Opel Astra J and K: Turbo Petrols and CDTI Diesels Examined

The Astra J (2009–2015) and the Astra K (from 2015) are the compacts Opel has on the road in large numbers: as five-door, Sports Tourer and, in the Astra J's case, also as GTC and OPC. For tuning the choice is wide: small turbo petrols, a genuine performance engine in the OPC and several diesels of very different origin. Headroom, access method and price vary accordingly.

Astra J: the petrol engines

Our catalog lists these turbo petrols for the Astra J:

Engine	Engine code	Output (catalog)	ECU
1.4 Turbo	A14NEL / A14NET	120 / 140 hp	Delco E78
1.6 Turbo	A16XHT	170 hp	Delco E39A
1.6 Turbo VVT	A16LET	180 hp	Delco E83
OPC 2.0 Turbo	A20NHH	280 hp	Delco E39A

The Delco E39, E78 and E83 ECUs belong to GM's "Global A" platform. For forced-induction engines in this family, our data gives a typical 15–30% more power and 20–30% more torque as a Stage 1 guide value. On the 1.4 Turbo the effect is most obvious in everyday driving: the small engine pulls noticeably earlier and harder, especially in a loaded Sports Tourer.

The OPC is a slightly different story. The engine is already highly stressed from the factory, so a power increase has to be carefully matched to fuel quality, charge-air temperature and the clutch. Stage 2 with hardware is possible on the turbo versions of this family, but requires a healthy clutch and an exhaust with catalyst and certification.

The naturally aspirated 1.4 and 1.6 in the Astra J gain very little, by contrast. Our data gives only around 3–8% for naturally aspirated engines.

Astra J: the diesels

The diesels show how international Opel's engine line-up was:

Engine	Output (catalog)	ECU	Origin
1.3 CDTI (A13DTE)	90 hp	Bosch EDC17C19	Fiat cooperation
1.7 CDTI (A17DTJ/DTR)	110 / 125 hp	Denso	Isuzu
1.7 CDTI ecoFlex (A17DTC/DTE/DTF/DTN)	101–130 hp	Delco E87	Isuzu
2.0 CDTI	depends on version	Bosch EDC17C18/C19/C59	GM

1.7 CDTI: Depending on the version, the Isuzu diesel comes with a Denso or a Delco ECU. For the Delco E87 (assigned to the Delphi DCM family in our data) we give a typical 20–30% as a guide value, for the Denso version a typical 15–25% power and 20–30% torque. Tool coverage is patchier on Denso ECUs, so we check readability in advance.

2.0 CDTI: The two-litre with a Bosch EDC17 offers a typical 20–30% as a guide value. Depending on the software version, the ECU has to be opened for writing.

1.3 CDTI: On the small diesel with EDC17C19, a typical 20–30% is also realistic, though on a 90 hp engine that naturally remains modest in absolute terms.

Astra K: how we proceed

We do not currently list the Astra K as a separate model range in our catalog. That does not mean it cannot be done. It means we check the ECU, software version and access method before making an offer. The Astra K engines are more modern designs with stricter emission standards and newer ECUs; blanket statements about gains would not be serious here. Through the configurator you can send an enquiry with engine and model year, and we will get back to you with a concrete assessment.

Options

For the petrol family of the Delco ECUs, the following are documented alongside Stage 1, among others:

• Sharp Throttle and Vmax removal (mind tyres and registration)
• Rev limiter increase
• DTC Off only for non-emissions-related fault codes
• Launch Control and No-Lift Shift on the turbo versions, on request depending on software version

Functions such as the hardcut limiter, pops & bangs or the popcorn limiter can partly be implemented on these ECUs, but are intended exclusively for motorsport on closed tracks, not for public roads. On the diesels, the focus is on ECO tuning, Sharp Throttle, Vmax and DTC Off.

Before tuning

On a turbo petrol, ignition and charge-air path matter: worn spark plugs and leaking hoses eat any extra power. On a diesel, the focus is on the particulate filter, EGR and dual-mass flywheel. Disabling the DPF or EGR is emissions tampering and illegal on public roads. A clean software works with the aftertreatment, not against it.

Process and prices

We work on Opel directly at the ECU: on site in Stödtlen at an appointment of your choice or by sending in the ECU. The price is the same, and booking is online.

Under our pricing rules, the Astra J 1.4 Turbo with 140 hp and the Astra J OPC with 280 hp start from €170 for Stage 1. The Astra J 1.7 CDTI ecoFlex with 130 hp (Delco E87) starts at €300, and the Astra J 2.0 CDTI comes to €350 including opening the ECU.

On the legal side: the software change voids the type approval. The software is intended for motorsport use only, see the motorsport notice.

Common questions from the workshop

1.4 Turbo with 120 or 140 hp: is it the same engine? The A14NEL with 120 hp and the A14NET with 140 hp belong to the same engine family and use the same Delco ECU. The differences lie largely in software. That is exactly why the weaker version in particular responds clearly to a calibration.

Isn't the Astra OPC already at its limit? The OPC is highly stressed from the factory, but not at its mechanical end. A moderate Stage 1 is possible but requires good conditions: high-octane fuel, a healthy clutch, a leak-free charge-air path and an ignition system in good condition. If you drive it on track, also keep an eye on charge-air temperature.

Why is the 1.7 CDTI cheaper than the 2.0 CDTI? Our price is based on the ECU generation and access method. The 1.7 CDTI runs older Denso or Delco units, the 2.0 CDTI a Bosch EDC17 whose housing often has to be opened for boot access. That is more work and therefore more expensive, regardless of how much power comes out at the end.

Conclusion

The Astra J is a treasure trove for sensible tuning: the turbo petrols with Delco ECUs respond with a typical 15–30% as a guide value, the diesels with 15–30% depending on origin and ECU. On the Astra K we assess each case individually instead of promising figures. Sort out ignition, charge air and aftertreatment before your appointment and you will get the most out of your Astra. More on the Opel diesel in our article on the Insignia 2.0 CDTI and in the glossary under CDTI.