Weird Noise From Side Pipes....Search Performed...Additional Questions

[Sledge]

Before and after shots:

It does not rattle, it is a little quieter, and does not choke off power, but then I'm only making about 420 hp at the flywheel.... If I get tired of these inserts I can put others in easily. Some looks are sacrificed for this setup but it sure is convenient.

Cheers

[Gus M]

Finally got to drive my new Backdraft but I'm hearing what appears to be this annoying rattling when the car is deaccelerating, as if the heat shields are ready to fall off. What is that? A major distraction!

[Gus M]

Finally got to drive my new Backdraft but I'm hearing what appears to be this annoying rattling when the car is deaccelerating, as if the heat shields are ready to fall off. A major distraction! What is that?

Any insight is appreciated.

Thanks

Gus

[novasscnc]

I had the same problem im guessing itis loose baffles on the inside and below where you can not see drill a pilot screw then use I think it was a 1 inch self tapping screw into the baffle it worked for me

[Gus M]

Originally Posted by novasscnc

I had the same problem im guessing itis loose baffles on the inside and below where you can not see drill a pilot screw then use I think it was a 1 inch self tapping screw into the baffle it worked for me

So is this a defect in the side pipe exhaust?

[Cashburn]

Originally Posted by Gus M

So is this a defect in the side pipe exhaust?

It's a characteristic of the type of baffles they use.

[MKS427]

I had a similar sound from my FFR pipes. It turned out to be a crack in the body of the side pipe.

[Gus M]

Originally Posted by MKS427

I had a similar sound from my FFR pipes. It turned out to be a crack in the body of the side pipe.

Was the crack visible to the eye or did you need to take it in?

I've seen my exact same car, with same equipment that DID NOT have the noise I'm experiencing.

[Mark Brye]

Originally Posted by Mark Brye

I had a sound similar to what you guys are talking about. I pulled the side pipe off and put it on my bench and started taping on it to see if I could make the sound. What mine turned out to be was a rock that made its way in between the four primary pipes and made its way down to the collector on the outside of the exhaust. It made a horrid racket. Turned the pipe on edge and the rock rolled out.

So this has happened twice now in the 14 years I have had my BDR. Little rock between the 4 to 1 side pipe collector. On outside of exhaust but rattling between the 4 tubes. Made a real racket both times. Had to take side pipe off and turn on end to get the bugger out.

[CHANMADD]

The reason is the flat surface in the picture.....as the air exits , it causes wierd vortices in the pipe..right there ....the way to fix is to cone the exits there into the pipe for a smooth exit transition.

[Gus M]

Originally Posted by CHANMADD

The reason is the flat surface in the picture.....as the air exits , it causes wierd vortices in the pipe..right there ....the way to fix is to cone the exits there into the pipe for a smooth exit transition.

Educate me on how to fix this...what does that mean to "cone" the exits... Sorry for my ignorance on that issue.

[jeffgrice]

Originally Posted by Cashburn

It's a characteristic of the type of baffles they use.

I also have a similar sound on my SPF Daytona Coupe with a 427sr. So I suspect your are spot-on cashburn it is the characteristic of the pipe design.

Thanks

Jeff

[CHANMADD]

I just wish it was easier to post pictures......I could sketch what I mean.....I always make my own pipes and experienced this in the one setup I had.....it's definitely what I said ...it's like a flatulant type of sound on deceleration. On deceleration the air is drawn back into the pipe and hits that flat brick wall and rattles everything..
https://www.google.com/search?q=insi...Nw7dT2Ka4BxpxM

[redvettx2]

So I have that noise on the right side pipe. During the PPI the dealer said loose baffle. Any one with a fix?

[twobjshelbys]

Originally Posted by redvettx2

So I have that noise on the right side pipe. During the PPI the dealer said loose baffle. Any one with a fix?

Are your mufflers "glass packs"? One side of mine started failing and my mechanic said they could be cleared out but we never did it. His recommendation was to simply clear both sides because they don't last long. There is an ad that appears on the top of the page from a place that specializes in Cobra exhaust. Perhaps they can answer your question.

[redvettx2]

I heard one guy mention a rock in the pipe and the more I listen the more I think there is rock in the pipe.

[BDR0572]

Originally Posted by Cashburn

Your first car came from us and did not have a Smeding engine... But I don't know if the noise you are describing is in fact what I am stating is the norm. Unless you guys are both unique at the same time? It's not something our customers are complaining about. So perhaps you need to YouTube it and/or get your dealer to work on it with you?

The current pipes are produced by the same company building far more units for several other BIG kit car companies and again not seeing these complaints on their forums or here.

Are these the new Gas N pipes? I had that exact issue but traced it back to the mount brackets in back not pinching the bracket(mount ) had to shim them so they would tighten up, sound great now worth a look

[novasscnc]

loose baffle maybe i used stainless sheet metal screws on the inside

[CHANMADD]

So I notice that the exit in the picture shows a flat surface with two exit holes. What you are hearing is the air hitting against that flat surface when it sucks back.. ill bet on the overrun it's worst. not to mention that those welds are kak and probably make some of the noise. Why spend money on big flow valves and heads and cams and have such a ****ty exhaust. I'd post pics of mine but it's a nightmare to get a picture on here . Brent , I would have thought you would have fixed this by now cheez.

[CHANMADD]

It would be better to have one smaller diameter tube with a flared end.