To get gases flowing out as fast as they get pulled in, we used Eurosport's 2.5-inch downpipe, followed by a 2.5-inch cat-back exhaust. The downpipe utilizes a factory-style flex joint and laser-cut mounting flange to meet up with the turbo. The downpipe is rated at 10 hp and allows the turbo to spool faster. The cat-back system is a full stainless steel performance exhaust that utilizes mandrel-bent tubes and adds an additional eight hp. The sound is great, barely louder than stock at idle and cruising, but most noticeable at wide-open throttle. The sound is deep and a little raspy, not buzzy. You can really hear the turbo spinning on acceleration and the burble on deceleration sounds great.
The final piece we installed was the Eurosport underdrive pulley-a billet aluminum crank pulley that provides a slight underdrive, but is less than half the weight of the stock steel pulley. You don't necessarily pick up power at the crank, but less power is lost between the crank and the wheels. This is another piece that really has no downside.
With just a few well-chosen mods, we have taken our MkIV 1.8T from basic daily driver to a fun canyon-carving machine. The handling is now dialed in, we are putting down about 180 hp to the wheels, it stops well and looks great. For the enthusiast on a budget, the 1.8T is an excellent choice for a project build. For well under the price of a new VW, you can build something unique that fits your personal taste and performs just as well as a brand-new car.