When someone mentions Audi in the context of modified cars, B8 A4s, B5 S4s, R8, anything with 5 cylinders and the like usually come to mind. Often way down on this list is the B6 A4 1.8T Quattro, if it’s available at all. Not for any intrinsic reason, it’s a great car and has many features that make it easy to improve on other Audi models in terms of performance.

However, as it sits between the ‘classic’ B5 and the more modern and recently very affordable B8 chassis, the B6 can quickly be overlooked. Despite its more popular siblings, there’s a ton to like about the B6 A4’s rounded styling and plenty of performance to be had from the four-cylinder turbo ahead of its front axles.

Today, we look at what you can do to make your B6 A4 turn heads and remind enthusiasts why it can be such an incredible platform.

Engine/Exhaust While only producing 170hp from the factory, the 1.8T is perhaps the most common modified engine produced by VW/Audi, regularly gaining around 100hp from simple bolt-ons and tuning. The nearly 250 hp packed into the B6 A4 with manual transmission and Quattro AWD system is nothing to laugh at, and will certainly keep up with today’s impressive performance figures from even the most ordinary commuter cars.

Here’s how to get there with your B6 A4. Naturally, the first step in your quest for more favorable power figures is an improved performance pickup. While we’ve mentioned this a few times, it’s worth noting that cold air intake won’t be a game changer on its own. What it will do is allow you to improve the engine in other areas and take advantage of all the potential power benefits they have to offer.

The cold air intake upgrade helps improve airflow and lower intake air temperatures so you can ensure the 1.8T breathes enough air to support more power.

IntercoolerThe real hero when it comes to lowering intake air temperature is the intercooler. The larger front-mount intercooler on your B6 A4 will help keep your intake air cool with some modifications we’ll add to this list. However, on its own, the FMIC upgrade will provide a slight increase in the performance of your Audi.

Diverter ValveThe diverter valve, or DV, releases pressurized air from the turbo when the throttle is closed to prevent the compressor from surging and damaging your engine. On the 1.8T of the B6 A4 the DV is a common source of boost leaks and needs to be replaced when this happens.

Fortunately, with an upgraded diverter valve, you can solve this maintenance issue and improve performance with a DV that provides higher boost and supports your other upgrades.

Turbo-Rear ExhaustThe final physical upgrade that allows you to achieve impressive horsepower gains from your 1.8T is the turbo-rear exhaust. From the exhaust side of the turbo to the mufflers, the turbo-back exhaust is a complete system. With a larger, freer-flowing and less restrictive exhaust, you can push out a larger volume of exhaust gases and gain some power. However, you will need to upgrade your engine software, but that’s the next step on the list.

Software upgradePerformance engine software tunes will improve your engine performance by itself, perhaps more than any upgrade on this list, but its biggest benefit is maximizing the efficiency of all the upgrades we’ve already mentioned. By telling the engine the new capabilities it has with other upgrades, you can tune the engine to take the performance benefits of those upgrades.

Without a software update, your bolt-on modifications won’t offer much in the way of power gains because the engine won’t realize how much more it can produce knowing what these parts can do.

DrivetrainWith a gain of around 100 hp, you’ll need to make a few future-proof upgrades to handle that additional horsepower. While 250hp isn’t a lot, your B6 A4 isn’t designed to handle that. In particular, your clutch and drivetrain linkages are not designed to handle this.

You’ll want to replace your factory clutch with a Stage 2+ unit rated at roughly 300 hp/tq to give yourself some headroom.

When it comes to engine mounts, transmission bearings, and drivetrain bushings, you’re losing a lot of your new strength to deviate from the factory rubber units. Upgrading to stiffer mounts and bushings allows you to reduce or eliminate this deflection, so all your available power is sent to the wheels for a more responsive driving experience.