The Definitive Guide to building your VW 2.0T FSI Bottom End

Integrated Engineering’s complete guide to avoiding engine block failure in your MK6 Golf R and MK5 GTI

Key Takeaways:

  • Direct Injection & Timing Belt: The VW 2.0T FSI engine is known for its direct fuel injection system (FSI) and uses a timing belt instead of a timing chain, differentiating it from newer TSI engines.
  • Popular Models: This engine is found in various Volkswagen and Audi models, including the MK5 GTI, MK6 Golf R, Audi A4 (B7), and more.
  • Stock Weak Points: While the 2.0T FSI engine has a strong foundation, components like the connecting rods and pistons are known weak points, especially when pushing past 350 HP.
  • Upgrading for Performance: To safely increase power output, upgrades such as stronger connecting rods, pistons, and ARP hardware are essential to prevent engine block failure.

Integrated Engineering Support: IE offers a comprehensive range of performance parts and expert advice to help you build a reliable, high-powered 2.0T FSI engine.

What is the VW 2.0T FSI Engine (EA113)?

The 2.0T VW engine in the MK6 Golf R and MK5 GTI  is commonly referred to as the 2.0T FSI, TSI, and TFSI (EA113). The most important factor differentiating the EA113 engine from other VW engines is that this engine is direct-injected and has a timing belt as opposed to timing chains. Newer versions of the VW 2.0T (MK6 GTI, MK7 GTI, for example) have timing chains.

Popular Volkswagen and Audi models that have the 2.0 FSI engine are as follows:

  • Volkswagen MK5 GTI/GLI
  • Volkswagen MK6 Golf R
  • Passat 2006-2010 (B6)
  • EOS 2006-2015 (1F7)
  • Audi A4 2005-2008 (B7)
  • Audi TT & TTS (MK2 - 8J)
  • Audi A3 (MK2 - 8P)
  • Audi S3 2006 - 2013 (MK2-8P)
  • Audi A6 2005-2011 (C6)
  • Audi A6 Allroad 2005-2011 (C6)

How to Upgrade Your 2.0T VW FSI Block

The purpose of this in-depth article is to educate you on the 2.0T FSI bottom end in stock form. We will discuss how to upgrade it correctly to meet your performance goals, and provide you with Integrated Engineering product suggestions to help with your custom build.

If you have any further questions please feel free to contact us or leave a comment below.

Engine Block

The most common part number prefix denoting the correct block is 06F. Most 2.0T blocks are interchangeable. However, there may be slight differences between blocks such as the thermostat housings. As a rule of thumb, the best way to ensure a hassle free build is to start with the same block code that your car originally came with.

Main Caps & Bearings

Like most VAG 4 cylinder engines, the 06F block uses 5 two-bolt main caps. There are 4 outer main caps and one center main cap that contains the crankshaft thrust bearings (also called thrust washers). Most stock main caps are cast iron and can be upgraded to IE’s billet steel main caps as power output increases (more on this upgrade later). IE stock main bolt & thrust bearing part numbers:

  • Main Bolts - M10x80mm (OEM PN: N90130001)
  • Thrust Bearings (OEM PN: 06A105637A)

Crankshaft

  • All 2.0T FSI stock cranks have a stroke of 92.8mm and are all forged.
  • The timing belt drive gear is attached with one large bolt (crank bolt) and crankshaft damper is attached to it with a 6 bolt interface.
  • Also on the crankshaft is the trigger wheel which is used in part with the crank position sensor to determine engine RPM. It is very important that the trigger wheel does not get bent, as that will affect the engine RPM pickup. If the trigger wheel is removed for any reason, it must be replaced (one-time use). The bolts that fasten the trigger wheel to the crankshaft are also one-time use.
  • Most 2.0T FSI crankshafts are interchangeable except for B7 Audi A4 Quattro with automatic transmission.

Connecting Rods

  • All 2.0T FSI connecting rods measure 144mm on the center-to-center dimension (length) and have a big-end journal width of 24.90mm. The journal width dimension is important because newer timing chain driven engines (2.0T TSI GEN 2/3) are narrower in this respect.
  • Wrist pin diameters vary between engine codes and vary from 20mm to 23mm, depending on specific model. The most common wrist pin size for standard 2.0T FSI engines (MK5 GTI, for example) is 20mm.

Pistons

  • Most 2.0T FSI pistons are forged but are still not as robust as aftermarket forged pistons.
  • The stock bore size of 2.0T FSI pistons are 82.5mm.
  • Most pistons employ a 20mm wrist pin, except for higher output models which have 21mm or larger.
  • The stock compression ratio varies from 9.5:1 to over 10.0 depending on engine code.
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This section will be separated by different horsepower levels. Our goal is point you in the right direction to make your build a success.

350+ HP/TQ Connecting Rod & Piston Upgrades

At this power level, we recommend upgrading the connecting rods at a minimum. You can often maintain the stock pistons as long as the piston skirts and cylinder walls are in good shape. In high mileage blocks it may be a good idea to use over-sized pistons so the piston-to-wall clearances can be set correctly. However, replacing pistons and performing the required machine work can become expensive quickly.

It is certainly possible to surpass the 350 HP/TQ level on stock rods and pistons, but if longevity and reliability are of high importance to you, we do not recommend it for a long period of time.

It is common knowledge that 2.0T FSI connecting rods are a weak point of this engine. That isn’t to say that they were designed poorly but very often cannot handle the added stresses introduced by larger turbos and aggressive ECU tunes.

Two main reasons for connecting rod failure:

  • A very narrow beam design that leads to bent rods under high torque loads
  • Stock rods have an inferior metal composition. They are typically made from sintered iron compared to far superior forged steel aftermarket rods.

There are two available “drop-in” connecting rod options for use with stock pistons on 2.0T standard output engines:

  • Standard blocks will typically require 144x20mm connecting rods that have a tapered wrist pin. For high mileage applications, we recommend using rifle drilled connecting rods which promote wrist pin longevity. 

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*NOTE - For special edition or high output engine models (models exceeding the 200HP & 207 lb-tq) you will commonly have to upgrade rods and pistons together as drop-in rods are not available for wrist pins larger than 20mm.

Connecting Rod Rifle Drilling

Rifle drilling is an oiling hole that travels the length of the connecting rod beam from the big end (crankshaft journal) to the small end (piston wrist pin) of the connecting rod. Additional pin oiling has been shown to greatly extend bushing life on daily driven or high mileage applications.

350+ HP/TQ Engine Hardware

VW FSI ARP Rod

At these power levels the stock hardware, such as main bolts and head bolts, are adequate.

One important fact that builders often overlook however is that many stock bolts are stretch bolts and can only be used once. In other words, once the bolts are removed from the engine, they must be replaced with new/unused units.

*Note - there are also several ARP performance engine hardware options available that are stronger and reusable. See the next power section for more details.

Common OE bottom end hardware that are one-time use and must be replaced are:

  • Head bolts (10) (OEM PN: 06D103385D)
  • Main bolts (10) (OEM PN: N90130001) Flywheel bolts (6) OEM PN: N90665001
  • Crank damper bolt (1) OEM PN: WHT005322
  • Crank damper pulley to timing gear bolts (6) OEM PN: N91143901
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400-500HP/TQ Connecting Rod Upgrades

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To ensure reliable operation at power levels exceeding 400HP we strongly recommend upgrading to Integrated Engineering connecting rods and aftermarket pistons. Most aftermarket 2.0T FSI pistons utilize a non-tapered 20mm wrist pin 144x20mm connecting rod.

Available IE Connecting Rod Options:

  • H-beam 144x20 - Proven strong and reliable
  • H-beam 144x20 rifle drilled - strong and reliable with added wrist pin longevity from rifle drilling I
  • Tuscan I-beam 144x20 - Our highest quality connecting rod, strong and reliable, superior strength to weight ratio, included rifle drilling for added wrist pin longevity

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400-500HP/TQ Piston Upgrades

  • Mahle pistons - The best option for street builds and daily drivers, quiet piston operation, tight piston-to-wall clearances due to low expansion alloy.
  • JE pistons - a great option for street or track use, uses a tough 2618 alloy piston forging, a huge amount of bore sizes and compression ratios are available. AVAILABLE HERE

400-500HP/TQ Crankshaft/Timing Gear Interface

The 2.0T FSI timing interface is a great improvement over prior generation 4 cylinder engines. The most common failure point still remains as the timing gear located on the snout of the crankshaft. If the stock gear fails, your engine will lose timing leading to an expensive repair. To rectify this problem, we have developed an ARP crank bolt that increases the amount of force securing the gear in place.

  • IE/ARP crank bolt (This bolt is also reusable and does not need to be replaced) IE PN: ARP-06A-01

400-500HP/TQ Engine Bearings

We highly recommend using performance main bearing and rod bearing as power levels increase. The main advantage of performance bearings is due to a tri-metal composition they are able to withstand added bearing loads and are better suited to withstand crankshaft flex.

  • Mahle Motorsport Main Bearings
  • Mahle Motorsport Rod Bearings
  • Standard Thrust Bearings (OEM PN: 06A105637A)

Shop Engine Parts

400-500HP/TQ Engine Hardware

At this power level, the stock hardware is typically sufficient as long as it is never reused. If you plan on pushing the car further in the future you may want to consider to upgrading to ARP engine hardware. As an added bonus, ARP hardware is reusable and does not need to be replaced if removed.

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500+ HP/TQ Connecting Rod Upgrades

Available IE Connecting Rod Options:

  • H-beam 144x20 - Proven strong and reliable
  • H-beam 144x20 rifle drilled - strong and reliable with added wrist pin longevity from rifle drilling
  • Tuscan I-beam 144x20 - Our highest quality connecting rod, strong and reliable, superior strength to weight ratio, included rifle drilling for added wrist pin longevity 

Shop Engine Parts

500+ HP/TQ Piston Upgrades

  • Mahle Pistons - recommended pistons for 500HP, however there are not many bore or compression ratio options.
  • JE Pistons - a great option for street and track use, manufactured from tough 2618 alloy piston forgings. Tons of compression ratios and bore sizes available.

500+ HP/TQ Crank Damper Options

At this power level, we highly suggest using an aftermarket crankshaft damper to increase main bearing life by absorbing crankshaft vibration. We recommend the following components to fortify this interface.

  • Fluidampr crankshaft damper
  • IE/ARP crank bolt (This bolt is also reusable and does not need to be replaced) IE PN: ARP-06A-01

500+ HP/TQ Wrist Pin Upgrades

Why did we create a section just about wrist pins? We have seen endless builds fail due to under-spec’d wrist pins. Many piston manufacturers use a lighter spec pin that works for lower horsepower builds, however, with higher HP levels and raised cylinder pressures, you need a stronger wrist pin. For any build using JE pistons, we recommend upgrading to the tool steel wrist pins. Be sure to always check the material specifications and wrist pin wall thickness to avoid any pin failures!

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*NOTE - Mahle PowerPak pistons already include high quality German tool steel wrist pins. Because of this the wrist pins can easily support at least 700HP.

500+ HP/TQ Engine Bearings

We highly recommend using a performance main bearing and rod bearing as power levels increase. The main advantage of performance bearings is due to a tri-metal composition they are able to withstand added bearing loads and are better suited to withstand crankshaft flex.

  • Mahle Motorsport Main Bearings
  • Mahle Motorsport Rod BearingsStandard Thrust Bearings (OEM PN: 06A105637A)

Shop Engine Parts

500+ HP/TQ Engine Hardware

At this power level, the stock hardware is no longer sufficient. With the increased levels of load, it is very highly recommended to upgrade to ARP engine hardware. As an added bonus, ARP hardware is reusable and does not need to be replaced if removed.

In Conclusion

In this guide, we've covered everything you need to know about strengthening your VW 2.0T FSI bottom end to handle serious horsepower and torque. From understanding the fundamentals of your engine block, crankshaft, and connecting rods, to selecting the right pistons and upgrading to ARP hardware, we've provided you with the insights necessary to avoid engine block failure and achieve your performance goals.

Remember, the 2.0T FSI engine is a powerful platform with immense potential, but its stock components have their limits, especially when pushing beyond 350 HP. By carefully selecting and installing the right upgrades, you can significantly enhance your engine's reliability and longevity, even under extreme conditions.

Whether you're looking to build a street monster or a track-ready beast, Integrated Engineering offers the highest quality parts and expertise to make your project a success. Our commitment to precision engineering and performance ensures that your VW or Audi will perform at its best, mile after mile.

If you still have questions or need further guidance, don't hesitate to reach out or check out our FAQs section below. We're here to help you every step of the way.

VW 2.0T FSI Engine FAQs

What is a VW FSI Engine?

A VW FSI engine is a type of Volkswagen engine known for its direct fuel injection system. This means fuel is injected straight into the combustion chamber, allowing for precise control of the fuel-air mix. This results in better fuel efficiency and performance than older engine designs.

What Does FSI Mean in a Motor?

In a motor, FSI stands for Fuel Stratified Injection. It's a technology that delivers fuel in the most efficient way possible for both power and fuel savings. It has two modes:

  • Stratified Mode: Used when cruising or under light loads. It uses less fuel for better fuel economy.
  • Homogeneous Mode: Used when accelerating or under heavy loads. It provides a balanced fuel-air mix for maximum power.

Is an FSI Engine Good?

Yes, FSI engines are generally good. They offer a great balance of performance and fuel efficiency. The precise fuel injection leads to better combustion, meaning more power and fewer emissions.