Muffler design for race car

@rishabh1234-Oi9Xdl • Oct 26, 2024

Oct 26, 2024

1.3K

i am working on a project of making race car for some international competition . According to rules , the noise level should be less than 110 db . I have designed two absorptive mufflers but none of them was able to reduce the sound level to that limit. So, now i am thinking of designing a reactive muffler but wont have sufficient knowledge. So, anyone having any knowledge or prior experience regarding this please help me . its urgent ,we have to complete it within this month. Regarding engine , we are using honda cbr600rr engine .

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Ankita Katdare

@abrakadabra • Oct 13, 2014

Tagging #-Link-Snipped-# #-Link-Snipped-# #-Link-Snipped-# #-Link-Snipped-# #-Link-Snipped-# #-Link-Snipped-# #-Link-Snipped-#
Ramani Aswath

@ramani-VR4O43 • Oct 13, 2014

The only personal mechanised transport I have driven (?) is an old Humber bicycle. This is way off my radar.
Any attenuation (sound or light) tends to be frequency specific. Bose systems sell a noise suppressing head phone, which is a single user device. It may be possible to device something that can do this to a car exhaust.

Some basic design principles are available.
here are two sources offered for what they are worth as I am not competent to judge their value.
#-Link-Snipped-#
Shashank Moghe

@shashank-94ap1q • Oct 14, 2014

Well, #-Link-Snipped-# , that is an awesome project. As #-Link-Snipped-# said, sounds in an automobile are frequency specific. Since you say the designed mufflers are not able to suppress the noise below 110 dB, there is a very strong chance that there is some particular component which might be producing that noise, and that needs your attention. May be you can take care of its sound level and you should be good to go! My point is: troubleshooting to identify which component/noise in particular is the culprit and taking care of it.

For this, I had a Matlab code written in Grad school which takes a sound input as an excel file (easy to make from a sound input) and does the Fourier transform on it to give the frequency components of the sound file. This code might help you identify the frequencies with highest amplitudes (I think it is scaled to show amplitude in dB, even if not, it is a very easy conversion from V to dB). Looking at those plots you might get an idea to find out which component needs your attention.

Note: This is not the kind of solution you asked for. I am just contributing my 2 cents, as otherwise, I have no experience of Muffler design with which I can help you. I will share the file with you after I get home today.
Rishabh1234

@rishabh1234-Oi9Xdl • Oct 14, 2014

#-Link-Snipped-# sir , it would be of great help if u share the code.
lal

@lal-R60Xjx • Oct 14, 2014

A.V.Ramani
Bose systems sell a noise suppressing head phone, which is a single user device. It may be possible to device something that can do this to a car exhaust.[/url]
That would be to record and invert the phase of muffler's sound and reproduce on a loudspeaker with zero time lag.
Shashank Moghe

@shashank-94ap1q • Oct 14, 2014

Rishabh1234
#-Link-Snipped-# sir , it would be of great help if u share the code.
Sir 😁 That was uncalled for 😀
Rishabh1234

@rishabh1234-Oi9Xdl • Oct 14, 2014

actually i am habituated of calling sir here in collage.
Shashank Moghe

@shashank-94ap1q • Oct 14, 2014

Never mind, don't call me that 😀 I feel older than I am 😀
Rishabh1234

@rishabh1234-Oi9Xdl • Oct 15, 2014

haha ok. can u please upload the code soon. its a little urgent
Shashank Moghe

@shashank-94ap1q • Oct 15, 2014

I will message you the code. Wont share it here. I am finding it, should be in your mailbox in 12 hours.
Rishabh1234

@rishabh1234-Oi9Xdl • Oct 15, 2014

ok thanks
Suman Kumar Jha

@suman-kumar-mxicIF • Oct 28, 2014

If u are making race car for sae supra.......Then u can use some external support for reducing the unwanted noise..........
Rishabh1234

@rishabh1234-Oi9Xdl • Oct 29, 2014

i am making it for FSAE. what kind of external source are you talking about
Suman Kumar Jha

@suman-kumar-mxicIF • Oct 29, 2014

micro system for reducing the noise of muffler........
Rishabh1234

@rishabh1234-Oi9Xdl • Oct 29, 2014

i think its against the rule of fsae competition.
Suman Kumar Jha

@suman-kumar-mxicIF • Oct 30, 2014

Since I didnt read the FSAE rule book so i have no idea what is against rule...............Is it mention in rolebook that in car micro system is not allowed.
Rishabh1234

@rishabh1234-Oi9Xdl • Oct 30, 2014

what type of micro systems are u talking about
Suman Kumar Jha

@suman-kumar-mxicIF • Oct 30, 2014

First tell me have u read the rule book of FSAE..............is it mention some where in book that u cant use microsysytem.........
Suman Kumar Jha

@suman-kumar-mxicIF • Oct 30, 2014

rule book of FSAE.........
Suman Kumar Jha

@suman-kumar-mxicIF • Oct 30, 2014

Read this rule book and work according to rule.............
Rishabh1234

@rishabh1234-Oi9Xdl • Oct 30, 2014

yeah i have read it. it is not explicitly written to avoid the use microsystems .
Suman Kumar Jha

@suman-kumar-mxicIF • Oct 31, 2014

I have one journal in which these micro system is discussed..........but the PDF size is 22 MB.........it getting problem to upload.......give your email I will mail u
Rishabh1234

@rishabh1234-Oi9Xdl • Oct 31, 2014

Spoiler: My Email
Kaustubh Katdare

@thebigk • Nov 1, 2014

Suman Jha
I have one journal in which these micro system is discussed..........but the PDF size is 22 MB.........it getting problem to upload.......give your email I will mail u
Why not upload the file to the 'downloads' section? Others will be able to download and benefit from it. 😀
Suman Kumar Jha

@suman-kumar-mxicIF • Nov 1, 2014

I upload the journal on download section u can #-Link-Snipped-#
Rishabh1234

@rishabh1234-Oi9Xdl • Nov 1, 2014

what is the name of the file? i cant find it
Suman Kumar Jha

@suman-kumar-mxicIF • Nov 2, 2014

microsystem for automobile......
Rishabh1234

@rishabh1234-Oi9Xdl • Nov 3, 2014

i think they have removed your file from here.
please mail it.
Suman Kumar Jha

@suman-kumar-mxicIF • Nov 3, 2014

Yes since that was a journal so they remove...........
Suman Kumar Jha

@suman-kumar-mxicIF • Nov 3, 2014

The file size of the ebook is more than 25 MB.....I cant mail to u.......
Suman Kumar Jha

@suman-kumar-mxicIF • Nov 3, 2014

The file size of the ebook is more than 25 MB.....I cant mail to u.......
Rishabh1234

@rishabh1234-Oi9Xdl • Nov 3, 2014

you can upload it on any file sharing site. i think scribd would be best.
Suman Kumar Jha

@suman-kumar-mxicIF • Nov 4, 2014

ok I am trying..........
Rishabh1234

@rishabh1234-Oi9Xdl • Nov 5, 2014

have u done it ?
Suman Kumar Jha

@suman-kumar-mxicIF • Nov 5, 2014

no I am going to......
Rishabh1234

@rishabh1234-Oi9Xdl • Nov 10, 2014

please post the download link here when you are done uploading it .
Suman Kumar Jha

@suman-kumar-mxicIF • Nov 11, 2014

okkkk...........