3" exhaust noise limits


Jack24

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Sep 13, 2011
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I'm thinking of getting a 3" exhaust made up before it gets mapped again and I was wondering would it pass the noise limits for track use if it is heavily silenced? I've seen a few and they have been stupid loud! I have a twinloop in the garage that I could change with the back box if it is to much i suppose
 


grahamb

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Nov 26, 2011
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Should be cool , I have a 5zigen pro racer 3inch with decat and 4branch and it's only slightly over , bolt on silencer with the right exhaust should be okay
I emphasise the "right exhaust" tough
 


KieranEG6

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Can be done. Try to incorperate at least two 14" or 16" long silencers into the center section an a decent back box.

If it still doesn't cut it then juts make sure you have a 3"-2.5" clamp on tail pipe reducer. Will take out a tone of the drone with minimal flow restrictions.

Im still in the proccess of making my 3" system. At first I was going to make it full 3" then reduce it into a 2.5" back box but after playing about with the 3" back box Iv just made for my pulsar I was amazed by how much difference a 2.5" reducer made to the drone and noise.

I would say its do able. Well im bloody hopping so! haha

There seems to be alot of controversey over the whole 3" system on N/A thing, but there are tons of proven gains even on b18's. The guys on Honda-tech sware by 3" systems and have loads of dyno readings to back it up.
 


Jack24

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The guys on k20a.org swear by the 3 inch system as well. O.k i'll go for 3 inch pipework and a 2.5 in tip and see if thats o.k. Its a good job i asked as I would have only request 1 silencer in the centre section. Thanks again guys
 


KieranEG6

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You might get away with one decent silencer in the center.

I looked into it a few months back and apparently when it comes to straight through perforated designs, two smaller silencers will be quieter than one bigger one, as the majority of the work is done in the first foot(12") of the box.

If you have the money Vibrant make a good few different universal box's that are supposed to be good quallity. Im just going to make it from what I can get through my work. Mine will be two 14"x5" center box's and a 14"x6" back box.
 


alan168

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Jan 25, 2008
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Mine is 3" decat an I think 17" silencer in b pipe
As long as I could get into the b pipe anyway

Read 98 on launch control at Cadwell last week
 




Jack24

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Sep 13, 2011
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That sounds promising. Solid fabrications is a bit far away for me but I've heard good reports about JP fabrications in warrington so i'm going to try there
 


EK4 Luke

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Jan 17, 2012
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alan at solid fabrications's good he did my 2.5 inch system which is pretty much silent got a 30 inch middle box though :)
 


689R

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Feb 29, 2008
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Alex's PY K20 EK9 has a 3inch exhaust done custom which is just the right volume. Doesnt drone and is not obnoxiously loud. He has obviously been on knockhill but I am not sure if they have a DB limit.
 


tama666

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once had the SK2 3" exhaust, with silencer, and it was still to loud.
SK2 was removed, and custom 3" installed, test pipe as well, then installed an adjustable tip to angle the noise to the ground as well as pointing away from the track microphone. I adjust pending on mic location per-track day.

..it works well.
 

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Jack24

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Sep 13, 2011
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That's a clever idea. I'll speak to the people that are going to make it and see what they can do
 


solid-fab

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Feb 12, 2009
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A couple things you can do but I can normally use non straight through rear box if I get a customer needing the car quieter.
 





solid-fab

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Feb 12, 2009
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with a long centre silencer and a decent sized back box it should be ok for track use.
 



rosey_ej9

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Aug 30, 2009
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I had 3'' from manifold back on my high comp B18, didnt ever get to drive it hard but it was LOUD. Could be possible with silencers though
 


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