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The Audi A4 B7 is the successor of the A4 B6 is the A4’s third generation. It was first introduced in 2004 and produced up until 2008. It was built on the Volkswagen Group’s B7 (PL46) platform and offered many different engines: 1.6, 1.8T, 2.0T FSI, 2.0T TFSI, 3.2 V6 FSI, 1.9 TDI, 2.0 TDI, 2.5 V6 TDI, 2.7 TDI, and 3.0 V6 TDI. In this Audi B7 A4 mod guide, we will be focusing on the 2.0T engine. The 2.0T engine features a K03 turbocharger and puts out 197hp and 206 lb-ft of torque.
Ignition Coils & Spark Plugs
Before going into the mod list, it’s important to cover ignition coils and spark plugs. Moderately to highly used ignition coils and spark plugs can dampen an engine’s performance dramatically. Ignition coils and spark plugs out of the factory are built for stock engine performance, and don’t perform well with extra power. For any bolt-on mods, excluding tunes, factory coils and plugs usually suffice. However, when you start pushing 30hp over stock levels, you’ll want to get high-performance spark plugs or 1-step colder spark plugs. As a general rule of thumb when modding an engine, is if the ignition components are older than 15,000 miles, we would advise changing them before adding any mods.
Anyone running boost levels above stock levels, we recommend running 1-step colder spark plugs. 1-step spark plugs burn cooler, which keeps engine temps down and prevents engine knocking, pre-detonation, or misfires.
Purchase Here: Audi A4 B7 2.0T 1-Step Colder Spark Plugs
If you need assistance in looking for parts on another A4 B7 engine, reach out in the comments and we’ll give recommendations or write another engine-focused guide. Brands that will be featured include: APR, ECS Tuning, Raceland, and more. Before ordering any parts listed below, PLEASE make sure they fit your exact setup.
How to Make Your Audi A4 B7 Faster – Audi A4 B7 Mods
- ECU Tune
- Cold Air Intake
- Turbo Inlet Hose
- High Flow Cat
- Catback Exhaust System
- BONUS: Suspension
1. Audi A4 B7 ECU Tune
The biggest bang for your buck when it comes to modding an engine is going to be an ECU tune. Tunes are a great foundation mod to build on. Although a little expensive, they will surely give your engine the most power to start with. Stock ECUs aren’t optimized for performance and getting the most out of the engine. There are optimized for efficiency and reliability, which tends to be quite a bit less power than the engine can handle. There are many benefits to an ECU tune:
- Increased engine efficiency
- Increased engine performance
- Driver customization
- Provides a cleaner burn
- Easy to install, for the most part
APR tuning is a company that has been around for many decades creating exceptional aftermarket parts for German automobiles. With this ECU upgrade, power gains can range from 40-65hp and 75-105 lb-ft of torque, depending on the type of fuel used. This is pretty substantial for just an ECU tune. Also, with this tune, there are 5 different modes of performance a driver can choose from. However, the downside is that, if purchased, you must ship your chip to Ohio, or if you happen to live near Ohio, you can drive to their facility.
2. Audi A4 B7 Cold Air Intake
This is going to be a hot topic, is a cold air intake worth the money? Many enthusiasts believe an air intake is not worth the money for the lack of benefits they offer. However, in our minds, they are well worth it when paired with a tune. A high-performance drop-in filter just doesn’t have the same benefits as a high-quality cold air intake system. For beginners, a cold air intake brings outside air into the engine’s intake manifold. In short, the more power the engine produces, the more air the engine will need. Although the Audi A4 B7’s factory air intake is not bad, it is certainly more restrictive than a Luft-Technik system.
Aftermarket intakes may only add 5hp or 5lb-ft of torque, but that isn’t the major benefit of an aftermarket intake system. The main benefit is the major increase in airflow.
Since ECS Tuning has been around since the 60’s, they understand aftermarket parts and decided to create their own brand, Luft-Technik. Their engineering team has spent countless of hours on R&D to develop an intake system that has a direct correlation with performance when paired with a tune. This intake system adds 5hp and 5lb-ft of torque when paired with a tune. It is powder coated with a heat-shield, an easy install, and larger than the OE system.
3. Audi A4 B7 Turbo Inlet Hose
A turbo inlet hose is a tube that connects the air intake to the turbo. An aftermarket turbo inlet hose is a great alternative for those that don’t want to replace their entire air intake system. The OE corrugated unit is made from rubber and can be susceptible to ripping over time. It also is not designed for performance or modification.
This hose does not work with the intake listed above. Again, this is an alternative for consumers that don’t want to purchase the entire intake system. This silicone turbo inlet hose paired with a high-performance filter will slightly increase airflow, which would increase engine performance.
4. Audi A4 B7 High Flow Cat
A catalytic converter, often referred to as a cat, is found in a vehicle’s exhaust system and it essentially pushes out cleaner emissions through the exhaust. However, a factory catalytic converter restricts quite a bit of airflow and increases back pressure, which we know dampens engine performance. The OE cat is also very large and heavy. There are many benefits to an aftermarket cat, specifically a high flow cat:
- Reduces back pressure
- Turbo spools sooner
- Allows for easier airflow
- Noticeable engine performance gains
After installation, the check engine light may come on because the engine is sensing more emissions being emitted. Therefore, depending on the consumer’s location, an aftermarket cat may not fit into emission laws.
CTS Turbo is another aftermarket company that has been around for a while and it creates exceptional products for 9 automotive brands, including VW and Audi. Not only does this high flow catalytic converter increase engine performance, but it also adds a nice deep exhaust tone. Installation of this hi-flow cat is seamless.
034Motorsport was founded in 2005 and has been focusing on Audi’s, VW’s, and BMW’s ever since. This high flow cat is a direct fit to the stock turbo and exhaust. On a stock turbo tune, 034Motorsport claims this high flow catalytic converter adds 33whp and 27wtq.
5. Audi A4 B7 Catback Exhaust System
Another heavily debated topic is if a catback exhaust system is worth the money. Honestly, the performance gains seen from an aftermarket catback exhaust do not warrant the cost. However, who doesn’t like a deeper, more aggressive-sounding exhaust, unless that is you are going for a sleeper B7 A4. On top of sound, aftermarket catback exhausts slightly reduce backpressure.
6. BONUS MOD: Upgraded Suspension – Audi B7 A4 Mods
Last but not least, we know this isn’t an engine modification, but an upgraded suspension might be needed for a 14-18-year-old vehicle. Coilovers consist of a spring and a coil wrapped around a shock absorber that typically offers ride height adjustability and dampening. A sway bar, or stabilizer bars, is another important part of a vehicle’s suspension. It helps your vehicle handle turns better and prevents body lean.
Raceland has been producing exceptional coilovers at a low cost for many years. These specific coilovers are designed for the B7 A4 quattro setup. They allow adjustable vehicle drop of 1-3 inches, a stiffer ride, and a better driving experience.
H&R was created 4 decades ago to build suspension parts for many different automobiles. They provide exceptional suspension products at a relatively low price. These sway bars are adjustable, use special steel, and are more resilient than the OEM sway bars. They reduce body roll, increase lateral stiffness, and improve handling.
Conclusion – Audi B7 A4 Mods
There are many aftermarket brands that create exceptional Audi B7 A4 mods, however, the ones listed above are just our favorite choices out of the bunch. As with anything, we highly advise doing research outside of this article to ensure your vehicle goals will be met. With the above mods, an A4 B7 should be close to pushing 250hp, if not more. If you want to get really crazy and love your A4 B7 too much to get rid of it, we’ve seen enthusiasts upgrade the K03 turbo with a K04 turbo. These setups can run up to 350hp on 100 octane, but are very expensive.
If you want to read up on more Audi A4 B7 content, here is an article on “The 7 Most Common B7 Audi A4 Engine Problems”.