
The basic reason for forced induction (turbo or supercharger) is not to increase compression or the maximum pressure in an engine cylinder, it is to increase volumetric efficiency (the efficiency of the engine at drawing in air) although forced induction is the most effective method of upping compression.
In computer games we just tick a box, and within seconds our car is fully turbocharged and running much faster. In the real world things are very different.
Particulate filters and FAP Performance gains.
The particulate filter is a stand alone unit. It is located upstream of the cat in the exhaust system and its purpose is to remove soot particles from the gas stream. The cat the proceeds to do its usual job of converting CO to CO2 and is in no way dependent or relied upon by the particulate filter.
In diesels the cats are two way devices and run in unregulated mode (ie. no O2 sensor like a petrol car).
Boost controllers and remaps
Boost controllers
The turbo is driven by the exhaust gases and the faster the exhaust flows the quicker the turbo spins and more air gets forced in to the engine.
If too much air is forced into the engine then it will run lean. This causes an intermittent loss of power and you also risk putting too much pressure on the engine with a surge of power.
Vents – adding performance with Bonnet vents.
Performance gains are possible with the addition of bonnet vents.
Warm air really does kill performance. This is due to the air intake temperatures being hot and air at high temperatures carries less oxygen.
When driving an engine hard the under bonnet temperatures quickly build up and the engine has no choice but to suck this air in reducing your power.