Few things in the material world are as exhilarating as a purpose-built race car. While many dream about building one, most find modifying a street car far more affordable - and practical for that matter - seeing as how most lack the big corporate backers to offset the cost. Perhaps all is better off this way, but if daydreaming is a definite prerogative, here is something from AVO Turboworld that will decidedly instill the ring of a lullaby in your ear, maybe even a love song.

The righthand drive, 600hp AVO Subaru Impreza WRX STi demo car is crammed with the most extensive list of features to meet the challenges of even the most demanding race circuits and still leaves room for sporting a striking exterior. Without admitting to the popularly demonized shallow nature of physical attraction, the noticeably wider body of the AVO STi is far more attractive than its factory built counterpart. Not that there is anything wrong with a narrow rear end, but in terms of packing tires and gripping the road, the added width is undoubtedly preferable. In this case, the wider body allows for the fitment of a set of 265/35R18 Dunlop Direzza Z1 tires mounted on custom built +18mm offset 10-inch wide Rays Gram Lights. By comparison, Subaru installed 225/45WR17 Bridgestone Potenzas on '05 WRX STi models sold in the United States.

The chassis of the widebody AVO STi is a combination of lightweight carbon-fiber composite and sheet metal. The car began life as an Impreza WRX STi Spec C Type-RA, available only in the Japanese domestic market, but the lightweight, no-thrills, rally-going production body has been significantly transformed. The hood panel is a lighter and stiffer carbon-fiber replacement of the factory aluminum. The wider front panels are bolt-on custom-formed steel fenders, while the wider rears are cutout replacement custom-formed, welded and blended overfenders. Custom carbon-fiber bumpers are matched to the wider front and rear body panels. Fiberglass side skirts from a custom mold complete the distinguished look.

At the heart of the AVO STi is a new 2.5L, Cosworth-built, Subaru EJ257 high-performance long-block assembly. The EJ257 incorporates a semi-closed deck, a Subaru modification that facilitates boost pressure in excess of 10 psi. The advantage is that semi-closed deck engine blocks are less susceptible to cylinder wall flex thereby reducing the probability of premature head gasket failure. The CS600 is precision built with Cosworth and STi components. Forged pistons and forged H-beam connecting rods are mated to a STi crankshaft, which ride on high-performance trimetal rod and main bearings. The five-axis CNC ported cylinder heads with 1mm oversized intake and exhaust valves improve intake airflow by 22 percent and exhaust gas flow by 44 percent, when compared to the stock STi cylinder head. The heads are bolted to the block with 11mm steel studs and sealed with multi-layer steel head gaskets. The AVCS STi heads are also fitted with a number of other upgrades; high-performance valve springs and titanium retainers permit a 10,500rpm redline. The 10.9mm intake and 10.28mm exhaust high-lift camshafts support 278 camshaft degrees of intake and 274 camshaft degrees of exhaust duration respectively. This $12,000 upgrade, available through AVO Turboworld and other Cosworth distributors, is assembled with the utmost care using the finest Cosworth components to make it synonymous with perfection and reliability.