PSE baffle/raspy resonance at 2850 rpm/Dension Install
05-14-2013, 07:04 PM
#1
PSE baffle/raspy resonance at 2850 rpm/Dension Install
Hello Ladies and Gents,
I have been living with my 997.1 S for a couple of months now as a daily driver, and I've noticed a couple of peculiarities.
I notice that when I have the sport mode engaged, and the sport exhaust is "re-plumbed," the volume and characteristic of the exhaust note is not consistent through out the rev range. It's as if the "baffle" or shut-off valve is shutting off at certain RPM's. Or, is this a characteristic of the PSE. The exhaust is much louder and burbly at idle and throughout most of the rev range, but gets noticeably quiet at certain RPMs in any gear. Is this normal?
Second observation. Has anybody noticed a rather metallic/raspy resonance at about 2850 rpm in this vehicle, as if something is vibrating only at this rpm? It is very rpm specific. It's hard to describe in words, but it's audibly different than any other rpm. All engines seem to have an rpm where they sound better or worse, but I just thought I would ask. It's not a good sounding noise.
To say I went through the ringer and back with regards to the Dension install is an understatement. Long story short, my July '05 built 2006 Aero does not have a digital amplifier, much like that of a GT3 I'm told. Since there were no other digital devices in the factory MOST loop, we simply disconnected the factory loop and connected the Dension directly to the PCM and vice versa, creating our own loop. It took The Porsche techs some time to educate the PCM what to be looking for, and the direction it should be looking, but we got it to work. What a buggy product, though! Forget about using the USB drive as you would an ipod, with separate playlists/folders. The USB interface is very bad. The ipod interface is rather good, so I relented and dedicated an ipod to the car (which I was hoping to avoid in favor of a USB-based music source). I feel like I'm an expert in Dension installations now (I installed my unit) so if anybody has any questions or particularly if you've hit a brick wall, please contact me. Having said all of this, Eric at Bumper Plugs was amazing, as he is known to be on these forums. Dension USA and Dension Europe were also helpful. Ultimately, we all learned something about these cars and the variations that exist. At the end of the day, I still get the "Can't find the CD changer" warning screen when first turning the PCM on, but you simply enter through that once. No big deal, again, just a little bit buggy.
I read the new posts with my cappuccino each morning and have learned much about these magnificent machines. Thanks for that.
Frank
I have been living with my 997.1 S for a couple of months now as a daily driver, and I've noticed a couple of peculiarities.
I notice that when I have the sport mode engaged, and the sport exhaust is "re-plumbed," the volume and characteristic of the exhaust note is not consistent through out the rev range. It's as if the "baffle" or shut-off valve is shutting off at certain RPM's. Or, is this a characteristic of the PSE. The exhaust is much louder and burbly at idle and throughout most of the rev range, but gets noticeably quiet at certain RPMs in any gear. Is this normal?
Second observation. Has anybody noticed a rather metallic/raspy resonance at about 2850 rpm in this vehicle, as if something is vibrating only at this rpm? It is very rpm specific. It's hard to describe in words, but it's audibly different than any other rpm. All engines seem to have an rpm where they sound better or worse, but I just thought I would ask. It's not a good sounding noise.
To say I went through the ringer and back with regards to the Dension install is an understatement. Long story short, my July '05 built 2006 Aero does not have a digital amplifier, much like that of a GT3 I'm told. Since there were no other digital devices in the factory MOST loop, we simply disconnected the factory loop and connected the Dension directly to the PCM and vice versa, creating our own loop. It took The Porsche techs some time to educate the PCM what to be looking for, and the direction it should be looking, but we got it to work. What a buggy product, though! Forget about using the USB drive as you would an ipod, with separate playlists/folders. The USB interface is very bad. The ipod interface is rather good, so I relented and dedicated an ipod to the car (which I was hoping to avoid in favor of a USB-based music source). I feel like I'm an expert in Dension installations now (I installed my unit) so if anybody has any questions or particularly if you've hit a brick wall, please contact me. Having said all of this, Eric at Bumper Plugs was amazing, as he is known to be on these forums. Dension USA and Dension Europe were also helpful. Ultimately, we all learned something about these cars and the variations that exist. At the end of the day, I still get the "Can't find the CD changer" warning screen when first turning the PCM on, but you simply enter through that once. No big deal, again, just a little bit buggy.
I read the new posts with my cappuccino each morning and have learned much about these magnificent machines. Thanks for that.
Frank
05-14-2013, 08:20 PM
#2
Rennlist Member
Not sure if it is what you are experiencing since you notice it going quiet at the same RPM range regardless of speed, gear, etc. but I understand that the DME on these cars quiets the PSE from 25-40 MPH apparently.
I just had the a full factory install of the PSE on my 997.2 car and this weekend I hope to investigate if it quiets down from 25-40 MPH or not.
I just had the a full factory install of the PSE on my 997.2 car and this weekend I hope to investigate if it quiets down from 25-40 MPH or not.
05-14-2013, 11:29 PM
#3
Hello Ladies and Gents,
Second observation. Has anybody noticed a rather metallic/raspy resonance at about 2850 rpm in this vehicle, as if something is vibrating only at this rpm? It is very rpm specific. It's hard to describe in words, but it's audibly different than any other rpm. All engines seem to have an rpm where they sound better or worse, but I just thought I would ask. It's not a good sounding noise.
Frank
Second observation. Has anybody noticed a rather metallic/raspy resonance at about 2850 rpm in this vehicle, as if something is vibrating only at this rpm? It is very rpm specific. It's hard to describe in words, but it's audibly different than any other rpm. All engines seem to have an rpm where they sound better or worse, but I just thought I would ask. It's not a good sounding noise.
Frank
05-16-2013, 04:35 PM
#4
Intermediate
Join Date: Dec 2012
Posts: 34
Likes: 0
Received 0 Likes
on
0 Posts
Here is some more information, very interesting stuff.
https://rennlist.com/forums/997-foru...resonator.html
I did the cap mod to bypass the resonator, it makes a difference in those ranges.
https://rennlist.com/forums/997-foru...resonator.html
I did the cap mod to bypass the resonator, it makes a difference in those ranges.
05-22-2013, 08:06 AM
#5
I confirmed that the baffle effect or muting of the PSE while in sport mode is NOT rpm specific. Rather, when revving/accelerating briskly, the PSE gets silent in the 3k range. However, if I engine brake/decelerate just a bit at the same rpm it goes silent, then accelerate again, the PSE is back on. It's as if some engine vacuum is effecting the baffle's operation (opening and closing).
