Chipping diesels

What the hell is a common rail??! This has always confused me - enlighten me please someone!

The good - improved torque, improved performance, can lead to reduced fuel consumption (if you drive normally).

The bad - invalidates any engine warranty*, can lead to increased fuel consumption (if you use the additional performance), costs a few hundred quid.

Common rail high pressure injection systems? None.

A few Google searches. Van Aaken Motorsport, or Superchips, perhaps.

The message from "Ben Organ" contains these words:

Old diesels had a pump rather like a petrol engined car's ditributor. Fuel was sent along individual pipes to each cylinder at the appropriate time.

Modern "common rail" diesels have a single high pressure fuel rail common to all the injectors, which are then fired electronically [1] to tap into this rail to inject the fuel.

The advantages are that since the dead space between the high pressure circuit at the point of injection is short the timing and amount of fuel can be more easily modulated to give better economy or power or emmisions....pick any two.

What car are you considering? The pros and cons are similar to any tuning though additional black smoke is an additional worry if the fuel is simply tuned up.

They're in a higher state of tune already, TDi VAG engines that run a 5 speed box are near the torque limit of the g'box...

Sell the car, buy a more pokey version. Avoid chips on the basis that swopping an EEprom for 400+ quid is taking the *&^& in my book... ;-)

JH

Older diesels have a pump, a bit like a distributor, that sends high pressure fuel of a measured amount individually to each cylinder via a passive injector.

A common rail system has a high pressure constant feed to all the injectors which are actively controlled from a central ECU etc to give the correct fuelling.

Ish.

Cheers!