 » Site Navigation | | | | » Recent Threads | | | |  |  |  |  09-23-2005, 05:35 PM | #1 | | Senior Member Join Date: May 2004 Posts: 411 |  Making exhaust quieter?
After the cats, I have dual 2.5" pipes going straight to a dual in and out magnaflow muffler. At partial throttle, under 3000rpms, there is a rediculous drone with a very deep sound coming into the cabin, and also heard from 3 blocks away.
The car has only about 200 miles on the exhaust, at which point is this supposed to get better? Do I need resonators, or do they serve another purpose?
What about some kind of electronic valve on each pipe that has a throttle like butterfly that is half open until I WOT, then it opens fully? Where do I find this?
By the way, after 3000rpm, full throttle sounds ABSOLUTELY SEX. Sounds like the devil gargling methanol |  |  | | 10-03-2005, 02:32 AM | #2 | | Junior Member Join Date: Dec 2004 Posts: 12 |
I have a 332ti with the AA center pipe (cat delete) resonator going into the Rogue Engineering DMS mufflers, same droning issue. So far I have learned to live with it... I will watch this thread to see if you find any creative solutions. As far as the butterfly... I found these tips in a JC Whitney catalog... never tried them though. http://www.jcwhitney.com/autoparts/P...001736/c-10101 | | | | | 10-05-2005, 07:41 AM | #3 | | Senior Member Join Date: May 2004 Posts: 411 |
Quote: | Originally Posted by rotation I have a 332ti with the AA center pipe (cat delete) resonator going into the Rogue Engineering DMS mufflers, same droning issue. So far I have learned to live with it... I will watch this thread to see if you find any creative solutions. As far as the butterfly... I found these tips in a JC Whitney catalog... never tried them though. http://www.jcwhitney.com/autoparts/P...001736/c-10101 | you got another link, that one doesnt work | | | | | 10-30-2005, 05:57 PM | #4 | | Junior Member Join Date: Dec 2004 Posts: 12 |
The link works fine for me. | | | | | 10-30-2005, 07:48 PM | #5 | | Senior Member Join Date: Aug 2004 Location: state college, pa Posts: 3,431 |
Here's the functional part: __________________
I scream, you scream, we all scream for ZOMBIES. | | | | | 10-31-2005, 06:30 PM | #6 | | Senior Member Join Date: Mar 2005 Location: Portland Or Posts: 2,666 |
Sure fire way to melt your cat down....
Likely burn valves.
Ruin O2 sensor.
Dave __________________
Dave - PDX
1995 318ti - Active Black and Tan.
2005 330xi - Mtech 1 - 6spd - Orient Blue/Black | | | | | 10-31-2005, 11:09 PM | #7 | | Senior Member Join Date: May 2004 Posts: 411 |
Wow, thats EXACTLY what I was looking for. As long as it doesn't close all the way, it should be fine for the safety of the rest of your exhaust. I'm gonna ask them about it, and most likely order a set. Cheaper, and probably quieter then adding resonators. I'm guessing its spring loaded, opening more with greater pressure under heavier throttle. Even under Idle I'm pushing a lot of air, so I'm guessing it would keep it partially open | | | | | 10-31-2005, 11:13 PM | #8 | | Senior Member Join Date: May 2004 Posts: 411 |
http://ultrafitexhaust.com/news_01_2001.htm this link tells that in idle, its still partially open, but DOES hold gasses in the cat longer. This might become an issue with the more restricted stock exhaust, but in my situation it should be fine. I'll call the vice pres tomorrow as on the link | | | | |
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