Luxury and performance combined. This BMW 730d — the N57 straight-six diesel — came in for our full engine and gearbox package: a custom Stage 1 dyno calibration paired with xHP Stage 3 gearbox software, developed live on our 4WD linked V-Tech dyno.
It arrived producing 249bhp and 552Nm on our baseline run. After the Stage 1 calibration and xHP Stage 3, it left making 325bhp and 708Nm — measured on the rollers, not estimated:
| Measurement | Stock | DC Stage 1 + xHP ST3 |
|---|---|---|
| Engine power | 249.6 hp @ 4,091rpm | 325.6 hp @ 4,077rpm |
| Engine torque | 552 Nm @ 2,193rpm | 708 Nm @ 2,299rpm |
| Wheel power | 205.8 hp @ 3,292rpm | 285.2 hp @ 3,573rpm |
That’s +76bhp and +156Nm. The aim was to enhance real-world performance while preserving the refinement you expect from a 7 Series. The result is a much stronger mid-range, smoother yet sharper throttle response and effortless acceleration — the car feels significantly lighter on its feet despite its size.
The xHP Stage 3 gearbox tuning plays a key role in the transformation. On the ZF8 automatic it delivers quicker, more decisive shifts, improved shift logic under load and far better torque management — the whole driving experience is sharper and more responsive, yet still exceptionally smooth.
All calibration work was carried out in-house on our 4WD linked V-Tech dyno, with a full health check before any tuning and live data logging throughout. The map was written for this exact car — its ECU variant, its fuel, its condition. No generic files. No shortcuts. Just precision N57 tuning done properly, with the original software backed up so it’s fully reversible.
730d, 740d or another 3.0-litre straight-six — we can transform how it drives while keeping that 7 Series refinement. See our BMW 30d tuning page for figures, check your car’s gains, or get a free quote and we’ll book you in.
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Specialist BMW & VAG tuning, dyno-proven in Warrington. Tell us your car and we’ll send your gains and pricing.
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