Stainless Magnaflow installed today, Not the sound I wanted

**Djemcee** · 10-20-2004, 01:49 AM

I went to my muffler shop today. They installed the stainless 14" magnaflow mufflers where the old muffler used to be and then came out INTO some nice tips. He cut out the reasonators. It now has a very bad vibration noise at around 1500-1700 rpm range. It's just right before it changes to the next gear. If you bring it to the highest rpm range and hold it FROM changing to the next gear it sounds like Rosie O'donnell in the back with a 4 stroke vibrator. We both went for a ride and he said that the muffler is causing a harmonic vibration with the car. it almost sounds like the back of the car might be vibrating and maybe it could just be the inside back plastic panels were the speakers are. He said come back tomorrow and he will try adding magnaflow reasonators. I really wanted to avoid resonators, but I can't stand the freaking weird vibration. I also wish it were a little more deep and throaty sounding. Might have to switch out the 14" with something different. I am a little disappointed. :?

**gone2vegas** · 10-20-2004, 02:49 AM

aaah the joys of a wagon. all that empty space back there makes wagons prone to drone and vibration. 14" sounds a little small too.

why didn't you want to go with resonators? was it a matter of cost?

I say try either 40 or 50 series flowmasters with the resonators or bigger magnaflows.

**Djemcee** · 10-20-2004, 02:51 AM

Cost was no object. The muffler guy picked the 14". I though resonators take away FROM the sound? I don;t think it's loud or growly enough. I thought throwing resonators would just make it quieter?

Chris

**tonyt** · 10-20-2004, 08:09 AM

I have Flowmaster 40's and have the same problem. I haven't gone back to the shop yet, but I'm thinking it may be that I have 2.25" pipes and it's causing a bad echo vibration.

Some thoughts I had were to:

A) Move the mufflers back to wear the resonators used to be.

B) Install some resonators that will allow it sound deep and throaty.

C) Get some resonated tips.

D) God forbid, change out the mufflers with some spintechs or something along those lines.

The Flowmaster site says that the 40 series has a lot of interior resonance, so I might be forced with replacing them. Unfortunately, I've already soaked 400 INTO this exhaust and I hate to DROP even more INTO it.

Let me know what you end up doing with yours though...

**MagnumFreak** · 10-20-2004, 08:32 AM

Originally Posted by tonyt

I have Flowmaster 40's and have the same problem. I haven't gone back to the shop yet, but I'm thinking it may be that I have 2.25" pipes and it's causing a bad echo vibration.

Some thoughts I had were to:

A) Move the mufflers back to wear the resonators used to be.

B) Install some resonators that will allow it sound deep and throaty.

C) Get some resonated tips.

D) God forbid, change out the mufflers with some spintechs or something along those lines.

The Flowmaster site says that the 40 series has a lot of interior resonance, so I might be forced with replacing them. Unfortunately, I've already soaked 400 INTO this exhaust and I hate to DROP even more INTO it.

Let me know what you end up doing with yours though...

A. May help some. These hemi engines generate alot of resonance. That is why DC had to design the exhaust like they did.

B. Helped in my case with the aero turbines. The extra resonator shifted the resonance to a different rpm range. 95% of it is gone at highway speeds. I now have two mufflers and 4 resonators on my car. The additional resonators do not effect performance. I tested mine before and after the addition just to see if there was a difference.

C. According to my muffler shop. Resonated tips help very little. Not enough area to help with the noise.

D. If you look at the Borla system in detail they actually use two mufflers. I believe they are 19 inch for the main mufflers and 14 inch for the ones near the tips.

I added soundproofing to the back of my car in the area where the spare tire sits and on the back hatch. Not really a noticeable difference. Alot of effort with little reward.

If you have some ramps, get under the car and look at the exhaust to make sure nothing is near something that would allow vibration to resonate INTO the cabin. For instance, people who are installing the Borla system are saying that there is a cross member that is really close to the mufflers and they are adding a couple of washers to the cross member to move it further away.

Just my experience and random thoughts. Hope this helps.

**tonyt** · 10-20-2004, 08:48 AM

What about going to larger pipes?

It's funny you should talk about the cross member. I had to take it back once because my pipes were tapping the cross member when I went over a bump. All they did was bend the hangers. Could be that it's causing the vibration, but it sounds more like the pipes may be a restriction for the air flow and is causing the vibration.

**MagnumFreak** · 10-20-2004, 09:57 AM

Hadn't really thought too much about larger pipes. It will definitely change the sound and may change the resonance to either get rid of it or shift it to another rpm level. Find a good muffler shop and talk with them about it.

**bigdaddyoc** · 10-20-2004, 11:30 AM

Hey DJ I used the magnaflow reonsators with my Spin Techs and it came out pretty good. Good sound and little to no resonance but it might not be loud enough for you. I would let you CHECK it out but if you read my post about a blown trans seal you know I don't have my $@#&@ car.

**Djemcee** · 10-20-2004, 01:15 PM

I am supposed to go back today, but with the rain who knowes. You know us California's can't drive if it rains. Anyway, I think I will add the resonators and see what happens. I want to go back to the shop and tell him deeper, louder, and no top end vibration. Seems when the note starts to get higher pitched is when the vibration kicks in. And the high pitch note seems to come at the top of the shift. I think if we could just cancell out the note like you do with a crossover on a speaker, we would be in heaven. This muffler guy is amazing though. He lets you get under the car with him, he lets you touch and play and he gets very excited about exhaust. He was so excited yesterday to hear how his project turned out, after we road in it, I though he was going to cry. But he said, bring it back and we will get it right. He's about 35-36 and just has a huge passion for exhaust and cars. He just got off the SHOW Overhaulin, cutomizing a car on TV. He is in Corona, Ca - J-Sin's B&M muffler. I'm not trying to plug to much, but when you find someone in the car niz that likes what they do and does it great without trying to screw you over, you get excited to tell people about it. We will get it right and I will post you on the progress.

**bigdaddyoc** · 10-20-2004, 03:23 PM

I almost went to them. I ended up going to Z Performance in Corona. The have done 3 cars now for me and every time is a clean install for a good price.

**gn300** · 11-10-2004, 11:48 AM

Can any one match the sound of a rumble bee they sound mean its still a hemi but mabe too loud for a mama mobile? Oh stirr the station wogon pot see whet you get!!

**joseph** · 11-10-2004, 12:28 PM

Could it be the X pipe?
I had an H pipe welded on my 95 SS and it resonated like crazy, and a month later I went back to the muffler shop and got rid of the H pipe and the resonance was gone.

**Rev.Hammer** · 11-10-2004, 02:29 PM

Then a second x should kill that. I am thinking that a simple pair of cheap cherry bombs mufflers added as resonators would take car of it without reducing flow or true loudness

**Rev.Hammer** · 11-10-2004, 11:27 PM

just found out about these and I think that they would help.

http://www.secureperformanceorder.co...ore/vortex.cfm

**redinorange** · 12-02-2004, 07:49 PM

I'm new to this website, but I've read every post concerning exhaust while modifying mine along the way. Before I found the site, I changed out the stock resonators with 3A Racing resonators. This helped a bit with performance and mileage but did nothing to change the sound. This afternoon I had the muffler shop remove the suitcase and install straight pipes FROM the crossover in front of the suitcase back to the resonators. I like the sound but I get the same annoying vibration described by others on this thread. I'm not so sure that the resonance is part and parcel to the low rumble that is so coveted. I'm going to try the sound deadening material in the spare tire well and work with the muffler installer to eliminate the vibration. Oh the woes of plowing new ground.