The Ultimate Volkswagen/Audi Stage Tuning Guide (2024)

From the factory, Volkswagen and Audi vehicles offer solid performance, comfort, and quality. For some owners, there comes a time when the stock performance of their vehicle is no longer enough. Luckily the aftermarket support for Volkswagen and Audi models is extensive. Owners can make a few basic modifications for increased power and improved handling, or completely transform their car into a track machine.

At Alex’s Autohaus, we can assist you in the process of modifying your Volkswagen or Audi. Our performance specialists can recommend parts and upgrade paths to achieve the performance goals you have set for your vehicle.

Starting with Stage Tuning

When talking about vehicle upgrades, you may hear people refer to different “stages” of performance modifications. Primarily used when discussing turbocharged or supercharged vehicles, understanding what exactly each stage entails can be confusing.

Different tuning companies and vehicle platforms have different upgrade paths that vary greatly in the potential for power gains. We are going to dive into what stage tuning is through the lens of Volkswagen and Audi platforms.

What Does “Stage Tuning” Mean?

When people (or shops, or companies) use the term “stage”, they are generally referring to modifications that are done together to achieve a specific level of performance. The real answer to this question is it depends. There is no blanket description of what each stage is, and different vehicles have vastly different upgrade paths, and often cannot be compared to one another.

That being said, there are general modifications that occur on these upgrade paths that are associated with various stages. Generally, the earlier the “stage” the less involved the modification is, with later stages requiring a significant amount of work.

Read on to learn about the typical upgrades seen along the stage path, and learn how we define stages here at Alex’s Autohaus.

Stage 1

Stage 1 is the ground floor of the modification process. From the factory, most vehicles are not making the maximum possible power they can on the stock hardware. Modern vehicles are controlled by complex Engine Control Units or ECU. The ECU is essentially responsible for dictating how the engine should run. ECUs can be remapped, allowing the software to make better use of the hardware from the factory. A typical Stage 1 tune comprises of just an ECU remap with no upgrades to hardware.

The power output for a vehicle can also vary depending on the fuel grades available. Customers bringing their cars to us in Utah are limited to 91 octane at the pump, but those in other areas of the country where 93 octane pump gas is available will see even bigger power increases.

Stage 1+

Stage 1+ is more ambiguous, and what it entails will vary greatly depending on brand, car, shop, or individual.

Intake

At Alex’s Autohaus, a Volkswagen or Audi Stage 1+ upgrade involves the installation of an intake system. Smoothing the flow of air into the turbocharger/supercharger will allow for a faster spool and better throttle response. Intakes can further enhance the driving experience by amplifying induction noise in the cabin.

High-Pressure Fuel Pump

Depending on the platform, (particularly older Volkswagen/Audi FSI engines) the introduction of a high-pressure fuel pump will also be done at this stage. Taking care of fueling early on the upgrade path will not only improve performance, but it will tick a box needed when moving toward more substantial upgrades and power levels.

Injectors

Going back even further, the original 1.8t from the B5/Mk4 era in the late 1990s and early 2000s needs upgraded fuel injectors at this stage. The factory injectors are not able to keep up with the additional airflow from the tune/intake.

Stage 2

The previous stages addressed engine control, fueling, and pre-turbo/supercharger airflow. Moving into Stage 2 will open up the exhaust and address cooling issues often seen when running higher boost levels.  

Exhaust

While air now flows freely before the engine thanks to the modifications made in prior stages, exhaust gases leaving the engine are still restricted by factory pipe diameter and emissions control equipment. Before upgrading to stage 2 software, installing a larger diameter downpipe at a minimum is required. The ideal setup for this stage is a full turbo-back exhaust, allowing air to flow freely and giving your car a much more aggressive sound.

Intercooler

Another hardware upgrade done at the Stage 2 level is a larger, more efficient intercooler. Once the intake air has been pressurized by the turbocharger, the intercooler further condenses the air by reducing its temperature. Charged air will pass through the intercooler before entering the engine. Many vehicles come equipped with an intercooler from the factory, but once higher boost levels are being made, they become inefficient.

A condition known as heat soak can occur when running more power on a factory intercooler. The car will perform well and make full power initially, but once excess heat builds up in the engine bay, the factory intercooler will not be able to cool and condense the charged air as well. Hotter air means less power, but upgrading the intercooler to one with a larger core will help the car continue to make full power under harsh conditions.

Other Platforms

The above description of a Stage 2 upgrade follows what is seen on turbocharged vehicles. However, as discussed earlier, not all platforms have the same hardware upgrades. For example, on Audis equipped with the 3.0TFSI engine, Stage 2 involves installing new crank and/or supercharger pullies.

Stage 2 will entail different hardware upgrades depending on your platform, but in nearly all cases an ECU reflash will be required to take advantage of the changes.

Stage 3

After Stage 2 on turbocharged vehicles, the route to more power typically involves upgrading the turbocharger itself. A larger turbo will allow higher rates of airflow and typically shift the power band to later in the RPM range.

There are a lot of different options at this stage. On 2.0-liter EA888 EVO 4 motors, a larger turbo from higher output variants of the same engine can be used. 2022+ GTIs come factory with a Garett turbo, while the Golf R is equipped with a new Continental turbo. This new generation marks VW’s departure from ISI turbos, as those were notoriously unreliable.

Standard Golfs, Alltracks, and Sportwagons with the 1.8-liter version of the older EA888 Gen 3 motor can upgrade to either the ISI IS20 or the IS38. This type of OEM turbo upgrade bolts directly up to the engine and works with the existing modifications from previous stages, providing large power gains with relatively minimal invasive work.

Again, different platforms have different requirements. Older vehicles often do not have the same broad range of factory turbo sizes that work as a direct swap. For example, before making the switch to IHI for the Gen 3 EA888, the 2.0t and the early 1.8t engines utilized BorgWarner turbos, and the only direct factory turbo upgrade was from a K03 to a K04. 

Anything larger requires a larger non-factory turbo such as a GT28RS and an accompanying exhaust manifold, wastegate (if external), and coolant/oil lines.

Stage 3+

When power levels beyond what can be achieved at Stage 3 are the goal, on many platforms the engine will need to come out of the car to get built. Different engines run into issues at different points, but to avoid damage, upgrading the connecting rods, crankshaft, pistons, and other internals is necessary to move past Stage 3 power levels.

Depending on the platform, there are some “off the shelf” turbo and tune options available. 2.0-liter EA888 Gen 3 motors can upgrade to the Stage 3+ EFR7163 Turbo Kit from APR and still utilize an off-the-shelf tune. This upgrade would follow a similar pattern to the IS38/IS20 upgrades from the previous stages but recommends upgraded internals for safety.

There are also turbo kits available for the new EA888 EVO 4 motors, such as this upgraded Garrett option from Unitronic for MK8 GTIs.

Stage 3+ builds can include custom turbo setups, and these builds can’t be tuned with the same “off-the-shelf” tune used at lower stages. Standalone engine management and a custom dyno tune are sometimes needed to safely and effectively make power at this stage.

At Alex’s Autohaus, Stage 3+ encompasses a variety of custom projects. Any unique build, engine swap, or internal upgrades fall under the Stage 3+ umbrella.

Supporting Modifications

While making boatloads of power is awesome, it’s more important to make sure you can stay flat in the corners, scrub off all that extra speed (on the track of course!), and put that power to the road. Good quality supporting mods will make your car far safer and faster than raw power alone.

Brakes

Unless you began with a performance-oriented platform (and even sometimes when you do), the brakes from the factory are meant to function with the stock power levels. With hundreds more horsepower, you will reach higher speeds far more quickly. This leads to a lot of excess heat building up in the brakes.

Upgrading to larger pads and calipers will allow for heat to be better absorbed under heavy braking. Slotted or drilled rotors will also help bring temperatures down. Doing this will reduce the chances of your brake pad material disintegrating and glazing your rotors. Consistent and effective braking will not only make your car safer; it will lead to better times on the track.

Suspension

To maintain speed through corners, upgrading suspension components should be on the shortlist of supporting modifications. Shocks, lowering springs, or coilovers will keep your vehicle’s center of gravity, keeping it flat as you unleash all the new power carving up a canyon. Upgrading your sway bars will help reduce body roll and keep you from rolling over.

Depending on how you choose to modify your suspension, you can have flexibility in your ride height. Standard lowering springs and shock absorbers will provide you with a completely static ride height, but some coilover systems are adjustable, giving you flexibility in the ride height of your vehicle. There is a wide variety of suspension upgrades available for Volkswagen and Audi models that can improve the handling of a build whether it’s a streetcar or a track car.

Tires

The type of tire chosen for a car depends greatly on the conditions it will be driven. Generally, a wider tire will benefit cars with high power outputs, but as with everything on this list, it depends. If you run a car with lower power outputs on a tight and twisty autocross track, narrower tires will help the car remain nimble. High-speed and big power track/drag cars can benefit from a wider tire to help them put the power down.

The compound of tires is important to consider too. Super sticky summer tires will not only wear quickly, but they will also be dangerous if you live in an area that sees colder temperatures. Choosing a tire that will function well in variable road conditions will sacrifice performance. Deciding on a tire that will aid in both performance and function will greatly enhance your vehicle, particularly when it has been modified.

Transmission Control Unit Tune (DSG):

Volkswagen and Audi vehicles equipped with DSG/S-Tronic automatic transmissions require the transmission control unit to be remapped to support higher power outputs. In much the same way as the ECU, TCU tunes change what the computer is requesting of the transmission. The TCU tune will allow the clutches within the transmission to clamp harder, supporting much higher torque levels than stock.

A TCU tune will improve performance as well. The tune will change the transmission’s shift points to optimize acceleration and allow downshifts to happen at any gear if it can be done safely. Additionally, automatic upshifts can be removed, allowing gears to be held up to redline.

Clutch (Manual)

With more power and torque, vehicles with manual transmissions need to have a clutch upgrade to effectively put power to the ground. A performance clutch allows much higher power levels to be transferred from the engine to the wheels without slipping. An upgraded clutch will be able to take the abuse of hard-track driving far better than a factory one will.

Upgrading your clutch can make your vehicle more difficult to drive, but this comes with the territory of high-output project cars.

Driver

Your car makes tons of power, handles like a race car, stops on a dime, and sticks to the road, what could be next?

 The ultimate modification you can do to make your car faster is to become a better driver. There’s a common misconception that power is all you need to be fast, but the reality is a highly skilled driver in a slower car can put down faster lap times than a less experienced one with an extremely fast car. Get out on the track and take the time to learn your car’s characteristics, its limit, and how it drives.

Getting a good experience will provide you with the most significant increase in lap times, greater than any stage of power, brake, tire, or suspension upgrades.

Final Thoughts

The performance potential of Volkswagen and Audi vehicles is extensive. It can be hard to know where to start with so many options and platform variations out there. Luckily, we can help. Give Alex’s Autohaus a call or schedule an appointment to talk to one of our performance experts, or visit our tuning services page for an abbreviated version of this article and some tuning frequently asked questions.