Hey guys. So i installed a magnaflow 14815 muffler on my car approx. 1 yr ago.

First few days, it was pretty quiet. Almost stock-like. After a few days, the sound was absolutely perfect. Deep tone at low rpms, amazing when you're on it, and quiet on the highway. Next to zero drone.

From the last couple weeks, i've been noticing, its extremely droney between 2200-3500 rpms when your at 1/4- 1.5 throttle. Its pretty loud, louder than in comfortable with. Hurts your head a little lol.

I got under the car thinking i got a hole in my resonator or something but i found no leaks anywhere. All the noise seems to be coming from the muffler itself. It just sounds really droney, and hollow-like.

Anything i can do to fix this? Any way to tell if the muffler has failed inside or something? I dont know much about exhausts so im pretty much a novice.

Any helps or tips would be appreciated from people with a 14815.

Thanks guys

 

Could have blown out the sound deadening material. Believe there is a warranty if it fails.

 

Thanks for the response. Any way to confirm this for sure before i actually get in touch with magnaflow? Like, how would you be able to confirm while its still on the car i guess is what im asking.

Kind of want to know the smartest way to go about this so i can fix my issue. I mean, i guess there isnt much i really CAN do unless i swap it out for a new one.

I guess my question is, what do i say to them to get them to warranty it lol.

 

Tell them it was fine before and then it started to drone like śhit and if they dont take care of u ur gonna put them on blast on the G35 forums lol.

 

Lol ill give that a try. I got it off of amazon, so maybe ill try contacting them about it and see what they do. Hopefully i can get a replacement and it wont i hope it wont happen again.

 

The wear in and get louder sadly. I was equally disappointed with mine.

 

Well that sucks. Still got yours on or did you go with something else? Amazon sent me a new magnaflow at no charge, but ill be pretty upset if it does the same thing.

 

It's inherent in that design, when they're new they absorb sound better. Glasspacks do it, Magnaflow, Totalflow, etc

 

Thats a bit annoying, and too bad. The magnaflow sounds perfect when new. At least i got a new one for free i guess. Is there any other muffler that sounds similar, but does not get louder overtime?

Also, i want to make the sound a bit better. I see many videos where people have added an hr y pipe, and coupe midpipe. Will this make a difference on a 2006 g35x?

This is what i want, pretty much exactly, soundwise. Sounds absolutely perfect! He's got a coupe midpipe, hr y pipe and magnaflow muffler.

I guess my question is, what year/model y pipe an i looking for, and what year/model coupe midpipe would i be looking for. Lots of differnet info on multiple threads, kind of hard to get an exact answer. Thanks!

https://www.youtube.com/watch?v=6AQ9_Tz8Ezc

 

Sound deadning material is shot.

I had that issue when custom making my setup.


currently running XtremeTechnologies straight through muffler for the middy, and the hks axle back.

i modified the hks to be a true 3inch, not the 2.5 it comes with.

0 drone, 0 rasp

up front
kinetix headers
high flow cats
2.5 to 3 y pipe
3in 3out xtreme technologies 14in x 6in oval racing muffler.

 

So after a bit more research. I noticed posts on here saying that the x y pipe is very similar to the hr y pipe, so no point to change it out.

That leaves the midpipe. I believe after more research a coupe midpipe will drone more than the stock sedan.

That leaves me with basically one option. Live with my current magnaflow until it becomes unbearable, then install the new one i got for free. And continue the cycle lol. Its unfortunate because the magnaflow sounds GREAT when not 'blown out'. Tbh i havent really noticed it droning much lately.

I think the only difference as to why i had more drone is i had more people always in the car when i started my thread. With the holidays gone, its back to me alone in the car.

​​​​​

 

Stock Sedan has a midget casket underneath. Weights like 80 or so pounds.

Super restrictive. Coupe middy is much nicer, will have some drone but will definitively sound better than a blown out magnaflow. I had the magnas in my first attempt and it was like empty folgers coffee cans.

If you can dish the cash, look into Extreme Technologies racing mufflers. Weight is like 8 or 9 lbs work AMAZING!!

 

Thanks for the reply. Im actually really interested in buying a motordyne plenum spacer so might be pulling the trigger on that soon. I think my final choice is going to be to stick with magnaflow for now. I bought this car for $3k so im not looking to put an insane exhaust on it and the magnaflow does sound amazing. Just wish there was a way to keep the good sound on it and keep it from blowing out eventually. There must be a solution.

 

Few questions you have to ask to come to the root cause of your issue.

What is this magnaflow..

Is it a straight through, or does it have baffles?
What are the dimensions
width hieght depth
inlet , outlet

What type of packing? (Stainless/fiber)



Ps ext tech is like 130 bux.


As for your car, if I recall correctly:

Motordyne spacer, mrev2 lower plenum, stock intake with k&n drop in filter yield close to 20 to 30whp

There was someone who ran every single intake combo on this forum and created the mother of all intake dyno tests on the same day and that proved to be the absolute best combination. May want to look into this.

 

After looking, it appears as though this muffler (14815) is a "straight through" muffler.

Yeah im up in canada so shipping costs suck ***. The plenum spacer is a good $400+ to get here which is just great. One mod at a time i guess lol.

Ive gotta get my car to the exhaust shop anyways cus the heat shields on the y pipe are rattling like hell. Going to see if they see anything wrong with it from a professional perspective.