How to make a reverse cone exhaust quieter?

12017 Views 30 Replies 9 Participants Last post by Farmer_John, Oct 3, 2020

pbergmans

Discussion Starter · Sep 22, 2020

Hi all...I recently installed a reverse cone exhaust on my 2017 Yamaha SR400. When I fired it up for the first time I immediately realized that it's too loud. I'm quite sure my neighbors are going to hate me for this mod. My question is, how can I make this exhaust more quiet? I've seen some videos of people adding baffles to their exhaust but in these examples the person had a (more or less) straight pipe and they were able to drill a hole in the pipe to secure the baffle. When I look at my reverse cone, I don't really understand how I can do that. I'd also like to add that I'm a newbie at making modifications and I don't have any fabrication skills. So, if you have a suggestion for me, it'd be best if I could buy something that's semi-easy to install. Here is an image of my exhaust...

Thanks in advance.

See less See more

Save

1 - 4 of 31 Posts

jcw

· #7 · Sep 22, 2020 (Edited)

Anything that you can stick in there that reduces the outlet size will reduce the sound.
Usually baffles are a smaller diameter perforated tube with end caps that fit inside the exhaust and mount with a set screw from the outside.

Here's one as an example without the perforated core

https://smyperformance.com/pub/media/catalog/product/cache/17d8916955d56ab7b7afc147696bff72/p/b/pb609b-ins02.jpg

This is likely something like what you saw.

The set screw is there so it can be removable. If you don't mind it being permanently installed, a couple spot welds could be placed inside the exhaust to hold it in place.
You could always grind out the spot welds if you needed to remove it.

I would get a very accurate measurement of the ID of the muffler, give the dimensions to someone that could weld up an insert like that. test fit it to see if you like the sound and spot weld it.

See less See more

Save

Reactions: 2

jcw

· #8 · Sep 22, 2020

This is even something if you are interested in and have some extra $$$ you could buy a welder and learn to do yourself if so inclined...

Save

jcw

· #15 · Sep 22, 2020

pbergmans said:
@jcw - thanks for the useful information. Am I right in thinking that your comment "and mount with a set screw from the outside" is not easily possible since I have a cone? Or, do I disassemble my exhaust (e.g. remove rivets) and replace the core? Do baffles exist that have a different mounting mechanism other than an external screw? Or, is welding it in my only solution?

First thing is maybe check with the company you bought the exhaust from. Sometimes they will sell an insert to reduce db.
If this was an internet special, then u are stuck measuring and searching for your own insert.
You've pretty much listed your options in your post.
#1 find or fab an insert and figure a way to secure it in place
#2 try to modify your muffler
#3 go back to stock.

I would try 1. If you can't find an insert, I might be willing to help fabbing one up...
Strictly for offroad use...

Save

jcw

· #18 · Sep 22, 2020 (Edited)

This is the insert in my gsxr leo vince slip on. For an example. Set screw goes in at the bottom. This came from the manufacturer.

See less See more

Save

Reactions: 1

1 - 4 of 31 Posts

This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.

Top Contributors this Month