創業の1972年以来、Giannelli（ジェネリ）は一貫してよりモーターバイク用のより良いデザインと機能の ギゾーストシステム生産に携わってきました。Giannelli（ジェネリ）マフラーは、創業者のフリオ・ジェネリ氏と ジョージオ・ジェネリ氏のサーキットレースでの経験と、技術的により優れ斬新なデザインのマフラーを作り出すという 情熱から生まれて来ました。
Giannelli（ジェネリ）はイタリアで走行規格に合致した製品を作り出した最初のメーカーです。 さらにはヨーロッパの厳格なe3規格も取得しています。 今日ではGiannelli（ジェネリ）は世界40ヵ国で販売されています。
Just like a human being, a motor breathes. On one side of the cylinder a valve opens and takes in a fuel mixture that explodes once it’s inside. After combustion, another valve lets out the gasses, just like our mouth exhales air after it has been used by our lungs (fig. A).
A motor devours a tremendous quantity of air, therefore it needs a healthy breathing system. The parameters that determine the breathing of a motors are form, length and width of its exhaust system. Changing these parameters, one can optimise the way a motor breathes, and thus the way it performs.
As the pressure wave reaches the end of the pipe, an emptiness awaits: the outside world, with a pressure infinitely lower than the pressure on the inside of the pipe. Shocked by this emptiness, the pressure wave bounces back inside, transforming itself from pressure into depression (which is nothing but pressure travelling back in the opposite direction). Back at the exhalation valve where it started its journey, the pressure wave bounces once more, and shoots towards the end of the pipe again (fig. B).
The pressure wave, ricocheting back and forth between cylinder and exhaust exit, shoots through the much slower gas column as the latter travels towards the end of the pipe.
Every time the two meet while the pressure wave is travelling back towards the cylinder, the pressure compresses the gasses. Instead, every time they meet while travelling in the same direction (towards the end of the pipe), the gas column is dissipated by the pressure wave.
This way, the pressure wave shooting back and forth through the gas column transforms the latter into a sort of accordion that expands and compresses continuously (fig. C and D).
At Giannelli’s Research & Development Department, a new exhaust system is tested extensively. Every exhaust is fitted on the bike it is meant for, it is tested, modified, tested again, shortened, extended, and tested again, until it makes the motor breathe and perform like we want it to.
In fact, at Giannelli Silencers, a new exhaust system is never born on a designers table: it is born among welding sparks and the bangs of hammers beating steel. Here at Giannelli, an exhaust system is brought into the world by the oil-stained hands of our engineers.