RedpopSS Posted November 3, 2003 Report Share Posted November 3, 2003 I had my Flowmaster Big Block 50 series muffler installed on my SS. The external sound is incredible (very throaty and mean, love it). I was wondering if anyone else that has installed this muffler has noticed the considerable droaning noise inside the cab while excelerating? Also, will the droan quiet down at all as the muffler gets some more miles on it? Does anyone know of any tricks to help quiet it down, re-installing the stock muffler isn't an answer either I had a Flowmaster on my last truck (1999 Dakota w/ 5.2L V8) and didn't have near as much cab noise. Any insight would be great. Thanks in advance, Link to comment Share on other sites More sharing options...
rico750sxi Posted November 3, 2003 Report Share Posted November 3, 2003 Flowmasters are kind of known for their interior resonance. By the way, which FM did you put on? Link to comment Share on other sites More sharing options...
SSminneapolis Posted November 3, 2003 Report Share Posted November 3, 2003 you might want to check and see if there are any leeks in the welds...i had to go back and get a few fixed...can hardly hear a thing in the cab now... Link to comment Share on other sites More sharing options...
blackhawk Posted November 3, 2003 Report Share Posted November 3, 2003 Like stated above check the welds for holes, I haven’t mentioned this before but I had the same issue at first with a crappie weld job from the muffler shop. And to answer your question, yes the interior resonance does tone down a bit once you get the muffler broke in. I have 2500mi on the 50 series now and love the sound! Link to comment Share on other sites More sharing options...
TimB Posted November 3, 2003 Report Share Posted November 3, 2003 I have about 5000 on mine I love the sound and its not that loud inside. On the hiway no diff from the stock muffler Link to comment Share on other sites More sharing options...
mwalls54 Posted November 3, 2003 Report Share Posted November 3, 2003 i have about 7000mi on my flowmaster and it is a little nosie in the cab at diffrent rpm. my 2000 Z71 done the same thing i thought about putting dynomat all over the cab but i figured that would add about 50lbs or more so my solution is turn up the radio Link to comment Share on other sites More sharing options...
SuperDave Posted November 3, 2003 Report Share Posted November 3, 2003 You bought the wrong muffler. Flowmaster makes a certain group of mufflers called "Delta Flow" series. These give you the performance without the interior resonance or "droaning". They cost a little more, but are worth it if you want peace and quiet. They make pretty good power also. Go check them out at <www.flowmastermufflers.com> SuperDave Link to comment Share on other sites More sharing options...
ToddOH Posted November 3, 2003 Report Share Posted November 3, 2003 Like stated above check the welds for holes, I haven’t mentioned this before but I had the same issue at first with a crappie weld job from the muffler shop. And to answer your question, yes the interior resonance does tone down a bit once you get the muffler broke in. I have 2500mi on the 50 series now and love the sound! I don't understand how a Flowmaster Muffler would "break in". There is no packing in these mufflers, it has steel baffles. I've had Flowmasters on many vehicles they have never changed from the day I put them on. ??? Link to comment Share on other sites More sharing options...
slj Posted November 3, 2003 Report Share Posted November 3, 2003 I just had the Flowmaster 530504 installed. (50 series dual in dual out to the rear) I have to admit, the WOT sound is GREAT!! but, up to 50mph, it seems a bit slower in response. Tomorrow I'll be able to test the 70mph+ acceleration since I may see the difference there? (may have to compensate with a Radix!) Link to comment Share on other sites More sharing options...
rico750sxi Posted November 3, 2003 Report Share Posted November 3, 2003 Well, that stinks, I was very close to ordering that muffler. Link to comment Share on other sites More sharing options...
RedpopSS Posted November 3, 2003 Author Report Share Posted November 3, 2003 Thanks for all the info. I will contact the shop that installed it and see if they can take a look at the welds for me. I wondered about the welds myself, but didn't hear any noise under the truck at idle (that's about the only way I could check it). I don't think I bought the wrong muffler, I got the one with dual 3" inlets and a sigle 3.5" outlet. The muffler also came with the elbow piece to replace the factory Y that exits towards the tail pipe. With any luck some touched up welds will do the trick. I'll repost once I get it done. Link to comment Share on other sites More sharing options...
blackhawk Posted November 3, 2003 Report Share Posted November 3, 2003 QUOTE (blackhawk @ Nov 2 2003, 10:16 PM) Like stated above check the welds for holes, I haven’t mentioned this before but I had the same issue at first with a crappie weld job from the muffler shop. And to answer your question, yes the interior resonance does tone down a bit once you get the muffler broke in. I have 2500mi on the 50 series now and love the sound! I don't understand how a Flowmaster Muffler would "break in". There is no packing in these mufflers, it has steel baffles. I've had Flowmasters on many vehicles they have never changed from the day I put them on. ??? Everything has a break in period, I know it is doing something because from day one this muffler had gotten quieter and sounds better and better each day. At first there was a very distinctive “New Muffler” metal sound, like the muffler was resonating the sound back and forth on the brand new metal surfaces. Now with many miles on the new metal it must have been heated and cooled many times and is coated with carbon build up to deaden the sound waves bouncing around, now it has the true flowmaster sound that I purchased this muffler for to begin with… I also have ASM headers and those needed time to break in as well, I love the burly gurgle sound this motor makes… If you want the race car sound get a 40 series, the 50 series just sounds damn good and won’t drive you crazy… Link to comment Share on other sites More sharing options...
SSminneapolis Posted November 3, 2003 Report Share Posted November 3, 2003 it is true there is no baffle material inside the flowmaster mufflers...although there is a break in...as you stomp on it...deposits are made on the metal in the muffler...reducing the reflectivinty of sound...thus quieting it down...at a certain point there it stops depositing because there isn't enough fresh metal to stick to and the flow is too high...you get roughly the same sound WOT...but the resonance calms down... Link to comment Share on other sites More sharing options...
Black03SS_NJ Posted November 3, 2003 Report Share Posted November 3, 2003 Well, that stinks, I was very close to ordering that muffler. Link to comment Share on other sites More sharing options...
Black03SS_NJ Posted November 3, 2003 Report Share Posted November 3, 2003 I don't think I bought the wrong muffler, I got the one with dual 3" inlets and a sigle 3.5" outlet. The muffler also came with the elbow piece to replace the factory Y that exits towards the tail pipe. You definitely did not buy the wrong muffler. This is the recommended muffler for all 8.1 and 6.0 applications, and one 3.5" tailpipe should resonate less than the two 2.5" pipes that everyone runs. So your problem is most likely in the installation. I don't mean to sound ignorant, but it sounds like the "drone" you are hearing in the cab could just be the side effect of installing a performance muffler. The real problem tends to be resonance, which is basically a never-ending drone at 60mph or so. That is what you want to avoid. I think some increased "drone" on accelleration is normal for any performance exhaust. But I would get things checked out anyway. Link to comment Share on other sites More sharing options...
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