1.8 Turbo 20V

1.8 Turbo 20V

Information on the Volkswagen / Audi 1.8 Turbo 20V engine

Front Wheel Drive transverse mounted



All Wheel Drive longitudinally mounted






General Information

Cylinders
4
Displacement
1781 cc / 108.7 ci
Firing Order
1,3,4,2

Stock engine handles around 400 wheel horsepower and around 7200rpm before issues. Head bolts, exhaust valves, valve springs and retainers will then need attention.
Stock rods handle up to 300lbft
Stock engine and trans mounts 250lbft


CAN

This vehicles uses CAN bus for various devices throughout the vehicle. This can include the dashboard, ABS, and Body Control. 
These vehicles are supported by the Elite 1500 and 2500 models.





Model Variants

There are at least 45 variants of this engine!  Far too many to go into detail on each an every variant, so the key technologies present on them are what will be covered.

Some models have a cable/psuedo DBW throttle system.  
Some have narrow band O2 sensors, some have a 4.2 Wideband pre-cat sensor.
Some have switched VVT on the inlet cam
Some are transverse Front Wheel or All Wheel Drive
Some are longitudinal Front Wheel or All Wheel Drive
Various turbochargers have been used throughout the years. Some extremely small, some much larger supporting more power. Either K03 or K04.
Various injector flow rates have been used
There are a number of different head designs. All are 20V but some use small and some use large ports.
Some Audi A4 models use twin intercoolers, one in front of each front wheel.








Sensor Information

Crank/Cam Sensor

This engines uses a Crank Position Sensor and a Cam Position Sensor.  The crank trigger has a 60x tooth wheel with 2x missing teeth (60-2).  The cam trigger has 4x teeth with 2x larger and 2x small teeth. The ECU expects to see a different number of cam trigger teeth between each crank trigger missing tooth event.  i.e. in one crank revolution, from the missing tooth event ocuring until the next time the ECU sees the missing teeth event we should see 1x cam tooth event.  In the next crank revolution we should see 3x cam trigger teeth.  This counting of the cam trigger teeth tells the ECU which cycle the engine is on but all timing itself is done by only the crank trigger, as for all missing tooth crank trigger systems.


Crank Trigger Wheel



Cam Trigger Wheel






Crank Sensor

A Reluctor crank position sensor is used.  This is located near the oil filter towards the front of the engine.  There are two different sensor variants, both are reluctor but have different pinouts.

To verify which sensor type you have you will need to do a resistance check on pins 1 and 2.  If there is no resistance you have the first type listed below. If there is resistance you have the second type.

Reluctor Wiring AUQ/AUM/BAM
Pin
Description
Haltech Connection (Trigger 4-core)
1
Shield Ground
Haltech Trigger Shield
2
Reluctor -
Green
3
Reluctor +
Yellow

Reluctor Wiring AEB/APU
Pin
Description
Haltech Connection (Trigger 4-core)
1
Reluctor +
Yellow
2
Reluctor -
Green
3
Shield Ground
Haltech Trigger Shield






Cam Sensor

A Hall Effect cam sensor is used. This is located on the cam timing belt end of the cylinder head.

Hall Effect Wiring
Pin
Description
Haltech Connection (Home 4-core)
1
12V+ Switched
Red
2
Signal (Home +)
Yellow
3
Signal Ground
Blue





Trigger Configuration



   











Ignition Coils and Igniter

The ignition coils on this engine require an external igniter module.  The vehicles fitted with this engine come with a 4x channel igniter module. if no igniter module is present the Haltech HPI4 igniter can be used.  The Haltech Quad Channel OEM Igniter has the same wiring as the VW OEM igniter module.

Ignition Coils


Pin
Description
1
Signal From Igniter
2
Ground (to cylinder head)
3
12V+ Switched




Igniter Module






Haltech HPI Igniter

A Haltech HPI 4 igniter is recommended for this application.
    

See the Haltech HPI Quick Start Guide for wiring information on these igniters.


Dwell Time

The dwell time shown below is taken from our 1.8 Turbo base map









DBW Throttle System

This engine uses two different Drive By Wire throttle body systems. 

Early models have a cable throttle but use a DBW style system to act as moving throttle stop. This provides idle and cruise control to the throttle body but a cable is used to open the throttle from there.  If a throttle cable is present then this is the type of system being used. This type of throttle is not currently supported by Haltech. 




Later models use a normal DBW throttle body and do not have a throttle cable.  This is supported by Haltech.




DBW Throttle Wiring


Position Sensors
Pin
Description
Haltech Connection
1
TPS2AVI 3
2
5V+5V+
4
TPS1
AVI 2
6Signal Ground
Signal Ground

Drive Motor
Pin
Haltech Connection
3
DBW1
5DBW2



DBW Accelerator Pedal Position Sensors Connection



Pin
Description
Haltech Connection
1
5V+5V
2
5V+5V
3
Signal GroundSignal Ground
4
APP Signal 2AVI 5
5
Signal GroundSignal Ground
6
APP Signal 1AVI 4





MAP Sensor

These engines do not come with a MAP sensor.  They do have a Baro sensor but this cannot be used for tuning.
Use the internal MAP sensor that comes with your ECU.  For higher boost levels an external MAP sensor should be used instead, connected to a spare AVI.









Variable Cams

Some variants of this engine have a switched on/off variable intake cam system.








Idle Valve

All variants use the DBW throttle body for idle control. Engines equiped with a cable throttle body have a motor controlled throttle stop that acts in a similar way to DBW, moving the throttle blade to achieve idle control.






Coolant Temperature

These engines come with a 4-pin Coolant Temperature Sensor
 
Pin
Function
Haltech Connection
1
Signal Ground
Signal Ground (Black/White)
2
Gauge Sender Ground
---
3
ECU Signal
Spare AVI (AVI 8)
4
Gauge Sender Signal
---
An AVI with a selectable Pullup should be used.  If not and external 1k pullup to 5V should be connected.







Air Temp

An inlet air temperature sensor is located in the inlet plenum.
  

Wiring is not polarity sensitive.
Pin
Haltech Connection
1
Any Spare AVI*
2
Signal Ground
An AVI with a selectable Pullup should be used.  If not and external 1k pullup to 5V should be connected.







Knock Sensor

These engines come with 2x knock sensors.  Both can be used with an Elite 2500, however only 1x knock sensor can be used with an Elite 1500.

Pin
Haltech Connection
1
Knock Signal
2
Shield
3
Signal Ground






MAF Sensor

Although most users of Haltech ECUs will be deleting the MAF, it is possible to use a MAF if you prefer.



Pin
Description
Haltech Connection
1
Engine Ground
---
2
Sensor Ground
Sensor Ground
3
12V+ Switched
---
4
Signal 0-5V (AVI)
Any Spare AVI








O2 Sensors

Early models have narrow band sensors for pre and post catalytic converter.  Later models have a Bosch 4.2 Wideband Sensor.  At this point the 4.2 sensor cannot be used and should be swapped for a Haltech WB1

For correct operation a Haltech WB1 kit is highly recommended for this application, with the provided 4.9 sensors replacing the pre-cat sensors.  Sensors use a 22mm socket or spanner to remove and replace.








Vehicle Speed Sensor

This engine uses a Hall Effect Vehicle Speed sensor.



Hall Effect Speed Sensor
Pin
Description
Haltech Connection
112V+ Switched
---
2Signal
Spare SPI or DPI
3GroundSensor Ground






Injector Data

Flow

The injector flow rate is measured with the injectors held wide open at 100% duty.  For fuel systems with a fixed regulator pressure (often returnless systems) that is not referenced to manifold pressure the flow needs to be mapped over Manifold Pressure for accurate tuning.

There are numerous injector flow rates that have been used on the 1.8 Turbo engine.

Most models: 282cc/min
Some models: 317cc/min however these appear to be rated at 4bar pressure instead of 3bar, so they may be the same as 280cc
Some Passat Models: 210cc/min
Audi TT Quattro/225/Audi S3: 386cc/min


Dead Time

When an injector is commanded to open for a certain amount of time, the dead time is the amount of time the injector is not actually open during this period.  It covers the time to energise the solenoid and begin to open and the time to close as well.  There are also transient periods during which the injector is opening and closing where fuel flow is not at full capacity so this lost peak flow period is also taken into account.  

From the Haltech Base Map:











OEM ECU Information


   

Location

Golf 4: ECU is located under the windscreen wiper trim panel.






ECU Pinout


   






Base Maps


Base maps have been created for use with the Haltech Elite Adapter Harnesses and come included with the ESP Software package

To use these maps they should be IMPORTED into your ECU.  Follow the IMPORTING A BASE MAP guide.




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