Automotive scientists researching the evolutionary development of the Scion xB found evidence showing this little monster's gone through some serious changes in its very short existence. The first generation xB introduced to U.S. consumers in 2003 was found to be a mutated sibling of the Toyota bB, first introduced to the Japanese domestic market in 2000.
In 2005, the bB evolved in its native Japan - aspiring to be much more than a refrigerator on wheels - into a "car-shaped music player that incorporates youthful sensibilities," a quirky description used by Toyota. Whatever the meaning of that tagline, the bB has undergone significant exterior, interior and drivetrain transformations on the assembly line and further evolution in the able hands of Japan's own Blitz Co., Ltd., the parent of U.S.-based Blitz Performance Sales, Inc.
If improved evolutionary fitness guarantees the survival of the species, as proposed by Darwin's theory of natural selection, then the Blitz bB will certainly be regarded as the champion of its kind. Undeveloped, the second generation bB comes equipped with either a 1.5 liter (109 hp) or a 1.3 liter (92 hp) 16-valve VVT-i four-cylinder engine, not nearly enough to impress the sophisticated urban female. Thanks to the genetic engineers at Blitz, this offspring received some desirable traits that make this specimen different from the others.
Beneath its sinister exterior is an even more menacing supercharged four-cylinder engine, which greatly improves the displacement to output efficiency by converting kinetic energy from engine rotation into thermal energy released during combustion. Simply put, some of the engine's power is converted to create a more powerful internal explosion, which, through the pistons and connecting rods, causes the crankshaft to turn more forcefully.
Toyota provided the engineers at Blitz with a solid platform for producing more power. This 2006 bB came equipped with the 1.5L, 3SZ-VE engine, a relatively new engine family produced by Daihatsu of all companies, which offers a cast-iron block in lieu of the Scion xB's aluminum block. Although heavier, the cast-iron block is better suited for forced induction since the volumetric increase following combustion is less likely to have damaging effects on the stronger cylinder walls. The bore and stroke measures 72mm x 91.8mm respectively, contributing to a relatively high compression ratio of 10.0:1, somewhat of a disadvantage when considering something that'll ultimately be force-fed. In general, a compression ratio of 9.5:1 or lower is more conducive to supercharged and turbocharged applications because it allows for higher boost pressures with a reduced likelihood of detonation. However, changing the compression ratio would require complete reconfiguration of the bB's bottom end, something the casual tuner would likely avoid. Instead, Blitz uses a Roots-style positive displacement supercharger dubbed Compressor System C7, still in the R&D phase for the bB, which takes into account the higher compression ratio and delivers a lower and safer boost pressure. Blitz engineers optimized the performance of the forced air induction on both the intake and exhaust sides by adapting some of their most respected products to this new system. Now is a good time to mention what's in store for the 2008 U.S.-spec xB - 55 more horsepower and an optional sequential shifting automatic transmission to be specific. The tC's 2.4L engine will be lent out to the wider, longer and albeit heavier xB. One can only wonder what Blitz will make of this.
The Blitz SUS Power Core Type air cleaner was fitted to the intake system to provide ample amount of incoming air while reducing cavitations in the flow path. The entire air cleaner assembly is made of 200-micron T-304 stainless steel mesh, delivering enough air volume to produce over 1,000 hp, an apparent overkill for the bB. This highly corrosion resistant material is well suited for open element intake systems. Although open element systems are inherently exposed to engine heat more so than the factory air cleaner assembly, the modifications were necessary to deliver sufficient intake air to the supercharger. Separating the air cleaner from the engine's heat by building walls and using the hood as a seal would have reduced the heat exposure; however, positioning the air cleaner elsewhere and increasing the intake air tubing length might have altered the performance characteristics of the engine. Varying tubing lengths can often change horsepower and torque figures. The Blitz system delivers a rather balanced performance gain in both of those measures.
On the post-combustion side, the performance masters at Blitz opted for the free-breathing NÜR-SPEC DT axle-back stainless steel exhaust system. The two-piece kit utilizes a slanted mounting design to eliminate unnecessary bends. Where required, the 2-inch exhaust tubing is mandrel bent to minimize flow obstruction. The muffler assembly is both visually and audibly attractive with a polished stainless steel finish, a 4.5-inch diameter chimney pipe exhaust tip and an aggressive tone.
All this translated into a good day at the dynamometer for our beloved specimen. Although not quite enough to allow membership into the distinguished 1,000-plus horsepower club, the performance gain is rather remarkable considering the proportional improvement in both horsepower and torque. The maximum rate of power application increased by just over 30 percent measuring 144 hp at 6,100 rpm. Torque also went up nearly 40 percent from 104 lb-ft at 4,400 rpm to 143 lb-ft at 4,000 rpm. We can only fantasize about what horsepower figures would be like had the engine made that same torque at 4,400 rpm or higher, since the same torque at higher engine speeds yields higher horsepower.
Transferring that power to the road are the Blitz bB's 225/35-R18 Dunlop Le Mans LM703 tires mounted on 18x8 Blitz Racing Wheel Profile 08 Metal Silver wheels. Although the +45mm offset wheels fill up the wheelwell distinctively, they aren't exactly available in the four-bolt, 100mm configuration. These were specially made for this bB. Naturally, a sleek and attractive look like this cannot be achieved by simply replacing the OEM wheels with large diameter aftermarket sets unless attraction is defined as some sort of guilty pleasure associated with the enjoyment of steamrollers. Blitz's Super Flex Suspension is the perfect complement that brings the hub center two inches closer to the fender. The result is an enviable fitment and ride height that would make grandma look cool.
Proving adaptation is a sign of evolutionary success, this urban bB is outfitted with an attractive six-piece body kit, equipped with an optional factory navigation system and a standard nine-speaker audio system that employs multi-mode beat-sensitive illumination around five of the nine speakers including convenient armrest-mounted sound controls - noteworthy backups in case the 144hp supercharged power plant fails to impress.
Although rightfully excluded from the elite club of Subaru STIs and Mitsubishi EVOs, the Blitz bB stands in a class of its own for distinctive styling, exciting performance and superior quality engineering. Also, while those cars are attainable at their respective car dealers, this bB will never reach the U.S. market since the evolutionary process has predestined Scion's xB to become something entirely different beginning with the 2008 model year. Let the evolution proceed.