The VAG 1.8-liter turbo might be the most transplanted, wrenched-on, tweaked, rebuilt and dynoed engine of the last 5 years. What started with ECU and then K-04 turbo swaps mushroomed into wastegates, blow-off valves, intercoolers, exhaust manifolds and 3-in. exhaust systems. The list of new and improved goodies grows exponentially by the month, and, as witnessed by the recent 1.8T Challenge, the path to huge horsepower numbers is varied and open to one's imagination.
And that's exactly what makes this car so unusual. On first glance, one would think it's yet another tire-melting 1.8t or a more ambitious turbocharged VR6, although these days even that's not unique. What actually motivates this exceptionally clean Golf 1.8t is a head from the 16V that Volkswagen gave up on when it introduced the MkIII series.
EIP first turbocharged a 16V in 1997, and the informed might remember that EIP was also the first to turbocharge the VR6 beyond anyone's belief. So when a customer came in with a stock 1.8t Golf and asked for something "different," Rich Cavacci and his crew at EIP happily obliged by applying their 16V expertise with the most up-to-date turbocharging components.
One of the major advantages of the older 16-valver was its forged crank. The 20-valve engines use cast cranks, and EIP has bent more than a few when it stressed the engines with high horsepower. To head off that problem, EIP machines the older forged cranks to fit inside the 1.8-liter block.
Also fit into this particular 1.8-liter block were EIP's forged pistons and 4340 chrome-moly connecting rods. With the 92.8mm crank's longer stroke, the engine was bumped from 1.8 to 2.0 liters. The 16V head was ported and O-ringed, and the original intake manifold was thrown out in favor of a custom, sheetmetal intake manifold that utilizes a 75mm throttle body. A copper gasket sits between the block and the head, and the engine is kept tight by a set of high-tension studs.
The stock injectors were replaced with higher-flowing units. Fuel streams through upgraded fuel lines with the help of EIP Competition Series fuel pumps, an Aeromotive fuel pressure regulator keeps gas flow precise, and a custom fuel cell replaces the stock tank. Because the original engine management system would have had no idea how to monitor or control the long list of modifications applied to this engine, EIP used an Electromotive Tec III programmable engine management system.
A Turbonetics T Series ball-bearing turbocharger helps cram extra air into the chambers. It's augmented with a Turbonetics Delta wastegate and a Blitz blow-off valve. The T Series turbo is mounted on a custom-cast turbo manifold designed by EIP. Instead of just using one of the many well-designed and undeniably efficient air-to-air intercoolers available, Cavacci and his mad scientists took it a step further and installed a Spearco water-to-air unit for even lower intake temperatures.
Using this setup allowed EIP to mount the intercooler closer to the engine, resulting in minimal pressure loss. The Spearco unit is supported by EIP's water-to-air radiator, an intercooler water pump and an EIP intercooler fluid reservoir. On the back end, the exhaust spews through a 3-in. EIP stainless-steel downpipe and downpipe-back exhaust system capped with a resonated tip.