Handcrafted exhaustsystem with valve flaps for Ferrari 355

The exhaust is handcrafted of 1.4828 stainless steel exceptionel in Germany on order and contains 2 valve flaps. Controlling the flaps is done with our control unit.

This system fixes the known problems with the original F355 OEM system.
The problem begins once the exhaust gas valve opens. Once the exhaust gas valve opens, the exhaust gases do not flow through the main catalytic converter but completely through the bypass. The exhaust gases flow off the exit which leads to the main catalytic converter and generate there a vacuum. Thus the hot exhaust gases being in the muffler are aspirated backwards through the main CAT which additionally heat up the gases. Then the gases are guided though the bypass and radiated by the exhaust gas valve into the muffler again. When the exhaust gas valve is open, this gas flow is circulating ceaselessly generating more and more heat. We are of the opinion that this problem is known to Ferrari. For this reason the F360 was changed since 1996 from engine 2.7 to 5.2 and the manifolds were modified exactly in the place where the vacuum is generated. But the problem was not eliminated by this measure.
Now you can imagine that an extreme back pressure is generating in a case when the complete exhaust gases coming from the engine and those which are aspirated backwards have to flow through 1 exhaust gas valve. That’s the reason why the F355 does not provide the power as indicated.

So it was obvious for us that our theory was right and that the bypass causes this problem and that 1 exhaust gas valve is not sufficient and thus leading to extensive heat due to the back pressure. Our exhaust systems, irrespective of the racing or the usual model, are so designed that the ways from the main catalytic converter to the outer end pipes guide and those from the bypass to the inner end pipes. These ways do not lead to each other. Consequently it is not possible when the vacuum in the main cat is generated that hot exhaust gases are aspirated but it aspirated cold air through the outer end pipe backwards through the catalytic converter and the bypass and the valve. Once cold air is mixed up with hot exhaust gases, the temperature of the exhaust gases is decreasing and also the temperature of the complete system.

We expressly point out that this exhaust system comes without the approval of the German TÜV authority. For this reason it is not allowed to use this exhaust on public roads in Germany and also partly not allowed in some other countries. Please observe the legal requirements in the respective country.

In case of installing the sports catalytic converter, it may happen under some circumstances that the check engine light is triggered.