I just put a new flowmaster super 44 on my 99 grand cherokee v8. its very loud when i keep the rpms low, but when i give it more gas the sound begins to go away. Why is this happening? Do i have to break it in?is it becasue its cold here in michigan?(like 20 degrees out)

 

is it backwards?

 

no. its a chambered muffler. nothing will ever change.
I believe what you hear is probably resonance in the muffler or "drone".
the exhaust gasses resonating in the muffler reverberate inside the vehicle. when you gas it and change the rpm it affects how the gasses flow through the muffler. the mor you drive it I bet the more you can pick out where it does it. sometimes its at a certain rpm and load. Especially on the highway usually.

 

Do you have it so the tail pipe turns down below your xj?

 

what would i have to do to make it louder when i reaches high rpms? new cat? or what?

 

It most likely is, you just can't tell from inside. Have someone drive it so you can hear what it really sounds like

 

Why in the hell do you want it louder? Let me guess, you're under the age of 25, right? Loud don't make power, it only pisses people off and makes all Jeepers look bad.

 

Im sure its probably plenty loud outside, have someone rev it up for you while you are outside of it, maybe have them do a drive-by or two. Higher RPM's can seem quieter since everything else is making louder noises, along with the exhaust pulses becoming a little smoother due to higher velocity, basically things dont quite resonate like they would at high speed vs low.

If you really want it louder then run a straight pipe (kidding). Cut tailpipe and install a turndown after the muffler. Afterall the super 44 is a quieter delta-flow muffler, an original 40 series would be louder, or you could even go with an ultra loud super 10 series 1 chamber. If you were close I would probably trade my 40 for your 44.

 

No muffler is the best for v8 in my opinion. Sounds bettr and louder than the flowmaster I tried

 

Wow that's a little harsh. My jeep is loud because I like the way it sounds and that is what matters to me it makes me happy and I'm over 25

 

Personally I like the Borla XR-1 over FM or even the Powerstick chambered muffler.

 

Don't get me wrong, I love the sound of a good exhaust, but any louder than a Flowmaster is just annoying and draws too much unwanted attention.