2-11 Exhaust silencer - Track Limit 95DB - LotusTalk - The Lotus Cars Community
 
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post #1 of 5 (permalink) Old 09-15-2016, 06:13 AM Thread Starter
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2-11 Exhaust silencer - Track Limit 95DB

Hello good people.

Any idea on how to lower the noise from the exhaust, most tracks in Sweden & Denmark have a limit on 95db (for some boring reason, don't ask why.)

The problem is when driving at 6000+ RPM the car is around 110-120db and we are being giving the black flag

At the moment we have in most cases resolved this by adding a small 90 pipe to point the sound away from the tracks microphone.


Does an exhaust muffler like this one help?
3.5"4"4.5" Exhaust Muffler Exhaust Tip Removable Silencer for Acura Honda Ford | eBay

Any suggest that can help us without costing on performances or risking to damage the engine are most welcome
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Last edited by Clausft; 09-15-2016 at 06:24 AM.
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post #2 of 5 (permalink) Old 09-15-2016, 06:44 AM
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BOE Featherweight Exhaust ? BOE Fabrication

I've used the ST-5 muffler at Laguna Seca for a 92db day and it worked.

BOE is the vendor but may not be optimal for your use given your location.

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post #3 of 5 (permalink) Old 09-15-2016, 01:11 PM
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I have the same problem .. I had a new muffler built here in NZ that was supposed to be under 95dba ... but unfortunately not ... so looking to do something as per attached picture .
Approx 300mm long and 5" diameter
A couple of other things I have heard of but not tried ...
Have the tail pipe facing toward the ground . Apparently the sound waves disperse better if they hit the ground.
Drill some small holes in the tailpipe and thread safety wire across the pipe 4-6 times .This helps break up the sound and drop the dba.
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post #4 of 5 (permalink) Old 09-16-2016, 12:57 AM Thread Starter
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Drill some small holes in the tailpipe and thread safety wire across the pipe 4-6 times .This helps break up the sound and drop the dba.
Home | Decibel Devil has been known to work
Thanks, will order the DecibelDevil Noise reducer and let you know the result


Jack, thanks for the feedback will take a look at it if the DecibelDevil doesn't work =)
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post #5 of 5 (permalink) Old 09-16-2016, 05:57 AM
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I ran across these photos of the muffler setup used at Laguna (92db weekend) . ST-5 plus redirect pipe for extra measure -- sound station located 50 ft off the track surface on the right.
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