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I disconnected mine almost a year ago. Found some caps that fit both ends where I disconnected the tubes and glued them in with hi-temp RTV. Also stuffed some foam in the tube leading to the cabinet from both ends, engine and cabin side. No adverse effects. The hardest part was finding the right size caps to plug the tubes.
Imagine installing them with some hi density foam in the tube... Drone gone!
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Originally Posted by aft86
Yes, there is only one tube going into the cabin on the driver's side. Also, I feel like we shouldn't be taping anything on these cars. Working on a plug to click in there.
I recently plugged both ends of my symposer tube on my 2019 TTS. It definitely helps reduce the drone we're all talking about. Mine is not entirely gone but much better. I'm guessing my tube plugging could be better and I'd be super interested in buying a solid rubber plug, if anyone decides to do a run.
As to why Porsche does it? On normally aspirated engines there is an induction noise which comes from the air intake which can be quite mellifluous. This is different and distinct from the exhaust sound and really enhances the overall sound of the engine, especially at full throttle.
Because the turbos muffle this noise, Porsche runs a tube from the intake area into the cabin to try to recreate this sound. And it does do that. My car is noticeably quieter with the symposer plugged, when at full throttle. But this tube also magnifies the drone, which a significant number of owners don't like, myself included.
My car is noticeably quieter with the symposer plugged, when at full throttle. But this tube also magnifies the drone, which a significant number of owners don't like, myself included.
Yes, the difference is subtle but very noticeable. The car also feels more solid and compact overall, besides being quieter in the cabin.
I am testing different resins and foams for fitment and sound dampening. Will get back with an update soon, hopefully. These take forever to mold and test.
Yes, the difference is subtle but very noticeable. The car also feels more solid and compact overall, besides being quieter in the cabin.
I am testing different resins and foams for fitment and sound dampening. Will get back with an update soon, hopefully. These take forever to mold and test.
Thanks for making the effort! I will gladly wait for a great solution over just adequate...
The main reason I went with the Turbo was to enjoy a quieter - ultra high performance GT style vehicle. After all, 911 Turbo's are now heavier and dimensionally larger than Porsches greatest Grand Touring car (the 928) ever was. There are sooooo many varieties of 911 offered, one of them should be quiet enough for long road trips and offer a business environment where phone calls are comfortable. IMO the "Symposer" represents the Turbo trying to be too many things to too many people.
It also makes me wonder again about Porsches model naming rationale. Should there be a "Turbo GT" for those of us that want prodigious power and handling in a stealthy "coupe" package? I'll never understand why Porsche uses GT 2 & 3 to name cars that are anything but Grand Tourers... Surely they jest... Don't get me started on Taycan...
The main reason I went with the Turbo was to enjoy a quieter - ultra high performance GT style vehicle. There are sooooo many varieties of 911 offered, one of them should be quiet enough for long road trips and offer a business environment where phone calls are comfortable. IMO the "Symposer" represents the Turbo trying to be too many things to too many people.
Enjoy!
Agree 100%. From a driving perspective, this car does everything I was hoping for with just one single fault and that is the cabin noise, including but not limited to the droning and the road noise. There are so many well engineered aspects to this car that the noise topic just baffles me.
Update:
The test mule is holding up well. This week (weather permitting) I will test out silicone in the plug chamber. I haven't seen much a of a different with the materials (soft foam, weather insulation, rubber, etc.) I've put into the plug as far as sound dampening.
Have a 991.2 Turbo 2017 and plugged the hole in the rear deck with Noico 80 mil 10 sqft car Sound deadening mat -- available from Amazon. In addition I applied this material to the panel behind the insulation in the rear deck (inside) just in front of the engine. The result was less than satisfactory as it muffled the sound minimally, but the drone got worse -- more like a booming sound, and the clicking (higher pitch) of the gears switching (the good sound) is gone. I'm going to remove the material from the hole. The sound is louder in Sports Mode, than normal mode, but the performance suffers in Normal Mode, plus the engine stops and starts unless you push the "A" button in this mode. The sound is more pronounced when the engine is under load -- going up grades.
I tried plugging it, etc. I ended up giving and going in the opposite direction as it didn’t improve the drone enough —I installed a sharkwerks exhaust which changed the overall sound. The overall droning is much less and at a different rpm that ends up being less of an issue for me. Plus the car is still quiet when in normal mode and taking it easy. Otherwise it has a more exciting growl.
I tried plugging it, etc. I ended up giving and going in the opposite direction as it didnt improve the drone enough I installed a sharkwerks exhaust which changed the overall sound. The overall droning is much less and at a different rpm that ends up being less of an issue for me. Plus the car is still quiet when in normal mode and taking it easy. Otherwise it has a more exciting growl.
02-19-2019, 12:44 PM
