EuroCode Tuning K04 Turbo - Tuner Tech

For all its high-tech, electronically controlled complexity, the elemental functionality of a modern engine has been remarkably unchanged since the 1876 introduction of Nikolaus Otto's four-cycle principles.

In simple terms, getting more air and fuel into the engine, packing it tighter, blowing it up and evacuating the gases is all it takes to enhance engine performance. In recent years, most manufacturers have made this easier by including forced-induction into their product lines.

In the entry-level European realm, Volkswagen's 1.8T reigns supreme among tuners and fans alike as an easy-to-modify powerhouse that begs to be boosted. Turning up the boost is as easy as an ECU upgrade that can be done in minutes at a tuner's shop. Going beyond the easy 25-40hp a chip offers, you may need to swap parts to overcome the engine's limitations.

Redondo Beach, CA-based EuroCode Tuning gave us an over-the-shoulders view as the crew upgraded this '03 Audi A4 1.8T quattro, fitting a K04 turbo upgrade that features Revo software, 225hp Audi TT injectors, front-mount intercooler and Samco hoses - all to prove that bigger is indeed better.

The polished K04 turbo is the mainstay of the VAG tuning industry. It offers good power with excellent driveability.

Product Overview
EuroCode's kit is based on Borg-Warner Turbo System's K04 - a turbo that needs no introduction as it's the mainstay of the VAG tuning industry. Thanks to its OEM pedigree, the K04's fit and finish are impeccable, and its larger size delivers more volume compared to a stock K03.

For high-boost applications, cooling the intake charge air is crucial for maintaining performance. When the turbo compresses the air, it causes it to heat up, resulting in a reduction of charge density. Engineers have tried everything to reduce intake charge temperatures on turbo cars, and most rely on a simple air-to-air intercooler.

An intercooler works much like an automotive radiator, transferring heat to the surrounding air by means of tubes, fins and passages. In this case, it's the intake charge that's cooled by its journey through the intercooler on its way into the engine.

VAG 1.8T Tuning Program
EuroCode's FMIC comes with all the brackets, plumbing and silicone hoses needed.

A stock 1.8T intercooler is small, shrouded from oncoming air and prone to heat soak. A large front-mount intercooler (FMIC) such as the one in this kit (2.25x10x18.5") can solve these shortcomings and looks cool peeking out from the front.

EuroCode goes a step further with mandrel-bent piping that's connected to the FMIC with triple-layer silicone hose and a specially machined piece to accommodate the factory MAP sensor. A Carbonio intake and Forge Motorsport dump valve, also sourced from EuroCode, round out the package.

Installation Highlights
Installing EuroCode's K04 conversion should take about six hours for an experienced technician. It requires intimate knowledge of how the car comes apart, along with basic mechanical skills. Although the process is reversible, installing the FMIC does require some internal trimming of the grilles. You should always have a Bentley manual at hand, and if there's any question, leave the job to a professional.

To install the intercooler, EuroCode provides a 21-page manual, so we'll gloss over the highlights. You need to remove the front bumper, fender liners, under tray and headlight/grille assemblies, followed by the intercooler. To make room, you have to trim plastic to clear the intercooler and power-steering cooling line, which is rotated upward from its normal horizontal position.

The existing MAP sensor is reused and bolts on to the FMIC intake pipe.

The kit comes with the plumbing for the intercooler, but you'll have to reuse your existing MAP sensor.

The turbo goes on just as a replacement turbo would. On this particular unit the cold side of the housing was polished and the hot side was ceramic-coated by Jet-Hot. Although not necessary, the exhaust manifold was also coated.

Dyno Testing
After spending a great deal of money, it's important to take full measure of the results, and the easiest way is with a chassis dynamometer. We chose to use Harman Motive in Torrance, CA, for both baseline and post-install runs.

Here's the FMIC in situ. Note the power-steering cooling line on the driver's side is turned upward.	Not for the faint-hearted, installing a FMIC requires removing the front bumper, grilles and headlight assemblies.	EuroCode's FMIC dwarfs the stock intercooler and is better positioned in the air stream.
The factory MAF sensor is unbolted from the factory airbox and mated to the Carbonio intake provided by EuroCode.	This Samco intake boot replaces the factory rubber piece. It both wears and flexes less.	Ceramic coating on cast exhaust manifold is pretty, although few will ever see it.
The polished K04 turbo is the mainstay of the VAG tuning industry. It offers good power with excellent driveability.	The test pipe (front) isn't legal for street use, as it replaces the catalytic converter.