Wanna get a new midpipe, but without the drone

[sunil6784]

I've been chasing down a nasty rattle, and I'm pretty sure i found it in the two upstream cats. I have a stock midpipe, 70,000 miles. When I hit those two cats, they make a funny rattle sound, much like the sound I've been hearing. I'm thinking about getting a new midpipe w/ cats. H pipe or X Pipe ? I need one that won't contribute to any drone, if possible....

 

[Jaswir]

i say go with a X with cats... really the muffler that has the drone... cats will help a lil

 

[HISSIN50]

Make sure the heat shields are not making the noise.
A catted system is quieter and should have less drone, though drone has to do with body resonance and not loudness (seems to me that the muffling of cats does help with the amplitude of drone though).

 

[sunil6784]

How can I tell if its just the heat shields? I Gave them a little wiggle and they were fine...the welds still look good.

 

[sunil6784]

ttt

 

[HISSIN50]

Heat shields sound fine then. It was just worth checkin real quick in case that was it.

 

[srothfuss]

I've been chasing down a nasty rattle, and I'm pretty sure i found it in the two upstream cats. I have a stock midpipe, 70,000 miles. When I hit those two cats, they make a funny rattle sound, much like the sound I've been hearing. I'm thinking about getting a new midpipe w/ cats. H pipe or X Pipe ? I need one that won't contribute to any drone, if possible....

Try doing a couple donuts and see if the heat sheild falls off... (sorry that happend to me once) If the heat sheilds were loose, that would mean that the welds broke off and they were just "flapping in the wind." You can try to pry them off of the midpipe. If they don't budge than it's not the shields. I will venture to guess that something inside the catalyist is loose and rolling around. I'll be replacing my O/R H with an X that has catalytic converters to cut down on some of the noxious fumes.

Resonance as JT was getting at is the result of a continual pusle of an audible frequency that is created from the mufflers in the cavity under the body of our cars. As the cross over pipe helps to improve exhaust scavanging it also helps to produce some of the resonance. As each muffler accepts an individual pulse of expeled gas it creates a pulse in the form of a sound wave. Then the oppisite muffler does the same thing (courtisy of the the cross over). So you now have alternating sound waves bouncing around underneath the car. Some of the sound is cancelled out, but some also hits the body in this "pocket" which acts like a giant tuning fork. And thus the drone.... strange....

 

[sunil6784]

Alright, thanks guys !

 

[mustangsquared]

I had a knock?ticking noise under my car...thought it was the thow out bearing...it turmed out the cat material inside the shell had broken loose and was bouncing around. I took a screw driver to both cats and knocked the material out so now I have a OR X-pipe....dont recommend it....too much drone.

 

[89LXRAGTOP]

I would suggest the Mac offroad pro-chamber.
Totally got rid of the 2k drone for me!

 

[legalize420]

I would suggest the Mac offroad pro-chamber.

+1

 

[rock4451]

i have an o/r x with 40 series delta flow flowmasters. has a bit of drone but not as much as say the reg. 40 series. sounds mean as hell from 2500-up. some people dont, but i happen to love the idle also. just my 2 cents