Some people might think that this is an aggressive approach, but I can't care less as it seems that some so called professionals are not quite as professional and make statements just to pretend being in the know, which I find rather annoying. With this thread I intend to take the mystery out of the performance tuning and show up the arguments of rogue traders. Performance tuning is not a miracle, but hard work and precision engineering. It is based on physical principles that can be used or abused. To get the most out of the combustion the objective is to get as much air in as possible, the right amount of fuel, the correct ignition timing as well as the fastest possible flame front development. To achieve the best result all 4 aspects need looking at separately. At the same time all four aspects have to be brought in line. To master this correctly is the art a professional performance tuner is a master of. Just plonking in a tuning box is not professional tuning. Nor is the adding up of different performance items professional. One of the tuning boxes promoted here show some fundumental flaws on the petrol turbos. They might gain power, but lose power in some Fiat applications towards the red line, which means that they can be lethal when extremely hard driven. Tuning boxes are popular in India due to the lack of chassis dynos. However, they are not the way forward. Adding a free flow filter is in very few cases an advantage. The term free flow filter is basically meaningless. A correctly designed air intake revision is something completely different. An AIR is developed to achieve a task based on mathematical calculations and not just something that flows better. The reason for the misconception is that air intakes do not have a constant flow, but a pulsing flow. This creates for the designer some problems but also opportunities. Claiming that an certain air filter brand is always helping as as valuable as for a hungry person knowing that bananas are curved. Of course a filter design can help flow, but the filter does not make an air intake revision. There is much more to it. AIRs can be tuned for power as well as torque. To get the best out of both worlds the designer has to resort to a combination of ideas. When done correctly the results are astonishing. Adding on a FFE can be as much hit and miss as a randomly fitted AIR. Primary pipes, secondary pipes and collector pipes are in a mathematical relation. One of the parameters can be chosen, which is the peak power point, but the remaining parameters fall into place after calculation. The term FFE is therefore about as misleading as the terms free flow air filter. To make matters worse AIRs and FFEs are in a relation too. All these changes require specific ECU maps. A tuning box will not show the results with some preset values. A dedicated re-map is absolutely necessary to get the optimal results. Anything else is bodging. There is many more aspects to cover, but the main point is to bring some transparency into the subject and further questions can be answered as we go along.