Quietening Sidepipes

[AC-460]

Just rebuilding my sidepipes...would like to quieten them down a bit... at present they are 2 1/2 perforated tube inside glass packed 4 inch stainless with 2 inch primary tubes...does anyone know where I can buy FLUTED 2 1/2 tube will this make a difference....
I have also seen spiral flite inside the pipe does this quieten??
Just like to be able to quieten the big block a bit

[xlr8tr]

I'm on the same mission!

I'm not sure what you mean by fluted- is this what you mean?
Classic Chambered Exhaust Inc. - Products

I'm rebuilding my pipes over the next few months, I was going to mount one of the spiral insert units into my tailpipe, have it extend back into the end of the glasspack muffler section, I should be able to get 10-12" worth of spiral insert. I just asked on another post if anyone had done that;
Sidepipe horsepower loss?

[AC-460]

I was wanting to just buy louvered tube....probably 2 1/2 about 30 inches each side

[spookypt]

I've tried a number of different methods to quiten side pipes down including..

- Spiralled baffles
- Perforated tube with wrapped exhaust mat
- Manually operated butterfly's
- Cut down cat converters

They all had verying degrees of effect.

I know with the windsor to quieten it down I went to a perforated tube with woven mat which certainly had a good effect. Its still loud but bearable. Prior to doing that it would clear everyone from the pitsheds within a second of starting it.

I think it has lot to do with the proximity of the pipe exiting next to your right/left ear. My F truck had the pipe to rear and was subtle so we cut 6 feet off the length and exited in front of the RHS wheel and it seems much much louder.

Its a tough ask to get it quiet, but tuff and not restrict flow etc etc.

I'm pretty sure my cobras pipes are due for a rewrap as they are starting to get noisy errr again!

Spookypt

[Zedn]

Turbos are good as natural mufflers

[BMK]

I used the 'Summit' perforated inserts. They are pyramid shaped with preforations that match the internal pipe size so do not add any back pressure or restrictions.

They reduced my first test from 117dB to 110dB

Try sending a PM to Aussie Mike on the Forum he has completed a number of exhausts systems

[Rob. Smith]

Originally Posted by BMK

I used the 'Summit' perforated inserts. They are pyramid shaped with preforations that match the internal pipe size so do not add any back pressure or restrictions.

They reduced my first test from 117dB to 110dB

Try sending a PM to Aussie Mike on the Forum he has completed a number of exhausts systems

7dB reduction is pretty good. I almost bought something similar but couldn't find any info about them; particularly noise reduction. What is the summit part number ? Did you measure from a metre at 45deg from the pipe exit ? was it at idle or drive past ?

[Rob. Smith]

Originally Posted by Rob. Smith

7dB reduction is pretty good. I almost bought something similar but couldn't find any info about them; particularly noise reduction. What is the summit part number ? Did you measure from a metre at 45deg from the pipe exit ? was it at idle or drive past ?

Were these cones the Dynatech Vortex ones /

[mpanten]

I have the spiral inserts and like them a lot. Car still sounds plenty mean when you step on it but you can actually have a conversation when cruising and dont need ear plugs.

[AC-460]

Has anyone played with sliding spiral inserts inside the perforated tube

[kyleb]

I used high flow cats and magnaflow mufflers internally with mine and am very happy with the noise level..
It barks like you would hope when you get on the gas but if you take it easy on the throttle is almost as quiet as the underbody exhaust I had on it.

[Rob. Smith]

I started out with this then I made up a small spiral / auger insert to go inside the 2" perforated pipe inside the 3.5" pipe. I found that it was a bit restrictive so I thought what if I removed the centre pipe. I made up a spiral and slipped that in It made a difference so I machined up some thicker washers and turned them into a spiralinserted that into the 2" perf tube and wrapped it with s.s brillo pads and got this I'm still after a few less decibels. I'm wondering if the 'cones' would help. The whole baffle insert is only about 9" long I tried adding an extra one but it didn't make any difference.

[Rob. Smith]

I tried to submit pics like it is described in the post but I was doing something wrong. I had several other goes. I finally worked out how to put in decent pics so I re-edited the first post. The dribble below are my failed attempts.

[Rob. Smith]

still trying....how do you delete a post ?

[Rob. Smith]

third attempt ! how do you delete stuff-up posts ???

[AC-460]

Thanks Rob good to see what your doing...I was going to try an Auger flight (spiral) that has only a 15mm hole up the centre an 62mm on the outside and slide it the full length of the peforated tube...

[Zedn]

Great post Rob. Will help others.

[BMK]

Rob

Yes the Summit cones are the part you saw.

Seeing your work with the spiral insert and the later spiral coil I think you would have no problem making them up out of a piece of perforated sheet.

The total holes and size of holes add up to the internal pipe surface/opening so there is no restriction.

I spot welded them in and tried it with a meter at 45o at 1100mm. Stationary test.

The drive past was quoted with no evident HP drop. Then opened them and put three deeper spot welds in.

I have heard owners have used one at each end of the muffler for better results.

[Rob. Smith]

Thanks Bernie, That's what I wanted to hear. I think I've got some perforated sheet left. I'll have a go at making a pair and let you know. One little problem though. I've had these pipes ceramic coated inside and out so I won't be doing any welding on them.
Later down the list I'll build another set of pipes if the cone inserts have any decent effect.

[BMK]

Rob just one small hole self taper secure in place or a small spot weld underneath. If they are effective, then heavy deep weld in.