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Vibration and noisy after exhaust install

I installed long tubes and full exhaust and now have a vibration after 3k and a drone in the exhaust on any speed over 80 and during hard excel in 4th or 5th???

Exhaust in a bind?

I also developed a moaning noise in the rear after Homestead a couple of weeks ago.

The noise is there motor on and off, turning the wheels and not turning the wheels, brakes and no brakes, in gear and not in gear....On stops about 10 feet from stopping.

Think this might be an axle bearing?
 
Darren had a similar issue with his exhaust so hopefully he'll stop by and help.
 

Sesshomurai

Yeah. Let me collect my links and info on this and reply in full later.Dont worry my friend. And welcome to the longtube club.

But do you have cats still or no?
 

Sesshomurai

thebull said:

K. Same here.

What kind of over-axles, mufflers do you have? Are they welded or clamped? Do you hear the vibration after 3k only when accelerating/moving or also while in neutral, sitting still?

I have the Kooks longtubes and H-pipe and Kooks side pipes. But I opted to go with the JPC stainless over-axles so I can re-use my GT500 mufflers. The Kooks overaxles have welded mufflers.

In my situation, the vibration rattle comes from the rear on engine throttle/load. When I open the side pipes some, the vibration goes away. Best analysis I've come up with is its the juncture where the mufflers clamp. It's binded or simply that the exhaust overwhelms the joint there (no matter how tight it is).

I'm going to tak weld the mufflers to the over-axles and see if that fixes it. Another option I might try are high-flow header mufflers that insert into the collection tubes.
 
I installed the kooks side pipes and left the rest factory. I get a vibration at very low rpm's. I know it's coming from the side pipes on mine. I believe my rattle is right where they bolt up to the body. The one bolt on the end. I noticed that the factory side pipes have a short flex pipe in that area. Maybe that's why it's there? I've thought about modifying with a piece of flex pipe but haven't done it yet. Living with the rattle for now. You guys with the long tubes, can you post a sound clip? Do they give you any hp increase? I've been thinking of doing that next. Right now my boss is pretty dang loud but I like that. Of course there is no hp increase in changing only side exhaust. At least I don't think so.
 
Steve said:
I installed the kooks side pipes and left the rest factory. I get a vibration at very low rpm's. I know it's coming from the side pipes on mine. I believe my rattle is right where they bolt up to the body. The one bolt on the end. I noticed that the factory side pipes have a short flex pipe in that area. Maybe that's why it's there? I've thought about modifying with a piece of flex pipe but haven't done it yet. Living with the rattle for now. You guys with the long tubes, can you post a sound clip? Do they give you any hp increase? I've been thinking of doing that next. Right now my boss is pretty dang loud but I like that. Of course there is no hp increase in changing only side exhaust. At least I don't think so.
Here's a vid I posted yesterday.

https://trackmustangsonline.com/index.php?topic=3959.0
 

Sesshomurai

Steve said:
I installed the kooks side pipes and left the rest factory. I get a vibration at very low rpm's. I know it's coming from the side pipes on mine. I believe my rattle is right where they bolt up to the body. The one bolt on the end. I noticed that the factory side pipes have a short flex pipe in that area. Maybe that's why it's there? I've thought about modifying with a piece of flex pipe but haven't done it yet. Living with the rattle for now. You guys with the long tubes, can you post a sound clip? Do they give you any hp increase? I've been thinking of doing that next. Right now my boss is pretty dang loud but I like that. Of course there is no hp increase in changing only side exhaust. At least I don't think so.

About 25-30hp with the no cat LT's. But I got the 1-7/8" tubes in preparation for a cog supercharger down the road.

Good point about the flex tube on the factory sides. I wonder if a flex segment can be inserted to the over-axle pipes to solve this common problem with rigid exhausts.
 
Awesome sounding boss in the video. Thanks for posting that. By replacing the side exhaust only. All it does is change the sound. It did drastically change the sound. I get a lot of compliments on that. But there is no hp gains that I can tell nor did I expect any. As far as the piece of flex pipe goes. I think ford put that there for a reason. It is needed. I guess kooks didn't think so but in my case at least it is needed.
 
Steve said:
Awesome sounding boss in the video. Thanks for posting that. By replacing the side exhaust only. All it does is change the sound. It did drastically change the sound. I get a lot of compliments on that. But there is no hp gains that I can tell nor did I expect any. As far as the piece of flex pipe goes. I think ford put that there for a reason. It is needed. I guess kooks didn't think so but in my case at least it is needed.
Compared to the stock 3/8" exhaust disc there is a 2-3 HP gain by running no discs and I'm sure the Kooks side pipes. So there is some gain in HP. ;D
 
A few more horsepower by removing disc is something I didn't know. The kooks pipes are bigger and less restrictive than factory sides. I was just going by seat of the pants feel. I can't really notice a difference. I do luv the sound of them. There is definatley room for improvement on the design and fit and finish. I wish I had access to a pipe bender. I could make my own and make them better.
 
Thanks guys.

All of mine connections are slip fit with a clamp. I think I might take to me chassis guy and have him put v-bands on all the connections.

The groan noise is all the time...It's in the shop now..I'll know more tomorrow.
 

Sesshomurai

thebull said:
Thanks guys.

All of mine connections are slip fit with a clamp. I think I might take to me chassis guy and have him put v-bands on all the connections.

The groan noise is all the time...It's in the shop now..I'll know more tomorrow.

Good luck. I'm anxious to see how to correct it. I'll wait to hear your results, but I might have to install these[1] in my over-axles or weld the mufflers on.

[1] http://www.summitracing.com/parts/sum-653010/kitcombocontents
 
I'm going to check the pinion angle too. I lowered the car and replaced the LCAs at the same time as the exhaust.
 

Sesshomurai

thebull said:
I'm going to check the pinion angle too. I lowered the car and replaced the LCAs at the same time as the exhaust.


I thought the same thing and just installed adj. rear upper control arm and tuned the pinion angle but the exhaust vibration persists. it's tolerable but I'll solve this eventually.
 
It just sucks because the car was so smooth before. I remember back in the Fox body stangs had a weight on the exhaust from the factory.
 

Sesshomurai

thebull said:
It just sucks because the car was so smooth before. I remember back in the Fox body stangs had a weight on the exhaust from the factory.

It was but it was designed for ride quality then. going for LTs and off-road exhaust is a major step towards race/track only setup. But the NVH can be addressed. there are options still.
 
I'm going to get to the bottom of this....or take them off and install the Hellion TT kit...LOL
 
401
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Any resolution to this? I have American Racing Headers 1 7/8, Boss X-Pipe, JPC Over Axles, and Borla 2013 Shelby Mufflers, and I am getting a nasty groaning/vibrating sound coming from the rear when I am sitting in idle and at low RPM. It happens for a couple seconds then goes away, then comes back. It doesnt always happen either. I first thought it was transmission related, like a bad bearing, but I can hear the sound in the exhaust (ear to muffler) and towards the back when sitting in the car.
 

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