Originally Posted by dj_alarm
What's the purpose of the cone?
The cone forms part of the tuned intake system. Basically when the engine sucks in air it creates a negative pressure wave, this travels down the intake and gets reflected back down to the intake by the cone. This reflected pressure wave helps in filling of the cylinders.
The reason it is cone shaped is so that different parts of the cone reflect pressure waves at different RPM.
Its a bit like a tuned exhaust system, only in reverse, the pressure wave in an exhaust assist in emptying the cylinders.
I would leave it in. I tried my 156 with it removed and the car lost torque.
Fiat Coupe 20VT, mildly tuned to 260bhp
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