There are alot of generic and bespoke remaps, digital tuning boxes and analogue resistor devices to choose from these days , and to a certain extent I imagine one gets what one pays for most of the time. However, unless you are going to change engine mechnicals, the only way (as I see it) to achieve more power/torque is to alter the injector fuelling on the basis that the standard engine is actually detuned to allow good running with a variety of poorer diesel fuels. Therefore can anyone tell me why a cheap (

To me, just as you say you will get what you pay for.

Bad Points.

Increased fuel consumption,

More black smoke,

After a short while the ECU will throw the Check engine light as it will think something is wrong with the sensor. This will need a visit to the dealer to remove.

A better solution is a proper remap, this adjusts not only the fueling, but ignition timing, and turbo boost pressure to get more from the engine. If you were to go for a custom remap, the tuner could map the engine how you wanted. eg, less power low down the rev range, but more from mid to high rpm. Most remaps will also improve the MPG, because if you drive with the same driving style as now the engine will not need to work as hard.

A remap doesnt fool anything. It changes the parameters within the ECU for fueling and boost and when they occur.

A tuning box makes the ECU think that the fuel is colder than it is to overfuel it. This is all well and good but what you have done is lost part of that sensors scope and it is now not working as it should.

On a car with a propper remap then all the sensors are stil doing thier job, just with re aligned values.

Bad Points.

Increased fuel consumption' date='

More black smoke,

After a short while the ECU will throw the Check engine light as it will think something is wrong with the sensor. This will need a visit to the dealer to remove.

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Funnily enough, I didn't get any of those during the 20k miles I ran one on my Fabia PD100 Best bang-for-buck mod I did and it even sailed through the MOT with it on too.

Chris

IIRC there is a difference between 'just a resistor' and an analogue tuning box, the analogue ones tend to be stepped in at least 3 stages, digital ones are stepped in many more (sufficiently so to make it less likely to show errors). The big plus point of a tuning box is that it does not impact on the boost pressure and thus doesn't impact on the turbo's durability, whereas a remap tends to tweak about with boost (generally increase).

A remap is the most refined way of getting more power etc though

It also depends on the value of the resistor. Go too high and you'll see the check engine light, but this happens with Dragon boxes too.