29-05-2012, 09:44 AM
The Helmholtz resonator is another form of pulse tuning, it's like blowing across the top of a bottle, air is being drawn in past the resonator space, but then when the air is removed, it sucks more in to fill it's space, but there's obviously inertia when air moves, taking air with it, more than is required causing more air to be entered into the engine - obviously this has to be tuned to a specific RPM/frequency to gain most effect...
Technically, yes, the management could be confused by the removal of the resonator, since it's probably tuned for midrange torque, you'll probably find the engine overfuels very slightly midrange...
The biggest problem with the GTi6 manifold is actually on changing throttle IMO - especially when in closed loop, since the ECU only uses the throttle position for changing transients (i.e. during opening throttle or during closing throttle), that's when it'll get confused, thinking about it more, it's probably quite happy with the MAP readings - it may be slightly out of calibration, but when it goes to adjust for transients, that's when it'll get confused, the airflow in and out of the engine is so drastically changed - whether it's quicker or slower, I don't know, I'm going to guess that the air moves faster, meaning the management responds too slowly to what's actually going on...
There's evidently something that causes this weird running and it's GOT to be to do with the manifold change, I'm struggling for reasons also as to why, but something causes it...
Technically, yes, the management could be confused by the removal of the resonator, since it's probably tuned for midrange torque, you'll probably find the engine overfuels very slightly midrange...
The biggest problem with the GTi6 manifold is actually on changing throttle IMO - especially when in closed loop, since the ECU only uses the throttle position for changing transients (i.e. during opening throttle or during closing throttle), that's when it'll get confused, thinking about it more, it's probably quite happy with the MAP readings - it may be slightly out of calibration, but when it goes to adjust for transients, that's when it'll get confused, the airflow in and out of the engine is so drastically changed - whether it's quicker or slower, I don't know, I'm going to guess that the air moves faster, meaning the management responds too slowly to what's actually going on...
There's evidently something that causes this weird running and it's GOT to be to do with the manifold change, I'm struggling for reasons also as to why, but something causes it...
