BBK O/R X and Flowmasters not sounding good!

[Chi-Town Tom]

I have a '99 Cobra 'vert. I installed a BBK O/R X pipe today with the Flowmaster CB that was on the car and now there is a terrible rattling noise coming from the mufflers as if there are loose baffles, there was no issue prior to the X pipe install. The pipes are tight and clearance is good. The sound occurs on part throttle acceleration between 2 and 2500 rpm, and on decel at the same rpm. I knew there would be some raspy sound but this isn't right.
Do the Flowmasters not work well with X pipes?
Is there a better C/B to use with the X?
Should I get an H instead?

Thanks in advance.

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[Ear Rak]

loose o2 maybe?

 

[01Cobra]

I took the cats out of my bassani x pipe and I have a bassani catback. It sounded like dogshit. I promptly put the cats back in. Less volume great sound.

 

[2k4gt]

ya i had that problem two with the x pipe and the flowmasters it sounds like the thing is going to fall off the back would say get new cat back cause the bbk x pipe i have put on other cars and it sounds great :biggthump

 

[FirstWorldProblems]

I had the same setup and it sounded sick, but also got a new exhaust leak every 2 seconds. Make sure it's not leaking

 

[Chi-Town Tom]

All connections are tight and no leaks. Any suggestions on cat backs that will sound good with this X pipe?

Thanks.

 

[Slow99x]

Magnaflow

 

[TaintedSnake01]

loose o2 maybe?

+1, I had a loose 02 sensor and it sounded horrible at low rpm alot of rattling sounded like i had a bolt inside my midpipe. Make sure your 02's are tight

 

[2k4gt]

Borla:biggthump

 

[Since 1964]

My guess is the "X" is causing trouble. How, I do NOT know, but it should be because of the way the flow moves with an "X" as apposed to an "H" pipe. I'm thinking there's too much pressure with the "X".

Try calling Flowmaster, I bet they know, or call the "X" pipe people.

 

[Ear Rak]

actually X gives less pressure, but tends to give more of a raspy sound

 

[99 Stangbanger]

I had the same shit happen to my 99 cobra.

I had a Flowmaster CB and when I installed the new BBk O/R X, it sounded just like my mufflers has metal loose in them. Terrible Ratttling noise coming right from them. NOT THE X. I put the car on a lift and started it, reved it up and followed he noise right to the mufflers. Not just one Muffler but both had the rattling noise. They to were new, less then 30 days old. Thinking they were 2 bad mufflers, I called Summit where I bought them and told them about it. Summit then sent me out a replacement CB over night. Awesome CS I must admit:biggthump. Put the car back on the lift, installed the new Flowmaster CB.

Fired the car back up. Didnt hear anything right away so I figured it was the mufflers. Took the car off the lift and left. Got about 2 miles away and did a few little rolling hits and the fricken rattle came back while down shifting. I was so FN pissed!:argue: I was like.. your FN kidding me, 2 sets of mufflers went bad. All my FN luck.

Opted to put the Factory catted H-pipe back on for shits and grins till I decide WTF I was going to buy or do next. To my disbelief, the rattle noise went away and the mufflers sounded as good as a Flowmaster will. Jumped on the car in every gear, down shifts and all. ZERO RATTLE!

Sold the X pipe on ebay with a unhappy review about its noise. It had about 40 miles on it and 100% flawless condtion. Kid who bought it emailed me saying that he to didnt lke the raspy noise it made on his 99 cobra and that it also made his Flowmasters sound broken. He to sold it on ebay as well and went to the ORH as did I.

If I was you, buy the Mac Prochamber and dump that X.

 

[blownstang]

I've heard that the bbk x pipes do not sound good with chambered mufflers. My ARH longtubes, catted x, and flows sounds sick! So, i'm not sure if it's just a bbk thing, or a stock manifold/x pipe/flows thing.

 

[Mr Twigbert]

Let me guess... You have this sound:

http://videos.streetfire.net/video/99-Cobra-w-BBK-X-Pipe_160921.htm

Get rid of the X-pipe and pick up an MAC O/R H-pipe.. You won't be sorry!

 

[99 Stangbanger]

Let me guess... You have this sound:

http://videos.streetfire.net/video/99-Cobra-w-BBK-X-Pipe_160921.htm

Get rid of the X-pipe and pick up an MAC O/R H-pipe.. You won't be sorry!

The rattle in mine was just like that but louder. I to went to the Mac ORH and then the Prochamber and as always the H rocks! Deep & aggressive souding.

Has to be the way the gasses cross over the X and out to the Chambered mufflers.

I dont miss that sound one bit. I went about 40 miles and yanked that mutha right out.

Edit:
You say it came from the X tho. On mine, when the car was on the lift, two others and myself under there and we all heard it comming frm the Blowmasters not the pipe. EIther way, its meesed up!

 

[[email protected]]

You may not think so But the tail pipes have allot to do with that sound....I have a x with the flowmasters and it sounded just like that.
At first I had the spintech kit on it and it was that sound I thought it was the spintechs so I took it off and put the flowmasters on and the sound did not go away, I was just about to do the h pipe, I had an older 4.6 mustang with the h and loved it but before I did that I cut the tail pipes off and started the car, the sound went away and the thing was loud and good, so if you want the car to be loud I would take the tail pipes off and see what you think before you spend the extra money on new things.

 

[Chi-Town Tom]

Yes that sound in the vid Mr. Twigbert has linked is the sound that I have and it is 10 times worse in person!

I am torn between:
Keeping the X ang getting a Magnaflow cat-back.
Keeping the Flows and getting a Mac O/R prochamber to replace the X.
Keeping the Flows and getting an O/R H to replace the X.

Victor Ford show is Sunday, so hopefully I can hear the various combos in person.

Thanks to all who replied!

 

[Ear Rak]

flowmaster 2 chamber 40 series and an offroad H