Your Vehicle
Jaguar XJ 4.2 V8 SC 400hp
Technical Specifications
Power and torque increase
Stage 1: software remap only, no mechanical changes, fully reversible.
Stage 1: file 100 € online + installation 350 € at the workshop (via the OBD port) Book now
Power HP
Torque Nm
Buy the Stage 1 file, pay the installation at the workshop
100 € VAT included: the file developed for your engine, paid online
Installation: 350 € network price, the workshop may charge less, paid at the chosen workshop (via the OBD port) · terms
Power Graph
Jaguar XJ 4.2 V8 SC 400hp: da 400 a 470HP
Remapping Jaguar XJ
MasterTuning develops remapping for Jaguar. La Jaguar XJ 4.2 V8 SC 400hp può passare da 400 HP a 470 HP con un incremento di 70 HP.
The development of each remap is customized by MasterTuning.
- 100% customised files with lifetime warranty
- Reference values for Stage 1: the file is developed on your vehicle and checked in the workshop
- Best performance, within safety margins
- Reduced fuel consumption
ECU Remapping Details Jaguar XJ 4.2 V8 SC 400hp
The Jaguar XJ 4.2 V8 SC 400hp is equipped with a petrol engine that produces 400 HP and 540 Nm of torque in its factory configuration. With MasterTuning's professional ECU remapping, this Jaguar can achieve 470 HP (+18%) and 630 Nm (+17%).
Our Stage 1 tuning for the XJ 2003 - 2009 delivers an impressive gain of +70 HP and +90 Nm, optimizing the petrol engine's performance while maintaining reliability and staying within safe parameters.
The engine code AJ34 identifies this specific powerplant configuration. The Denso MB279700 ECU is professionally recalibrated to unlock hidden potential while preserving engine longevity.
With 400 HP from factory, this Jaguar XJ is already a performance vehicle. Our remapping extracts even more potential, delivering exhilarating acceleration and enhanced driving dynamics for enthusiasts who demand the best.
Technical Specifications — Jaguar XJ 4.2 V8 SC 400hp
Factory technical data for the Jaguar XJ 4.2 V8 SC 400hp (2003 - 2009), used by MasterTuning engineers to develop a remap tailored to this specific powerplant. Figures shown are reference values for Stage 1; the file is developed on your vehicle and checked in the workshop.
| Engine code | AJ34 |
|---|---|
| ECU / Control unit | Denso MB279700 |
| Fuel | Petrol |
| Compression ratio | 9.1 |
| Bore × stroke | 86.0 X 90.3 mm |
| Stock power | 400 HP · 540 Nm |
| Remapped power (Stage 1) | 470 HP (+70) · 630 Nm (+90) |
Don't want to touch the ECU?
Rapid Dimsport add-on modules connect to the engine sensors with original connectors: they fit in a few hours and come off without a trace, leaving the factory software untouched. Useful on a leased car, one still under warranty or one you plan to sell soon. Check which ones fit your Jaguar XJ.
Frequently Asked Questions - Jaguar XJ
How much power can I gain from remapping my Jaguar XJ?
With MasterTuning Stage 1, your Jaguar XJ 4.2 V8 SC 400hp can gain +70 HP (from 400 to 470 HP) and +90 Nm of torque. This represents a 18% increase in power.
Is ECU remapping safe for the Jaguar XJ engine?
Yes, MasterTuning's remapping for the Jaguar XJ 4.2 V8 SC 400hp is developed within safe parameters. Each file is developed on your vehicle, checked in the workshop and stays within the mechanical limits of the AJ34 engine.
Is the Jaguar ECU remapping reversible?
Absolutely. The original factory calibration of your Jaguar XJ is always backed up before remapping. The process is 100% reversible at any time.
Will remapping affect my Jaguar warranty?
ECU remapping may affect your manufacturer warranty. We recommend checking your specific warranty terms. Many of our customers choose to remap after the warranty period or accept this trade-off for the significant performance gains.
Other Remaps You Might Like
Other Engines Jaguar XJ 2003 - 2009
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Book your remap or ask for a quote
Stage 1 can be bought online and is done at the workshop you choose; for Stage 2 we send you a quote.
Stage 2 is quoted on request: write to us and we will reply with price and timing.
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