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

[ASO544]

What's the cost and the amount of flow loss you think?

[BDR427R]

Can anyone post a pic of what the new less restrictive pipe interior looks like?
Much Appreciate.

[Cashburn]

Originally Posted by ASO544

What's the cost and the amount of flow loss you think?

We built the table to do this. I am waiting on mufflers to get here so we can experiment.

[Sledge]

Folks:

An alternative to consider is to cut off the old sidepipes after the collector, and just after the pipe flares from 3 to 4 inches, get a spiral insert (Spiral Turbo Specialties) and a new 4 inch aft pipe section (in my case, from Stainless Specialties), cut the spiral insert to length (drill and tap holes as required to attach the spiral insert to the new aft pipe), have someone weld on the flanges for a v-band clamp, and voila! I did this not because of rattling but because I was tired of the sound of the original mufflers on my old beastie. I'll post pictures in a few minutes, once I find and reduce 'em.

[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.

[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]

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.

[CHANMADD]

Originally Posted by Gus M

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

https://www.google.com/search?q=insi...Nw7dT2Ka4BxpxM

[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.

[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.