conversion that the bike is only about two- or threetenths of a second faster from 0 to 100 km/h than the standard 3-4 seconds in pite of 80 extra horsepower. But woe to the rider if the monster is really on the move-the road becomes a dragstrip, and the rider's left hanging on the handlebar like a spinnaker.

Before you've taken a deep breath-or, as promised by Gruber, in about 10.5 seconds-the needle of the speedometer has left behind the 200 km/h mark and it's time to make heavy demands on the standard Triumph two-rotor disc brake. Surprisingly, it works quite well.

The turbo Brit machine is certainly one of the most fascinating and entertaining ways to burn the distance between two corners. Accompanied by the whistling of the turbocharger, the motorcycle inexorably seems to head toward the horizon. It doesn't matter whether you choose third, fourth or fifth gear on a country road. The engine can always deliver more power than necessary, and when the rev meter jumps beyond 2,500 you should aim straight down the road and hold tight.

You can quickly get addicted to this style of riding. Pull the throttle, the boost rises, the engine catapults the bike forward and the next gear is engaged, accompanied by a wild chuffing of the pop-off valve on the right intercooler-and the fun goes on and on. Clutch, gearbox and shaft drive certainly are tackling some heavy lifting, and it's hard to return to cruiser mode as prescribed by law. But even then it's impossible to forget that 266 lb-ft of torque is at work. The power surplus is at once fascinating and dangerous. Each tiny turn of the throttle requires a great sense of balance and restraint.

But for mature riders who don't want to struggle with the extra 200 kg of a Boss Hoss or who don't want to ride a rolling living room like a Gold wing, the bellows may be worth thinking about. Then again, this kind of riding has nothing to do with reason.

Albrex Rocket III Turbo

Fabrication/engineering:
Conrad Gruber, Albrex, albrex.com

Engine
2294cc, liquid-cooled inline triple with Albrex turbocharging system

Compression
8.7:1, max. boost 8.4 psi

Transmission
5-speed, reinforced multidisc clutch, shaft drive

Performance
0-62 mph in approx 3.1 sec.
0-125 mph in approx. 10.5 sec.
Max speed: Approx. 149 mph
Max power: 220 hp @ 5000 rpm
Max torque: 266 lb-ft @ 2900 rpm

Modifications
Albrex engine tuning with one KKK turbocharger in special Albrex con- figuration, integrated boost control and symmetrical Albrex intercooler system, Albrex high-performance exhaust system with special manifold, auxiliary Albrex ECU for ignition and injection

KKK supplied the turbo, but Gruber transformed the stock Rocket's triple-pipe setup into a cleaner, shortened dualexhaust version.
The turbo conversion isn't complete without two intercoolers.