on video VAG 1.8T 20V - What makes it GREAT

 What is up engine heads, it’s time for another episode of iconic engines. It’s been a while hasn’t it. Well today we’re back with a European giant. And no, it’s not a giant engine, at only 1.8 liters and 4 cylinders it’s one the smaller end of the scale, but it’s a giant in the sense of the incredibly important role it has played and continues to play in the European, Brazilian, UK and a few other non-US tuning and aftermarket modification scenes. The VAG 1.8t 20V may have graced the engine bay of what many consider to be the most disappointing Volkswagen Golf GTI ever, but it’s accessibility, ease of tuning and power potential meant that it quickly became the best sleeper GTI ever

Now Volkswagen is an interesting brand. And if you’re coming over from a Japanese or American manufacturer you’re used to clearly defined lines. In a sense most automakers employ what’s similar to a caste system for their engine families. In other words there’s no mixing between the families. 

Compared to this the Volkswagen group four cylinder world is one big orgy and drawing clearly defined lines between the engines is difficult and inevitably ends up being subjective. 

The reason is that the grandfather of all vw water cooled inline fours is actually a Mercedes engine called the M118 which was Mercedes' attempt to take Auto Union into a new direction, away from DKW's two stroke smokiness. Of course all of this was happening back when Mercedes owned Auto Union (today Audi) and sent over a man called Ludwig Kraus to build a future for Audi. But before any of it actually bore fruit Mercedes sold Audi to Volkswagen who saw it as a great opportunity to pick up much needed expertise in a time of declining sales for the air-colled VW Beetle that finally started showing it's age. But when Audi went to VW, Ludwig Kraus didn't, Mercedes' prominent engineer stayed over at VW and started working into redesigning the M118 into something new. The new engine was called the EA111 and saw the light of day in 1974, first in the Audi 50 and then in the first ever Volkswagen Polo. 

Now our engine of interest the 1.8 turbo 20 valve bears both the EA827 and EA113 code because it's production spawned both generations. The 1.8t 20v engine saw the light of day in 1993 on the Audi A4 and it received a very lukewarm reception, largely due to it's 150hp output. Soon after it would grace the engine bay of the Golf MK4 GTI, again with only 150hp, representing what many saw as a shame to the GTI name. In the years that followed VAG would install the 1.8t 20v into virtually everything it had on offer with four valves. A total of 16 cars got this engine and this list includes everything, from the tiny Polo and Ibiza to the Leon, Octavia and even the hefty Audi A6 and Skoda Superb. Power outputs soon started growing to and the ubiquitous 1.8 eventually covered a range from 150 to 240 horsepower. 

But by far it's most significant achievement has been achieved after its warranty....in the tuning scene. The incredibly widespread nature of this engine meant that for many the 1.8t as their first turbo car. The tuning scene would soon change forever and Volkswagen's initially disappointing little four cylinder would almost single-handed breed an entire generation of power addicts.

Now the 1.8t engine may pale in comparison to more exotic powerplants but it's blessed with simple, robust and proven hardware which is often the most reliable path towards pragmatic, real life fun and enjoyment. 

We have a bore of 81mm and a stroke of 86.4mm, giving us a pretty undersquare design, which by it's nature results in good amounts of torque low in the rev range.

Most engines feature an aluminum intake manifold and cast log type exhaust manifolds. There are three different KKK turbochargers fitted to the engines and they are K03, K03S and K04. Most engines feature the basic K03, while the K03s can be found on the following engines and the K04 being reserved for the most powerful versions. 

K03S turbos are on: BBU, BE, BJX, BVP, ARY, AUQ, AWV, ARX, AUM, AWP, BEX 

K04 turbos are on: BFV, APY, APX, AMK, BAM

Everything else like the AEB, AGU and others is K03 turbo. 

The tuning success comes from the fact that the VW 1.8t 20v ticks all the right boxes. It's plentiful and readily available and not too expensive which means replacement and upgrade parts can easily be sourced. The engine is already turbocharged from the factory, the internals aren't weak and the ECU isn't restrictive or impossible to remap. So you can easily score +40hp on the 150 engines with zero hardware changes and zero getting dirty.

 What is up engine heads, it’s time for another episode of iconic engines. It’s been a while hasn’t it. Well today we’re back with a European giant. And no, it’s not a giant engine, at only 1.8 liters and 4 cylinders it’s one the smaller end of the scale, but it’s a giant in the sense of the incredibly important role it has played and continues to play in the European, Brazilian, UK and a few other non-US tuning and aftermarket modification scenes. The VAG 1.8t 20V may have graced the engine bay of what many consider to be the most disappointing Volkswagen Golf GTI ever, but it’s accessibility, ease of tuning and power potential meant that it quickly became the best sleeper GTI ever

Now Volkswagen is an interesting brand. And if you’re coming over from a Japanese or American manufacturer you’re used to clearly defined lines. In a sense most automakers employ what’s similar to a caste system for their engine families. In other words there’s no mixing between the families. 

Compared to this the Volkswagen group four cylinder world is one big orgy and drawing clearly defined lines between the engines is difficult and inevitably ends up being subjective. 

The reason is that the grandfather of all vw water cooled inline fours is actually a Mercedes engine called the M118 which was Mercedes' attempt to take Auto Union into a new direction, away from DKW's two stroke smokiness. Of course all of this was happening back when Mercedes owned Auto Union (today Audi) and sent over a man called Ludwig Kraus to build a future for Audi. But before any of it actually bore fruit Mercedes sold Audi to Volkswagen who saw it as a great opportunity to pick up much needed expertise in a time of declining sales for the air-colled VW Beetle that finally started showing it's age. But when Audi went to VW, Ludwig Kraus didn't, Mercedes' prominent engineer stayed over at VW and started working into redesigning the M118 into something new. The new engine was called the EA111 and saw the light of day in 1974, first in the Audi 50 and then in the first ever Volkswagen Polo. 

Now our engine of interest the 1.8 turbo 20 valve bears both the EA827 and EA113 code because it's production spawned both generations. The 1.8t 20v engine saw the light of day in 1993 on the Audi A4 and it received a very lukewarm reception, largely due to it's 150hp output. Soon after it would grace the engine bay of the Golf MK4 GTI, again with only 150hp, representing what many saw as a shame to the GTI name. In the years that followed VAG would install the 1.8t 20v into virtually everything it had on offer with four valves. A total of 16 cars got this engine and this list includes everything, from the tiny Polo and Ibiza to the Leon, Octavia and even the hefty Audi A6 and Skoda Superb. Power outputs soon started growing to and the ubiquitous 1.8 eventually covered a range from 150 to 240 horsepower. 

But by far it's most significant achievement has been achieved after its warranty....in the tuning scene. The incredibly widespread nature of this engine meant that for many the 1.8t as their first turbo car. The tuning scene would soon change forever and Volkswagen's initially disappointing little four cylinder would almost single-handed breed an entire generation of power addicts.

Now the 1.8t engine may pale in comparison to more exotic powerplants but it's blessed with simple, robust and proven hardware which is often the most reliable path towards pragmatic, real life fun and enjoyment. 

We have a bore of 81mm and a stroke of 86.4mm, giving us a pretty undersquare design, which by it's nature results in good amounts of torque low in the rev range.

Most engines feature an aluminum intake manifold and cast log type exhaust manifolds. There are three different KKK turbochargers fitted to the engines and they are K03, K03S and K04. Most engines feature the basic K03, while the K03s can be found on the following engines and the K04 being reserved for the most powerful versions. 

K03S turbos are on: BBU, BE, BJX, BVP, ARY, AUQ, AWV, ARX, AUM, AWP, BEX 

K04 turbos are on: BFV, APY, APX, AMK, BAM

Everything else like the AEB, AGU and others is K03 turbo. 

The tuning success comes from the fact that the VW 1.8t 20v ticks all the right boxes. It's plentiful and readily available and not too expensive which means replacement and upgrade parts can easily be sourced. The engine is already turbocharged from the factory, the internals aren't weak and the ECU isn't restrictive or impossible to remap. So you can easily score +40hp on the 150 engines with zero hardware changes and zero getting dirty.