1.8T Engine Tuning Guides
Tuning Guides
Tuning guide for 1.8T BEX engines
Full power for your Audi A4: Up to 666 hp performance!
Up to 666 hp with your A4 in four tuning stages
Here you’ll find everything you need to exploit your Audi A4’s full potential. Our tuning guide for 1.8T engines with code BEX is divided into four clearly explained tuning stages, which tell you all the necessary parts and most important tips. This is the way to a safe and long-lasting boost in performance.
Installed in:
- Audi A4
Year of manufacture:
2002 – 2004
Engine Code:
- BEX
Stage 1
increased efficiency:
+ 25 hp
+ 100 Nm
Final output:
215 hp
340 Nm
You need this extra to make it last:
Chip tuning is a lot of fun and you don't necessarily need any additional components. However, you shouldn't use longlife oil, but rather GTX Racing oil 10W-60.
BAR-TEK® TIP!
As always at this point we recommend 102 octane as fuel. This makes the engine knock less and gives you more performance. Turbo and engine should be in good condition and not too old.
To reduce coking to a minimum and keep the engine clean, we recommend installing our oil catchtank kit with TÜV.
As always at this point we recommend 102 octane as fuel. This makes the engine knock less and gives you more performance. Turbo and engine should be in good condition and not too old.
To reduce coking to a minimum and keep the engine clean, we recommend installing our oil catchtank kit with TÜV.
Stage 2
increased efficiency:
+ 50 hp
+ 120 Nm
Final output:
240 hp
360 Nm
You need this extra to make it last:
Here you should urgently upgrade to a sports clutch, as the original clutch cannot transfer this power. For the conversion to K04-01 upgrade turbocharger you should use a racing catalytic converter and our upgrade air mass meter.
BAR-TEK® TIP!
If you have already installed a sports cat, an intake hose and an upgrade charge intercooler, you can simply continue to use them. The sports cat is very important for the 1.8T engines in the Passat and Audi A4.
If you have already installed a sports cat, an intake hose and an upgrade charge intercooler, you can simply continue to use them. The sports cat is very important for the 1.8T engines in the Passat and Audi A4.
Stage 3
increased efficiency:
+ 130 hp
+ 165 Nm
Final output:
320 hp
405 Nm
You need this extra to make it last:
320 PS is a good announcement! To be able to drive this power, you should replace your connecting rods with X-beam connecting rods. Now a sports clutch kit is absolutely necessary. For the exhaust you should use a 76 mm exhaust system.
BAR-TEK® TIP!
A good software tuning of all components is required for this conversion. For this you can send your control unit to us or have your car tuned by us. Another tip from us: You should convert the downpipe to 70 mm, as the Passat and Audi A4 have a very narrow body at the bottom of the axle beam. You should move the catalytic converter downwards. This will reduce the exhaust temperature and protect the turbocharger!
A good software tuning of all components is required for this conversion. For this you can send your control unit to us or have your car tuned by us. Another tip from us: You should convert the downpipe to 70 mm, as the Passat and Audi A4 have a very narrow body at the bottom of the axle beam. You should move the catalytic converter downwards. This will reduce the exhaust temperature and protect the turbocharger!
Stage 4
increased efficiency:
+ 476 hp
+ 568 Nm
Final output:
666 hp
808 Nm
You need this extra to make it last:
We'll tell you what you need for 666 hp here shortly.
Cooling guide
increased efficiency:
Final output:
This is how you improve the cooling:
If you want to get the full performance out of your engine, you must not forget the cooling. Even a little extra power puts a lot of strain on your engine! The thermal load increases and affects all areas of your vehicle, even the transmission suffers from the new power. At best, the hard-earned power is reduced again; at worst, your engine suffers major damage. So that you can tune your engine safely and reliably, we provide you with everything you need for perfect cooling. Although it is ideal to install all parts together in a cooling bundle, you don't necessarily have to order everything at once. Each product helps you to improve cooling.
Turbo guide
increased efficiency:
Final output:
The perfect turbocharger for your tuning project
The turbocharger is one of the most important tuning measures of all, as there is huge performance potential in the compression ratio. This is why you will find all the turbos from the guides and suitable alternatives in this special turbo guide, for example if you prefer a specific manufacturer. We have also compiled a lot of information for you on the subject of turbochargers, which you should take a look at. In addition to the detailed turbo tips, there is a page on running in engines correctly, turbo lag and, of course, our 14 turbo rules.