#How to remove the particulate filters GPF - OPF in the gasoline engine

How to remove the particulate filters GPF - OPF in the gasoline engine

Seletron Performance

GPF- OPF delete with Seletron XPF tuning units


Exhaust systems in internal combustion engines and related fluid dynamics are two topics we have already covered in some depth in a previous article. Of course, we have certainly not exhausted these topics as they are very complex and intricate; moreover, the fluid dynamics of the exhaust system combine with that of the internal combustion engine and also indirectly with electronic management. Hence, fully understanding what happens to exhaust gases and the engine itself is not simple. In the previous article, however, we explained some essential basics and also gave some examples that can help shed light on these fluid dynamics and their influence on engine performance. At the bottom of this article, we will include the link to the previous news story that talks about this but now let's not lose the focus and go back to our XPF tuning unit for remove GPF - OPF.


The issue is certainly not new; as early as the early 1990s, the first requests to remove the catalytic converter on cars with gasoline, turbocharged, or naturally aspirated engines emerged. In fact, from the beginning, the catalytic converter created a sort of "plug" on the exhaust system, thus penalizing (usually) delivery at higher engine speeds. This means that the catalytic converter has always "stolen" some horsepower from aspirated engines of regular cars and some extra horsepower on turbo-petrol engines. This has led to the need for some people to remove it to "free" the exhaust from this excessive backpressure at maximum engine loads that, to some extent, compromises its maximum power and torque at medium-high engine speeds.


In the 1990s, the modification was quite widespread in the world of automotive tuning, both on regular 1600- 1800- 2000cc naturally aspirated engines and on the turbochargers in vogue in those years. Suffice it to mention the benchmarks of the time, such as the Lancia Delta Integrale HF turbo, the Opel Calibra turbo 16V, the Ford Escort RS Cosworth, and the Alfa Romeo 155 Q4, the legends of those years, all with 2-liter displacement, 4 valves per cylinder, turbocharging via a single scroll turbocharger, air-to-air intercooler, and power outputs ranging from 190hp (155 Q4) to 220hp (Escort RS Cosworth). Already on these cars, removing the catalytic converter provided improved mid- and high-rpm delivery with increased power generation. The price to be paid, however, was usually a torque "draining" at low revs, a phenomenon that can be partly nullified by using special catalytic converters (100-cell, 200-cell) or perforated tubes that allow better gas passage without compromising performance too much at lower revs.


In the previous article, we briefly touched on this issue, and we invite you to read it if you are interested in the topic. Today, however, we want to focus on the electronic aspect involving the removal of systems such as catalytic converters, particulate filters on petrol engines (GPF - OPF).

By now, we all know that for many years, all modern common-rail turbodiesels have had systems to trap the particulate matter generated during the diesel combustion phase. On gasoline engines, however, this is more recent and originated with the advent of engines with direct gasoline injection systems, which are becoming increasingly popular today. AUDI was one of the first manufacturers to bring attractive turbo-petrol engines to market with this more effective and precise injection system. Mercedes and BMW have also gone down this road, and in fact, a great many models on the road today have supercharged engines with direct gasoline injection, some quick examples? Many AUDI models with the TFSI acronym (e.g., A4 2.0TFSI 211hp or 254hp), Mercedes C-Class, and GLC 250 with the 2-liter turbo 16V 211hp or 300 engine with the same architecture and power outputs of 245hp or 258hp. BMW offers many models called Twin Power Turbos with a direct gasoline injection system, as do various other manufacturers.


Even on the recent models just mentioned, the removal of the particulate filter and catalytic converter yields major performance benefits; some tuners have measured power gains of as much as 15 to 20 hp just by removing the OPF – GPF system. The only technical problem (and here we get into the focus of this article) is that the ECU engine control unit immediately, or almost immediately, notices the lack of these devices in the exhaust system. How can it tell? It detects it through the sensors (digital or analog) that measure the pressure differential at the inlet and outlet of the particulate filter, exactly as has been the case on turbodiesels for many years now. The problem then is that when the particulate filter is removed, the ECU notices and goes into recovery, thereby cutting power. In some cases, remapping the ECU can solve this problem (although this has some considerable drawbacks that we have already talked about, namely the difficulty or impossibility of restoring the original mapping without leaving indelible traces). In other, more recent cases, remapping the engine ECU is not possible because, on some models, an automatic update occurs that resets the manufacturer-imposed maps.


How can you emulate the presence of catalytic converters and particulate filters on turbodiesel and turbo-petrol engines? Again, SELETRON has found a neat, effective solution that leaves no indelible traces while still providing the ability to restore everything to stock conditions without violating the original engine control unit. In fact, SELETRON has developed a special chip tuning unit that can simulate the presence of particulate filters by acting on the sensor signals (analog or digital) that detect pressure (backpressure) values in the exhaust system. This new series of chip tuning additional units were not created for direct engine enhancement but to allow the removal of filtering devices by emulating their presence and preventing the ECU engine control unit from going haywire.


Installing Seletron XPF tuning unitfor GPF – OPF delete, enables the customization of the exhaust system according to the customer's needs without problems arising from ECU resetting. Of course, the Seletron XPF tuning unit for GPF - OPF, and catalytic converter emulation can also be installed alongside the CHIPBOX chip tuning module for increased power and torque. The advantages that can be obtained by freely intervening on the exhaust system are as follows:


Increased power and torque

Increased thrust at higher engine speeds

Improved engine response at higher engine speeds

Reduction in gasoline or diesel fuel consumption

Reduced temperatures on the hot side of the turbocharger


Request more information about the availability of the Seletron XPF tuning unit for gasoline catalytic converter and particulate filter emulation!


If you want to read the article where we previously discussed exhaust systems and their fluid dynamics in internal combustion (and diesel) engines, click here https://seletron.com/en/news/107_dpf-fap-cat-remove