Fabspeed sells a cold air kit that caps off the small opening in the airbox and replaces the air intake tube with a red silicone one. This supposedly increases horsepower (or not), but gives a slightly louder, deeper sound to the stock exhaust.

Well, the 997S has a flap just inside the small hole in the airbox that closes and blocks itself off at 4,000 RPM and higher. This gives the exhaust a deeper sound. You can see the flap when you remove the rubber stock air intake tube.

Can or has anyone found a way to mod this flap to keep it closed all the time, thus giving the richer stock exhaust sound all the time??? My Porsche Mechanic says This is a Holtz Resonator box to keep exhaust noise quieter at lower RPM's to pass US requirements. Thats why the flap is open at lower RPM's. He says that's all it does. So you can cap it off with a $200+ kit or find a way to mod it so it stays closed.

I know zilch about modding, but is anyone else up to the challenge???

 

Just put a plug into the rubber hose which connects to the Helmholz resonator
chamber ( I used silicone rubber mold material )

You can also disconnect the hose, cover the opening with duct tape and put the hose back over the opening .

You get that nice "throaty"sound which usually only happens at the higher RPM's all the time ( and the plug can be removed any time )
Just make sure that whatever you use is securely in there . You dont want anything to get sucked into the engine.

You do NOT get any performance change . It only affects the sound.
Btw: I don't think the resonator was put in there to comply with US noise regulations .
Have you ever been passed by a Harley ?

The noise regulations in Europe , especially Switzerland , are much more stringent. That's also the reason why the PSE is designed to function as it does ( cutout between 35 to 50 mph ) etc.

This is a cheap and effective way to get a little better ( louder) sound from the stock mufflers and it does not affect engine performance in any way .

Have fun .

 

Let me correct the above.
You do not get more sound from the mufflers( as stated above)
You get more sound from the engine air intake because it is no longer
neutralized by the Helmholz resonator.

 

Thanks guys for the alternatives. But I thought if there was a way to mod it to keep the flap closed, you wouldn't need to worry about any foreign material like a plug breaking apart and being sucked into the engine. You could just unmod it when you decided to sell and put it back to stock easily.

The flap probably works off a vacuum hose or electrical connection that you could just unplug. But being mechanically challenged, I don't know. Does anyone know how the flap is activated or if it can be disabled in the closed position???

 

I meant Thanks Rolf. Sorry I didn't realize the 2 responses were both from you Rolf.

 

Duct tape.

 

Yes duct tape will solve all issues.

 

In many cases it eliminates the need for welding!

 

Who can say "Group buy"!!!

 

I am very interested in this. I have to drive in traffic alot and I go WOT just to hear the car more which leads to a funny driving style. Is duct tape a safe solution to block the resonator?

 

theres a black hose in the engine compartment...in the back passenger side - easy to find

unplug it - your porsche dealership should have a vacuum flap to insert - its white on 1 side, black on the other...it has a a small peice of black hose on each end...insert in the open place you just created..white side up(to the left)...
presto - your exhaust is open all the time - slightly louder than normal - sounds amazing...you have no unconnected wires or any chance of a CEL

suncoast showed me how to do this..they recommended against just unplugging the orange connector

sorry if my desription isnt clear..i dont know the real term for this black and white peice - but its rubber, cant cost more than a couple dollars - they gave it to me - very easy to take in and out if you want to be able to control the exhaust again by sport button or whatever

 

Helmholtz resonator for unmarred sound
The new, individual-control Helmholtz resonator accommodated in the air filter housing is a typical feature of the acoustic refinement that has gone into the new power unit of the Carrera S. This acoustic damper offering approximately 0.3 litres of additional resonance volume is integrated in the intake system between the hot-film air mass meter and the throttle butterfly.

The Helmholtz resonator is activated when accelerating between 5000 and 6000 rpm, reducing oscillations of the intake noise under such conditions within the 260 Hertz frequency range. Porsche has already registered this new system for a patent, the new 3.8-litre power unit benefitting as a result of this technology from a deep, throaty sound under all engine loads and at all speeds, without any aggressive peaks.

 

I'm confused - is the topic PSE or Helmholz Resonator? The Fabspeed and duct tape "solutions" are for the Helmholz Resonator. I think what you're describing is a "fix" for PSE on all the time.

 

Guys, you're missing my original question. It has nothing to do with PSE or modding PSE. Not related to PSE.

There is already a flap in the resonator part of a 997S airbox that activates and closes off the resonator at 4 or 5 thousand RPM, thus giving a deeper, more throaty exhaust sound. The piece is already in the airbox. All we have to do is figure out how to deactivate it in the closed position, so the exhaust sounds deeper ALL the time. This is on stock 997S's with stock exhaust. So if we can figure out the mod, it eliminates Foam plugs, duct tape, "orange"plugs or anything else you use to plug up the resonator in the airbox. These things can deteriorate over time and may break apart, getting sucked into the air intake. The flap is already there, built into the airbox. It just needs to stay in the closed position all the time.

 

i described a fix for pse on all the time