I know there's a simple mod to the 997.1 airbox that bypasses the Helmholtz regulator, which improves the intake sound. Is there something like that for the 997.2?

 

Pyres make sure your air box has the aramid screen instead of the plain plastic covers.

 

The addition of aftermarket (K&N, BMC) air filters may add a little intake noise over the stock paper filters.

 

No way to permanently block off the Helmholtz chamber?

 

Today I tried driving without the air box cover. I am using BMC filters.
There is a nice sound increase. very noticable from inside.
Top end screams nice, and even at low revs you hear the intake sound.

Factory lower box keep heat rise from the filters.
And the air inlets still bring air cool air to the filters.

Not a power gain thing, its more for sound.

Simple 8 screws to get off or back on.

 

You are going to put back on the cover right?

 

Was planning to try it open for a few days.
Why? Do you foresee a problem?

 

There is some hot engine bay air entering the airbox now that the top cover and snorkels have been removed. Sound has been gained but power is being lost. How much lost power is debatable. Honestly you probably wouldn't notice unless driving on the track or driving on a really hot day.

Dry weather driving is fine. Wet weather driving or washing the car can get the filters wet degrading airflow. Too wet and water can get sucked into the intake and possibly the engine.

 

^^^ That's why I was asking,exactly what semicycler stated!

 

I wouldn't worry about water ingestion unless the filter is completely submerged or water is actively being sprayed on the filters with a hose or something while the engine is running. Thousands of 911 owners run around every day with aftermarket intake with open filter elements without hydrolocking.

 

The main reason for saying no on running it like this is the fact that there isn't an Air Dam around the filters to protect from the warm air entering and or large amounts of water being sucked into the filters when you take the stock filter covers off to get a nice sound!Yes, it take's larger amounts of water to cause damage (hydrolocking)and short sprays of water into the throttle body can blast carbon off in the combustion chambers and pistons domes...anymore than that your asking for serious $$$ engine issues and will be so detrimental to an engine!!! Bottom line keep an air filter cover on! (the choice is yours)...and how it was designed in the first place! IMHO!!!

 

Porsche covered it for a reason. To keep hot air out. End of story

 

I found the intake sound I was seeking by adding the BMC Filter, GT3 Throttle Body & GT3 Plenum. Intake sound and increased throttle response. Very easy mod; I did myself, start to finish 2 hours in my garage.

 

Does replacing the OEM filter with a BMC make that big of a difference?

 

Gasongasoff- I noticed a bit more intake sound, not increase or decrease on fuel mileage, but who is counting. Some people claim a better peddle response at low rpm's I however couldn't say that I did. It's nice be be able to clean and replace the filter instead of buying a new one. I'm sure the car breaths better. Hope that helps.