The 3.0 Diesel N57 Engine found in most of the F Series (and some of the E Series) BMWs is highly tuneable, and pretty much bullet proof (save for the usually emissions gremlins).
We have tuned many of them over the years, and now have a good recipe for the ultimate daily driver setup whilst maintaining that reliability.
This Blog Post is specifically talking about the N57N / N57D30A engine with Solenoid Injectors, but the principles of the mods are pretty similar to the other N57 Engines.

Tuning

Custom dyno tuning starts from £450 + VAT
This is a fully custom tune that's specific to your vehicle which includes road testing, logging and dyno testing with before and after printouts. We would expect ~300-320bhp

For models with Automatic Gearboxes, we can also offer tuning for that. The F Series engines have a 8HP Gearbox.
Details of our services are linked below:

Intercoolers

OE Intercoolers on BMW's prove to be a limiting factor when tuning, IAT's are often in excess of 60°, with our intercooler upgrade on the F30s installed, we saw a maximum of 35° on the dyno. We have several upgrades depending on your platform.

Emissions

We also have EGR, Swirl Flap and DPF removal options. If everything is healthy, we do not generally see an increase in power with these mods, but it does help with reliability as you are removing a potential failure point.

Downpipes

The DPF can be removed to maximise exhaust gas flow which in turn allows faster spool and lower exhaust gas temperatures. The ECU is less likely to pull power due to DPF protection.
We must advise it is illegal to remove emission control devices from vehicles permitted to drive on UK roads.
The work would be strictly performed for off road use. This means we can not accept any responsibility for the vehicle being driven on UK roads.

Turbochargers

If you are not happy with the power from the Stock Turbo, we have a couple of Hybrid options. The GTD2872VR fits exactly like stock, with the Outlet Damper, so will look pretty factory to the untrained eye. If you do not need to retain that, then you can go with the GTD2873VR. The 72mm will max out ~420bhp and the 73mm will max out ~440bhp.

Fuel System

As a quick easy fix is the Metering Valve (Straight Plug), which will allow the stock pump to maintain rail pressure at higher RPMs. Above this, we would need to look at a Fuel Pump Upgrade.
We also recommend a Rail Pressure sensor upgrade, as the stock 2200 BAR Sensor cannot read high enough.
We would expect to see around 375-385bhp & 550ft/lbs with the above upgrades
Next would be the HPFP and Injectors. Fitting just the injectors, additional to the above upgrades would see an extra 10-15bhp (395-405bhp) but more noticeably, 60ft/lbs of torque (610ft/lbs)!
Next is the HPFP (High Pressure Fuel Pump). This saw a ~25bhp gain but again more impressively, nearly 100ft/lbs of torque over just the injectors (700ft/lbs).

Air Flow

To maximise the upgrades we can currently offer, the final step are the Race Cams. These provided enough extra torque to break the 1000NM barrier! With these installed the final figures were 454.7bhp & 750ft/lbs (1016nm).

Please see below for a video a customer vehicle we did this conversion on: