Air Filter Noise
Discussion
In order to solve a load of troulble, I have fitted a breather air filter to the idle air valve/controller on my Modular Ford V8. This is in place of the pipe leading back to the air intake.
The only problem is that the air flow through this little foam filter is very noisy at idle. There is serious roar.
Any thoughts on the easiest way to make it quieter
The only problem is that the air flow through this little foam filter is very noisy at idle. There is serious roar.
Any thoughts on the easiest way to make it quieter
If it's the same sort of problem as the monstrous induction roar you get from fitting cone filters in the engine bay, the only real way round it is how the OEM airboxes work - enclosing the airstream so the resonant noise isn't transmitted to the engine bay and hence the cabin, or changing the resonant frequency to a lower (inaudible) note. You may have to build an airbox around it and ducting to a fresh air source (though if it's just the idle control air intake then it won't need loads of air, and the temperature of the air won't be as much of an issue as it is for the performance of the 'main' air intake).
The Ford V8 in my MG ZT came with a ridiculous 'snorkel' from the plenum and filter that snaked its way down to the bottom front of the engine bay - very restrictive for breathing (probably why the motor only gave 260 bhp from 4.6 litres) but those who removed this for a simple cone reported no real performance gain (very hot in there so the gain from the increased flow was negated by the fact it drew in hot air) and a LOT more noise. I've got a honking great supercharger on mine which makes its own noise...
The Ford V8 in my MG ZT came with a ridiculous 'snorkel' from the plenum and filter that snaked its way down to the bottom front of the engine bay - very restrictive for breathing (probably why the motor only gave 260 bhp from 4.6 litres) but those who removed this for a simple cone reported no real performance gain (very hot in there so the gain from the increased flow was negated by the fact it drew in hot air) and a LOT more noise. I've got a honking great supercharger on mine which makes its own noise...
A Vortech supercharger was the main reason for fitting the filter.
Origionally the IAC was supplied with air from the intake just in front of the supercharger. Everytime the IAC made an adjustment to the air flow, the supercharger would speed up or slow down, changing the pressure of the air supplied to the IAC. It's a vicious circle!
Idle is great now and stalling is a thing of the past. Just got to sort out the noise.
Has anyone seen any enclosures that might do the job?
Origionally the IAC was supplied with air from the intake just in front of the supercharger. Everytime the IAC made an adjustment to the air flow, the supercharger would speed up or slow down, changing the pressure of the air supplied to the IAC. It's a vicious circle!
Idle is great now and stalling is a thing of the past. Just got to sort out the noise.
Has anyone seen any enclosures that might do the job?
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