Audi A4 & A5 B9 B9.5
Home/ Shop by Make/ Audi/ A4 A5 (B9 / B9.5)
A4 / A5 B9
78 parts in stock
// Turbos all round

Audi A4 & A5 B9 B9.5

The B9 generation went turbo across the board - EA888 fours, the EA839 turbo V6 in S4/S5, and the RS4/RS5's 2.9 biturbo. All of them hide big headroom behind conservative factory maps.

Downpipes & exhaustsIntercoolersIntakesCoilovers & suspensionBrakesECU & gearbox tuningStylingWheels & spacers
ChassisB9 / B9.5
Engines2.0 TFSI 3.0 TFSI 2.9 biturbo
Production2016 - 2024
LayoutFWD / quattro
A4/A52.0 TFSI (40/45)
2016-2024 EA888 190-265hp
Stage 1 finds 50-70hp. GPF-aware exhausts needed on post-2019 cars.
S4/S53.0 TFSI (petrol) TDI
2016-2024 EA839 354hp (TDI 347)
The single-turbo V6 takes a map to ~430hp. UK cars went diesel in 2019 - also very tunable.
RS4/RS52.9 TFSI biturbo
2017-2024 450hp
Same engine family as the Porsche Panamera - Stage 1 ~530hp, Stage 2 ~600 with cooling.
0 parts for Audi A4 & A5 B9 B9.5Sort: Best-selling
No products found in this collection yet.
// Trusted on this platform
Top brands for the B9
// The platform

Conservative from the factory, mighty after software

Audi left a lot on the table with the B9. The RS4/RS5's 2.9 biturbo - an engine shared with fast Porsches - gives up 80hp to a Stage 1 map alone; the S4's EA839 V6 does similar proportionally; even the diesels find 60hp and a wall of torque. Because the ZF8 gearbox is software-limited too, gearbox tuning belongs in every B9 plan. Hardware is mature: downpipes, cooling and intakes from the usual VAG heavyweights.

The proven upgrade path

01
Stage 1
Engine map + ZF8 gearbox tune together - the B9 transforms with software alone.
02
Stage 2
Downpipes, intercooler and intake with a matched map - ~600hp RS4/RS5s on stock turbos.
03
Cooling
Charge cooling and oil temps limit repeat performance - upgrade before chasing more boost.
04
Chassis
Coilovers and geometry; spacers and wheels wake the styling up as much as the handling.
// In-house ECU tuning
In-house ECU tuning for the 2.9 TFSI, EA839 & EA888
Stage 1-3 and custom mapping for the 2.9 TFSI, EA839 & EA888, all done in-house - the map to match the hardware above.
Explore ECU tuning →

B9 - frequently asked

How much does a Stage 1 RS4/RS5 make?

Around 520-540hp on pump fuel, with the factory hardware untouched - the 2.9 biturbo is heavily de-rated from the factory. Stage 2 with downpipes and cooling approaches 600.

Is the TDI S4/S5 worth tuning?

Yes - the 347hp V6 TDI picks up roughly 60hp and 100lb-ft from software, and the electric compressor keeps response sharp. GPF/AdBlue systems stay in place.

Do I need a gearbox tune?

Strongly recommended on any tuned B9 - the ZF8's factory torque limiter otherwise clips what the engine map delivers, and shift speed improves noticeably.

Do you offer ECU tuning in-house?

Yes - Stage 1-3 and custom ECU mapping are done fully in-house. We don't currently offer parts fitting, but we're happy to advise on your install.

// Browse the range

B9 parts by category