Cozmo

A couple of weeks ago, I posted a question about Magnaflow mufflers. I got some great feedback and ordered them. I had them installed on Wednesday. They look and sound great. There is however some resonance at low rpm's with the windows rolled up. Any suggestions?

Cozmo

Dark-Knight

Did you also install the x-pipe? If not that may help.

I went from muff elims to Magnaflows, had the x, so to me reasonance is a thing of the past. THe Magna's :smash: the reasonance.


[Modified by Beautiful Beast, 4:00 PM 11/22/2003]

LT-4 CE

I have the Magnaflows and have removed the resonator all together, replacing with straight tubing, but my LT-4 has a factory H-pipe.

Resonance is very minimal except in 6th gear going up hill between 60-65 mph.

Cozmo

I don't have an x pipe. If I get one it will have to be after Christmas. Hmmmm . . . . I wonder if my wife would get me one for a stocking stuffer. In the meantime one of the guys in my local club suggested acoustic insulation under the carpet in the rear.

McShagger

Dood, looks sweet! Give it some time... it may go away by itself. If not, I dont think there is much you can do to fix it. Im sure a lot of people will say: add an X-pipe; add a crossover pipe; change the rubber on your hangers; try lowering the tips; try extending the tips; sound proofing; add reasonators... etc... I dont really think any of this will fix the problem. It may help, but I doubt if it will fix it. A lot of it is hit or miss and just costs money. However, I really dont have any experience with it and you may want to ask around. From what Ive read here on the forum, reasonators are your best bet. The rubber on the hangers may work too. I remember reading one guy doing that and it fixed his reasonance.

ZR-71

I don't know the physics of it, but at lower RPMs there's always more resonance.

But the MagnaFlows sure sound mean :D

Cozmo

Yeah, they sound mean! About a dozen of us from the local club went on an informal tour through the Texas hill country and went to about 4 dive bars along the way. Even the Harley group we ran into complented me on the looks and sound. I gotta say, I think my exhaust sounded the best of everyone there! Guess I'll just tell the wife to wear ear plugs when she's in the car. :cheers:

McShagger

It shouldnt be that loud... although, mine where pretty bad the first coupld of days I had them. Then the reasonance went away. Try giving Magnaflow a call... The techs there may be able to help you.

Cozmo

So, in a little time or a couple of days it could cure itself? Hmmm . . . . . I don't understand that, but what the heck. Stranger things could happen. I've seen and heard it! :cheers: Thanks for the advice about calling Magnaflow. I'll try it if it doesnt go away.

knp

I had my Magnaflows installed on my '92 last Monday. I've noticed the same resonance at light throttle Unfortunately I was only able to drive the car a little bit on Monday and Tuesday.

Did you notice a faint burning-plastic smell coming from them after you shut off the engine?

Cozmo

I noticed a burning smell when I was stuck in stop and more stop traffic on the freeway on the way home from the shop. It went away after a couple of outings. I dont drive my car as a daily driver, so "a couple of days" might mean something different to someone who does. I drove the car on Saturday quite a bit, all the time with the windows down. It was awesome! I was having too much fun to check for resonance. The weather here tomorrow is supposed to be cool and full of sunshine. I will drive with the windows up and get back to you. I hope break in period works.

knp

Thanks!

4-ACES

Hey Longhorn,
Did you get these welded on or did you just clamp them? I've had mine about 2 months now and drove them with just the clamps for a while. I finally made it over to a custom muffler shop and had them welded. Believe it or not it really firmed up the install and reduced some of the interior resonance,
although I really did'nt have much to begin with. My plan is to add some extra insulation under the rear carpet deck and the wells behind the seats.
I've noticed that without some dampening in those storage wells you'll get a kind of low frequency echo effect. Thats just a fiberglass box that acks like
a low frequency amplifier when theres nothing in it.
BTW...The Magnaflows have also mellowed alittle since they have some miles on them . When the guys in the Camaros and Z28's hear it, they don't want any part of me now. Imagine that. ..... :thumbs:

BlackC6LS3

so how do you like the diference between the 2 setups?

vetteman9368

whats teh cost on em?

Cozmo

I bought them from a guy on ebay named performancepeddler for 340. They were $370 shipped to my door.

Cozmo

I had them welded on. Youre the second person that told me that they mellow in time. Thats kinda weird! I still plan on adding a little acoustic insulation. :cheers:

Cozmo

Cozmo

Sent you an IM.