The Best Audi S5 B9 Mods

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The Audi S5 B9 is the successor to the first generation S5, or S5 B8. It was first introduced in 2017 and is still in production today. It was built on the Volkswagen Group’s MLG platform and only offers a couple of engines: 3.0 TFSI and a 3.0 TDI (only in Europe). In this specific guide, we will be focusing on the 3.0 TFSI since this is the most popular engine for this model. Out of the factory, this impressive 3.0 TFSI twin-scroll turbocharged engine puts out 349 hp (245 kW) and 369 lb-ft (500 Nm). This is lighter and more powerful than the previous supercharged 3.0 V6 found in the B8 S5.

Ignition Coils & Spark Plugs

Before going into the mods below, we want to reiterate the importance of fresh ignition components before modding an engine. A lot of people don’t realize the effect old ignition coils and spark plugs have on an engine’s performance. Factory ignition coils and spark plugs are made for stock engine performance, or 350hp in this case, not 400hp+. For any bolt-on mods, factory plugs and coils should suffice. As a general rule of thumb, if your ignition components have over 15,000 miles on them, we would advise changing them before adding any mods. The last thing you want to do is put mods on and not feel an immediate increase in power.

Anyone running boost levels above stock levels, we recommend running 1-step colder spark plugs. 1-step spark plugs burn cooler, which prevents engine knocking, pre-detonation, or misfires and keeps engine temps down.

Buy Here: Audi S5 B9 OEM Ignition Coils
Buy Here: Audi S5 B9 OEM Spark Plugs

Purchase Here: 1-Step Colder S5 B9 Spark Plugs

How to Make Your Audi S5 B9 Faster – Audi S5 B9 Performance Modifications

• ECU Tune
• Downpipe
• Intercooler
• Charge pipe kit with upgraded BOV
• Air Intake

Some of the mods below are only for US S5 B9 fitment, so please make sure any of the mods listed below fit your exact build. 

1. Audi S5 B9 ECU Tune

ECU tunes will always be the biggest bang for your buck when it comes to modding an engine. The factory ECU is mapped for efficiency and reliability, not performance. Therefore an aftermarket tune, especially one like JB4, optimize the engine’s performance to get the most out of it safely. Typically tunes add 30-60hp on a stock engine, so it is a good foundation to build modifications on top of. They may seem expensive for a first mod, but it will be well worth it, you have our word. Benefits that can be seen with adding an aftermarket ECU tune:

• Increased engine efficiency and performance
• Driver customization
• Provides a cleaner burn
• Easy to install, for the most part

BMS B9 S5 JB4 Piggyback Tune

We are a huge fan of Burger Motorsports JB4’s because of their ease of use and installation. The JB4 for the B9 S5 also offers 8 different performance maps which allows the driver to customize their driving experience. Also, the JB4 isn’t VIN locked. Therefore, if you want to go back to stock and not void a dealership warranty, all you have to do is unplug it.

2. Audi S5 B9 Downpipe

A downpipe, often referred to as a DP, connects the turbo to the rest of the exhaust system. The factory downpipe has a very restrictive catalytic converter that hinders engine performance by producing more back pressure but keeps emissions down. Without a tune, a downpipe isn’t going to give crazy power gains. However, paired with a tune and some other bolt-on mods, a catless or high-flow catted downpipe can add up to 40hp+. There’s always a debate between catless vs high-flow catted downpipes.

Put simply, if you are in a state that takes emissions very seriously, be safe and go with the high-flow. If you are in a state where emissions is not the biggest issue, go with catless. The goal of a downpipe is to reduce as much back pressure as possible in the exhaust system.  Another popular debate is since a downpipe is typically just a metal tube, why not get one on ebay. Do not do this. Go with a tried and true aftermarket company because these are made to optimize performance and airflow.

ECS B9 S5 High Flow Catted Downpipe

Although ECS may be known as an aftermarket brand reseller, they have started to dabble in their own aftermarket parts in the last decade. Since they have been around for over 6 decades, they have seen all kinds of aftermarket products. We have high confidence that their experience and R&D warrant exceptional products at great prices. When paired with a tune, intake, intercooler, and charge pipe kit, the above downpipe provided max gains of 34whp and 41lb-ft of torque. On top of performance gains, it also adds a nice growl to the exhaust.

3. Audi S5 B9 Intercooler

An often overlooked mod when going for real power is an aftermarket intercooler. Do not get an aftermarket intercooler in hopes of gaining more power. It isn’t a performance mod, it is more of a reliability and efficiency mod. An aftermarket intercooler is much larger than the factory intercooler, specifically 134% larger for the Wagner Tuning intercooler, which means there is more surface area to disperse the heat. When more power is added to an engine, more heat is produced. Overall, heat soak becomes more of an issue when more power is produced. Heat soak is the power killer. If you are serious about power gains and engine longevity, an aftermarket intercooler is worth every penny.

Wagner Tuning B9 S5 Competition Intercooler

Wagner Tuning is a well-known aftermarket brand that has been around for 2 decades and builds parts for many other car brands. They specialize in intercoolers, so you know they build exceptional intercoolers. The unit above includes an intercooler that is 134% larger and provides 105% more volume compared to the factory intercooler. It also includes a charge pipe kit, which we’ll go more in-depth below, and we highly advise getting this kit as it is highly reputable. Lastly, this kit is 100% plug-and-play ready for installation.

4. Audi S5 B9 Charge Pipe Kit

Another restrictive factory unit is the charge pipe. A charge pipe connects the intercooler to the intake manifold. To get the full effect of an aftermarket intercooler, it is highly advised to upgrade the charge pipe. The goal of any engine when more power is produced is to increase airflow to the turbo. Factory charge pipes are typically plastic and can really only handle factory boost pressure and once boost pressure is increased, these restrictive pipes become a big bottleneck to engine performance. So once a tune, downpipe, and intercooler have been added, an upgraded charge pipe would be the next step.

Benefits to an upgraded charge pipe:

• Larger in diameter than the factory pipe
• Increased airflow to the turbo
• More turbo noise
• Upgraded material, typically aluminum
• Engine aesthetic is enhanced

ECS B9 S5 Post Throttle Valve Charge Pipe Kit

If you opt not to go with the Wagner Tuning intercooler + charge pipe kit, ECS provides a rather inexpensive post throttle valve charge pipe kit. Therefore from the throttle valve to the intercooler will be replaced with an aluminum charge pipe, high-quality silicone turbo outlet hose, and upgraded flanges. Due to the larger diameter tubing, you can expect this kit to increase airflow drastically and increase power output.

5. Audi S5 B9 Cold Air Intake

Lastly, and probably one of the most debated aftermarket parts, cold air intakes. Although cold air intake systems can be quite expensive, the increased airflow is overlooked. A cold air intake will not provide wild power gains on its own, but when paired with a tune, an upgraded air intake will provide increased airflow. On top of the increased airflow, it also provides a pretty sweet turbo spool noise in between gears.

Some people claim that dropping in a high flow filter into the factory intake does the exact same as an upgraded air intake. This just isn’t remotely the case. An upgraded air intake not only increases airflow, but also provides a quicker throttle response, faster turbo spool, and increases the efficiency of the turbo. Although may seem more expensive than the benefits, just pony up the extra money because you won’t regret it.

Luft-Technik B9 S5 Air Intake System

Luft-Technik is ECS’ brand as well. This intake system has undergone rigorous tests and claims to add 16hp and 15 lb-ft of torque. This is far more than normal but goes to show what an upgraded intake can do when paired with a tune. This system also comes with an upgraded turbo inlet hose, which is a very restrictive hose out of the factory.

Conclusion – Audi S5 B9 Mods

There are many aftermarket brands out there to choose from when it comes to the B9 S5, however, the ones listed above are probably our favorite out of the masses. After reading this post, we still advise doing your own research as many enthusiasts have different vehicle goals. With the above mods, your S5 B9 should be in the 415hp – 430hp range depending on what tune maps and fuel is used.

If you want to read up on more Audi B9 S5 content, here is the “Audi B9 S5 Ultimate Guide”.