Audi A4 B6 1.8T Stage 1/2/3 Tune (AMB)

STAGE 1: 215 HP / 250 LB-FT
STAGE 2: 235 HP / 280 LB-FT
STAGE 3: K04 AND HYBRID K04, CUSTOM CALIBRATION

Fits

Audi A4 B6 1.8T 20v, engine code AMB, 170 hp from the factory, 2002-2005. Longitudinal, wideband, and the one 1.8T in this family with a returnless fuel system, which changes what Stage 2 and Stage 3 need on the car. Pick your stage in the dropdown. The calibration is written for your car and your hardware. Not sure which code you have? Find your engine code in two minutes. The A4 B5 and Passat B5.5 with the AWM have their own listings at Stage 1 AWM and Stage 2 AWM. The earlier B5 with the AEB starts at Stage 1 AEB.

What the tune does

Written for 93 octane / 98 RON and adapts to 91 / 95. Stage 1 runs 18 psi on the stock turbo and takes a stock car from 170 hp to 215 hp and 250 lb-ft without asking anything of it. Stage 2 runs 22 psi and goes to 235 hp and 280 lb-ft once the bigger injectors are in. Stage 3 is a custom calibration built around the K04 or hybrid K04 you put on the car, 22 psi and up. All three: lag removed, speed limiter removed, rev limit raised to 7000 (7200 on Stage 3), and better mileage when you are not in it. Tested on the street and the track to be smooth yet powerful.

Stages on this listing

Start at Stage 1 if the car is stock and move up when the hardware changes. Stage 3 is for K04 and K04 hybrids only. A big turbo build needs Stage 4. Read the 1.8T 20v Tuning Guide for what each stage really gains and for the long version of the returnless fuel system.

What you need on the car

• Stage 1: nothing. Stage 1 runs on a completely stock car. A turbo-back exhaust, an upgraded diverter valve and an upgraded intercooler are all recommended, none of them are needed, and the calibration accounts for them if they are there.
• Stage 2: TT 225 injectors, 386cc. The stock 210cc injectors run out of capacity quickly on the returnless system, so this is not optional. Nothing else is required, and the same exhaust, diverter valve and intercooler are recommended. There is no 4-bar regulator on this car: the returnless system has no return line to fit one to, so the bigger injectors make up for a rail pressure that does not rise with boost.
• Stage 3 turbo: a K04 or a K04 hybrid. BBT-K04, FrankenTurbo F4 or F21, or our own GTT. Running something else? Pick Other in the Turbo dropdown and email us before you order.
• Stage 3 fueling and airflow: a TT 225 or VR6 3 inch MAF housing with the stock sensor inside, and Bosch 550cc or 630cc injectors. We sell both as plug and play sets with adapters: 550cc and 630cc. 415cc and 440cc injectors are no longer supported. Also required: turbo-back exhaust, front mount intercooler, upgraded diverter valve.
• Returnless fuel system: rail pressure on the AMB is fixed, set by the in-tank pump and a regulator that never references the manifold. It does not rise with boost, which is why this engine wants bigger injectors than any other 1.8T at the same stage. The system can be converted to return-style. The EVAP line runs from the tank to the engine bay and is the right diameter to repurpose as a return line, which lets a proper regulator go on. Worth doing before Stage 3, and do it before you order Stage 4.
• Fuel pump: the in-tank pump is a wear item on a 20-year-old car. A pump that holds pressure at idle and cruise drops off under sustained boost, and on the AMB the pump and its regulator set rail pressure on their own. Replace it before you tune.
• Plugs: run a one-step-colder plug gapped tight, NGK BKR7E or BKR7EIX at 0.028 inch. A wide gap blows the spark out under boost.
• Clutch and bottom end: a factory clutch will not hold Stage 2 torque for long. Plan on it. At Stage 3, hold torque to 300 lb-ft on a stock bottom end.

After you order

1. Order. Pick your stage and your turbo, Stock K03 for Stage 1 and Stage 2, then choose Remote Tuning. A GTS cable ships with your order for a one-time $40 and it is yours to keep for every tune after this one.
2. Read. Plug the cable into the OBD port and a Windows laptop, Windows 10 or later. An Intel Mac on Boot Camp works too. Our software identifies your ECU and saves your original calibration before anything is written.
3. Flash. We build the calibration for your car, your hardware and your fuel. You get a message the moment it is ready, and you flash it yourself in your driveway in about ten minutes.
4. Log. Drive, log, send. If anything wants adjusting we adjust it and you flash again. Stage 3 usually takes a revision or two to dial in for the exact hardware. Revisions usually come back the same day, and within 72 hours at the outside.

Prefer to mail the ECU in? Mail-in is free within the USA and Canada. We flash it on the bench and send it back in two to three days. Local? An OBD flash at the shop takes 10 to 15 minutes. How remote tuning works, start to finish.

Options explained

• Stage: pick from the table above. Stage 1 for a stock car, Stage 2 once the 386cc injectors are in, Stage 3 for a K04 or hybrid.
• Turbo: Stock K03 for Stage 1 and Stage 2. Stage 3: tell us what is on the car and the calibration is built for it. Pick Other and email us first if yours is not in the list.
• Launch control: Soft (no pops) is included free. Hard 2-step / antilag is an add-on, for off-road and competition use. Pick None if you do not want it.
• No-lift shift: included free with every GTS tune.
• Pops and bangs: exhaust crackle on lift-off.
• Hard cut: a hard fuel cut at the rev limit instead of the factory soft limiter.
• IMMO delete: removes the immobilizer check so a swapped or spare ECU runs without the key and cluster handshake.
• Mail or Remote: remote is what most owners pick. Mail-in if you would rather not touch a laptop. Dealer if a shop is doing the install for you, and we deal with them directly.