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Message: Exhaust noises
Changed By: jakeru
Change Date: April 25, 2015 12:25AM
Exhaust noises
Change Date: April 25, 2015 12:25AM
Exhaust noises
Hey folks,
I wanted to talk exhaust noises.
My 2001 2.7 Boxster I just got came with these after market mufflers:
[img]http://s22.postimg.org/4udd0rky9/image/v2ohq551p/
.jpg[/img]
Although they sound amazing at higher engine speeds, they are pretty loud and "droney" at lower engine speed when under load. Not having the benefit of having tried a stock muffler, I'm not quite certain what to expect, but I think it could be a lot quieter.
Does anyone else have a similar exhaust setup, and how is it compared to alternatives?
In researching muffler design on these cars, it seems the ones reported to have less drone (including the stock muffler) have a crossover element in the muffler that connects the left and right cylinder banks. I happen to have a tig welding setup here, and was thinking about fabricating a crossover pipe that basically would link the two muffler outlets together in perhaps a straight line. The idea is some of the sound pulse energy will reverberate into the opposing cylinder bank's muffler. (The pulses alternate between cylinder banks, so I think this will dampen the low order exhaust harmonic). I could tune it for lots of dampening (big straight crossover pipe) or little bit of dampening (smaller diameter crossover pipe, fitted further back towards the exhaust tips). I'm not sure if you guys can visualize this based on my description, but what do you think?
The other exhaust noise I want to get feedback about fixing is what I believe to be a rattling catalytic converter. It seems to only really rattle when it's hot. Metallic rattling like a loose heat shield (but I checked and tried to tighten those, but the problem persisted). It seems louder on the right/passenger side - especially with passenger window rolled down when driving near an object on that side (like a wall or in a parking garage).. I read about one guy here having noisy catalytic converters which he fixed by replacing them outright, but he had some other problems (like low power I think, and bad emissions results), and his car also had roughly double the miles mine (which is "only"110k miles. :) ). Has anyone else here had a fixed rattling catalytic converter somehow other than replacing it outright? Anyone know what exactly is making it rattle as it comes up to temperature?
Finally, is it ok to jack where I have indicatpictured below? Someone at a local porsche shop said they do it there all the time, but I got realizing it was supporting the entire weight of the rear half of the car through the two transmission mounts.
[img]http://s22.postimg.org/82hudt781/image/707nv9oel/
Thanks.jpg[/img]
I wanted to talk exhaust noises.
My 2001 2.7 Boxster I just got came with these after market mufflers:
[img]http://s22.postimg.org/4udd0rky9/image/v2ohq551p/
.jpg[/img]
Although they sound amazing at higher engine speeds, they are pretty loud and "droney" at lower engine speed when under load. Not having the benefit of having tried a stock muffler, I'm not quite certain what to expect, but I think it could be a lot quieter.
Does anyone else have a similar exhaust setup, and how is it compared to alternatives?
In researching muffler design on these cars, it seems the ones reported to have less drone (including the stock muffler) have a crossover element in the muffler that connects the left and right cylinder banks. I happen to have a tig welding setup here, and was thinking about fabricating a crossover pipe that basically would link the two muffler outlets together in perhaps a straight line. The idea is some of the sound pulse energy will reverberate into the opposing cylinder bank's muffler. (The pulses alternate between cylinder banks, so I think this will dampen the low order exhaust harmonic). I could tune it for lots of dampening (big straight crossover pipe) or little bit of dampening (smaller diameter crossover pipe, fitted further back towards the exhaust tips). I'm not sure if you guys can visualize this based on my description, but what do you think?
The other exhaust noise I want to get feedback about fixing is what I believe to be a rattling catalytic converter. It seems to only really rattle when it's hot. Metallic rattling like a loose heat shield (but I checked and tried to tighten those, but the problem persisted). It seems louder on the right/passenger side - especially with passenger window rolled down when driving near an object on that side (like a wall or in a parking garage).. I read about one guy here having noisy catalytic converters which he fixed by replacing them outright, but he had some other problems (like low power I think, and bad emissions results), and his car also had roughly double the miles mine (which is "only"110k miles. :) ). Has anyone else here had a fixed rattling catalytic converter somehow other than replacing it outright? Anyone know what exactly is making it rattle as it comes up to temperature?
Finally, is it ok to jack where I have indicatpictured below? Someone at a local porsche shop said they do it there all the time, but I got realizing it was supporting the entire weight of the rear half of the car through the two transmission mounts.
[img]http://s22.postimg.org/82hudt781/image/707nv9oel/
Thanks.jpg[/img]
Original Message
Author: jakeruDate: April 25, 2015 12:15AM
Exhaust noises
Hey folks,
I wanted to talk exhaust noises.
My 2001 2.7 Boxster I just got came with these after market mufflers:
http://postimg.org/image/v2ohq551p/
Although they sound amazing at higher engine speeds, they are pretty loud and "droney" at lower engine speed when under load. Not having the benefit of having tried a stock muffler, I'm not quite certain what to expect, but I think it could be a lot quieter.
Does anyone else have a similar exhaust setup, and how is it compared to alternatives?
In researching muffler design on these cars, it seems the ones reported to have less drone (including the stock muffler) have a crossover element in the muffler that connects the left and right cylinder banks. I happen to have a tig welding setup here, and was thinking about fabricating a crossover pipe that basically would link the two muffler outlets together in perhaps a straight line. The idea is some of the sound pulse energy will reverberate into the opposing cylinder bank's muffler. (The pulses alternate between cylinder banks, so I think this will dampen the low order exhaust harmonic). I could tune it for lots of dampening (big straight crossover pipe) or little bit of dampening (smaller diameter crossover pipe, fitted further back towards the exhaust tips). I'm not sure if you guys can visualize this based on my description, but what do you think?
The other exhaust noise I want to get feedback about fixing is what I believe to be a rattling catalytic converter. It seems to only really rattle when it's hot. Metallic rattling like a loose heat shield (but I checked and tried to tighten those, but the problem persisted). It seems louder on the right/passenger side - especially with passenger window rolled down when driving near an object on that side (like a wall or in a parking garage).. I read about one guy here having noisy catalytic converters which he fixed by replacing them outright, but he had some other problems (like low power I think, and bad emissions results), and his car also had roughly double the miles mine (which is "only"110k miles. :) ). Has anyone else here had a fixed rattling catalytic converter somehow other than replacing it outright? Anyone know what exactly is making it rattle as it comes up to temperature?
Finally, is it ok to jack here I have indicated below? Someone at a local porsche shop said they do it there all the time, but I got realizing it was supporting the entire weight of the rear half of the car through the two transmission mounts.
http://postimg.org/image/707nv9oel/
Thanks
I wanted to talk exhaust noises.
My 2001 2.7 Boxster I just got came with these after market mufflers:
http://postimg.org/image/v2ohq551p/
Although they sound amazing at higher engine speeds, they are pretty loud and "droney" at lower engine speed when under load. Not having the benefit of having tried a stock muffler, I'm not quite certain what to expect, but I think it could be a lot quieter.
Does anyone else have a similar exhaust setup, and how is it compared to alternatives?
In researching muffler design on these cars, it seems the ones reported to have less drone (including the stock muffler) have a crossover element in the muffler that connects the left and right cylinder banks. I happen to have a tig welding setup here, and was thinking about fabricating a crossover pipe that basically would link the two muffler outlets together in perhaps a straight line. The idea is some of the sound pulse energy will reverberate into the opposing cylinder bank's muffler. (The pulses alternate between cylinder banks, so I think this will dampen the low order exhaust harmonic). I could tune it for lots of dampening (big straight crossover pipe) or little bit of dampening (smaller diameter crossover pipe, fitted further back towards the exhaust tips). I'm not sure if you guys can visualize this based on my description, but what do you think?
The other exhaust noise I want to get feedback about fixing is what I believe to be a rattling catalytic converter. It seems to only really rattle when it's hot. Metallic rattling like a loose heat shield (but I checked and tried to tighten those, but the problem persisted). It seems louder on the right/passenger side - especially with passenger window rolled down when driving near an object on that side (like a wall or in a parking garage).. I read about one guy here having noisy catalytic converters which he fixed by replacing them outright, but he had some other problems (like low power I think, and bad emissions results), and his car also had roughly double the miles mine (which is "only"110k miles. :) ). Has anyone else here had a fixed rattling catalytic converter somehow other than replacing it outright? Anyone know what exactly is making it rattle as it comes up to temperature?
Finally, is it ok to jack here I have indicated below? Someone at a local porsche shop said they do it there all the time, but I got realizing it was supporting the entire weight of the rear half of the car through the two transmission mounts.
http://postimg.org/image/707nv9oel/
Thanks