1.8T TUNING INFORMATION AND TUNING GUIDE
Here’s a collection of information about the 1.8t engines i have collected and use myself over the years, I hope you find it helpful.
A brief history of the 1.8t engine –
The 1.8t engine was developed by Audi and first appeared on our roads in 1996 fitted to the Audi A4 1.8t in 150hp form, since then its been used across all VAG brands in multiple vehicles types which can be seen further down the page.
What you might be interested to hear is its use in motorsport such as formula palmer Audi which was an open wheel race series which the engines output was boosted to 300 hp and 360 hp with over boost ( push to pass ) function with the help of a garret T34 turbo.
The 1.8t engine was also used in formula 2 in 2009 -10 which the engines output was boosted to 425hp and 480hp with the use of an over boost function, this was with a fully built race engine and Garret GT35 turbocharger.
1.8t engine block types 06a and 058
The 058 block has an intermediate shaft which drives the oil pump and external water pump driven by an aux belt, This block was only fitted to early B5 VW Passat and Audi A4
The 06a block has an internal water pump driven by the cam belt and the oil pump is chain driven from the crankshaft, The block is fitted to pretty much all 1.8t models after the later part of the year 2000.
Where is your engine code ?
The engine code can be found on the corner of the cylinder head on the cam belt end, on the engine block itself near the cylinder in between cylinders 3 +4 or could be found in your service book.
Is my engine small or large port ? Here’s a list of popular 1.8t engine codes
Small port engine codes –
BEA, AWT, ARX, ARZ, AWC, BJX ,BAM, APX, AMK, BVR, AJQ, AJL, APP, BBU, APY, AUQ, BEX, AYP, AVJ, ADR, AMB, AMU, APT, APU, ARG, ATC, ATW, AWM, AWP
Large port engine codes –
AGU, AJH, AEB, AJL,
1.8t ECU types
The 1.8t came with two models of ECU from Bosch the M3.8.3 and Bosch ME7.5
The M3.8.3 was fitted to the earlier 1.8t models ( upto around 2000 ) and easily identified by the cable operated throttle body and this was also a narrowband lambda ECU.
The Bosch ME7.5 was fitted to the later 1.8t models with an electronic throttle also known as ( ETB ) or ( fly by wire ) and this version came with both narrowband and wideband lambda control again usually earlier models upto 2001 had narrowband.
What is the difference between Narrowband and Wideband lambda ?
A narrow band lambda sensor is an oxygen sensor that is only knows when the mixture is Rich, stoic, and lean. The sensor only works in a narrow band of voltage 0 – 1v hence its name so can only report to the ECU for example a lean condition so it switches to go richer and vise versa.
A wideband o2 sensor is much better at reporting the air fuel ratio due to it operating in a much wider band of voltage ( 0 – 5v ) and each voltage reading is correlated to an actual air fuel ratio so therefore is actually reading the live AFR and reporting it to the ECU to make instant changes to target an actual value. This makes the wideband lambda a far better tuning tool.
1.8T ENGINE TORQUE SPECS / SETTINGS << Check this page out for 1.8t torque specs