Davy, you've gone this far, if you want to go further, build two true resonating chambers (not a fiberglass packed straight-through type muffler everyone calls a resonator but isn't) and place them in the tailpipes after the mufflers. You may have to experiment to get the chamber volume (length) to work where you need it frequency-wise. See post #54 more more. Devon
You probably remember but just a reminder for everyone else... I did build the resonance chambers after the mufflers "post 71". The only thing I didn't do is experiment by changing the length of the pipe/chamber. With the 20 inch chamber the drone was slightly worse so I was extremely discouraged after paying for the fabrication of it. I couldn't afford having it rebuilt and reinstalled with another length which also had no guaranties I know I am not always making the best choices. I just hope I can learn from all of the wisdom from all of you to solve this issue.
Thanks, I'd forgotten. You must be willing to experiment with the chamber to make it work though, there is no "one size fits all" there. Sorry if that info comes too late. Devon
Resos off a late model stang are the prob. There are other threads out about drone and there are post about members results with aftermarket resos... not trying to be rude, but factory resos weren't built to be behind flowmasters. I bet the factory muff has way less drone than a flow master. this is why you still have drone issues with your factory resos
I am now actually considering going to some factory mufflers. I am guessing I will lose all of the aggressive sound and some performance I put those late model mustang resonators on there because they were "free" in hopes they would help the situation.
No updates yet. We couldn't get the mufflers off in Yardley's garage, so I'm going to an exhaust shop this Thursday AM...
Yes I actually already added a set of resonators. My first thought after the instal was that they actually made worthwhile difference. After driving the car for a few days I figure it perhaps reduced the drone by about 10%. Ironically they started making my idle drone slightly as well. It actually sounds like there is a really low base coming out of the stereo system.
The shop did a great job. I only had the car out for the ride home, about 45 minutes, but 30 minutes was on 45-50MPH roads in the 'drone-zone'. Car was quieter at idle, quieter at highway, and I believe the drone was significantly subdued. I would like to get more seat time before passing final verdict, and Ohio is coming up next week. So far, from my limited experience, I am happy with the switch.
Thanks so much for the update. I am really interested to know how you feel about the drone with a little more seat time. When I initially put resonators on my car I thought it helped out a lot for the 5 min. test ride back to the exhaust shop. The day after when I drove it around I was real disappointed when I concluded that there was next to no difference with the drone. In regards to the reviews on this muffler... What about the metal clanking from the flap and spring while it's cold?
The idle valve sound was my first critique...I barely heard anything over the BBB rumble. Again, I drove it for 30 minutes in the drone zone and so far, it is much quieter! I will report back sometime after Ohio.
I am extremely pleased with the new mufflers and would recommend them to anyone. The drone is subdued/gone, and car is quieter at idle and highway RPMs. It 'barks' when you're on it. Again, 17959 was recommended to me, but I've heard good results with 17159 as well. 17959 has a stiffer internal valve spring, and is recommended for 'closer to 8.0 liter' engines with good flow.
