CBR650R Hollowed stock muffler

[Kevin]

I’m debating on whether or not to knock out the cat while I’m in there. Worried though that with half a baffle and no cat it will be too loud. My last bike was a Harley with Vance and Hines which were basically straight pipes and after a day of riding my ears were ringing for a few hours.

 

[Enrico]

I’m debating on whether or not to knock out the cat while I’m in there. Worried though that with half a baffle and no cat it will be too loud. My last bike was a Harley with Vance and Hines which were basically straight pipes and after a day of riding my ears were ringing for a few hours.

Not a good idea, you don't want to end up with Tinnitus !

 

[Kevin]

Decided against knocking out the cat. More for backpressure issues than anything. The baffling is quite intrusive so it should make a nice improvement on the sound. Noise played a role in the decision too. I like to ride to work but I leave at 5:15am and always felt bad dragging the Harley out that early.

When I went to the HD dealer near me to price out the baffles for the V&H pipes the parts guy looked at me and just asked “why?” When I explained what time I leave he just said “F*** your neighbours.” That pretty well summed up my experiences at the dealer. Just a bunch of guys that dress up on the weekends to play bad-ass.

 

[GPJake]

When I explained what time I leave he just said “F*** your neighbours.” That pretty well summed up my experiences at the dealer.

I don't understand that attitude.

I appreciate loud harleys for what they are. I don't have any desire to own one, but I enjoy when they ride by.

But to be a perpetual jerk to the people you have to live next to for.... Reasons? I just don't get it.

 

[Kevin]

But to be a perpetual jerk to the people you have to live next to for.... Reasons? I just don't get it.

That makes two of us.

Hollowed out the breadbox today. What a pain cutting it out, if it weren’t stainless a torch would have made that job a breeze. Anyways got it all welded back together and plan on throwing it back in on the weekend. Can’t wait to hear the difference!

 

[JH09]

interested to see and hear the results as well. did you take a video of the "before"? thx

 

[Enrico]

I like the sound of a 'louder than stock' exhaust, but I wouldn't want one that was so loud my ears were ringing for hours after I stopped riding (that to me seems a sign that your hearing is being damaged ) I fitted road legal Fuel exhausts to a Yamaha bulldog that sounded good but not too loud in my opinion.

 

[Kevin]

interested to see and hear the results as well. did you take a video of the "before"? thx

I should have but didn’t. When I had the pipes almost off I realized I should have done a before and after and I should have taken pics of the disassembly for others to use as a reference.

Unless you have access to a welder, 308 wire, a grinder and a die grinder with carbide bits this wouldn’t be a very economical job. It took about 3 hours to cut it open, hollow it out and weld it back together and ballpark 1.5 hours for removal and reinstall. All in all not terrible if you do it yourself.

 

[Kevin]

Finally found some time this morning to put the pipes back on and wow what a difference. It is louder than I was expecting but not obnoxiously loud. I am very happy I went through with it. Now it needs to stop snowing so I can hear it at 12,000rpm!

 

[Kevin]

First ride with the hollowed muffler yesterday and I couldn’t be happier. It definitely opens up the sound of the bike without being too loud. Personally I think it’s the perfect volume and it just sounds so much more aggressive. If you have the tools and know-how to do it yourself it’s a no brainer.

 

[CaptainObvious]

First ride with the hollowed muffler yesterday and I couldn’t be happier. It definitely opens up the sound of the bike without being too loud. Personally I think it’s the perfect volume and it just sounds so much more aggressive. If you have the tools and know-how to do it yourself it’s a no brainer.

Totally agree. Glad you're happy with it.

 

[Chyurri]

First ride with the hollowed muffler yesterday and I couldn’t be happier. It definitely opens up the sound of the bike without being too loud. Personally I think it’s the perfect volume and it just sounds so much more aggressive. If you have the tools and know-how to do it yourself it’s a no brainer.

Where are you located? Interested to hear this in person.

 

[Kevin]

Where are you located? Interested to hear this in person.

Hamilton area, Ontario.

 

[Bindir Dundat]

Post some video pls.

 

[darby_07]

Post some video pls.

Go to the first page in this thread there's an idle and rev video.

 

[daffnz51]

Hi all
I'm sorry if this has been covered but I can't find it anywhere so here I go..

Has anyone removed the cat (knocked or drilled it out) and pretty well left the baffles in place??
Seems like a good option to increase flow in the exhaust and increase the sound while hopeing that the remaining baffles will be enough to maintain a sound which is not obnoxious.
Planning to do this and want to know if anyone can advise for or against.
Model 2022 CB650R

Many Thanks 👍

 

[miweber929]

Hi all
I'm sorry if this has been covered but I can't find it anywhere so here I go..

Has anyone removed the cat (knocked or drilled it out) and pretty well left the baffles in place??
Seems like a good option to increase flow in the exhaust and increase the sound while hopeing that the remaining baffles will be enough to maintain a sound which is not obnoxious.
Planning to do this and want to know if anyone can advise for or against.
Model 2022 CB650R

Many Thanks 👍

If memory serves, the cat isn’t easy to get to because it’s deep inside the pipe and it was a bitch to get free because it was welded very well in there. Also if I remember right, they ended up having to cut the collector box open and welded back up to hollow everything out of it.

It’s here somewhere, a couple have done it and I’ve seen the pictures, but yeah, initial searches didn’t find it. EDIT: it’s actually this thread.

So if what described sounds doable to you, go for it. If not, well, at least you know the why it’s not easy.

 

[Enrico]

Hi all
I'm sorry if this has been covered but I can't find it anywhere so here I go..

Has anyone removed the cat (knocked or drilled it out) and pretty well left the baffles in place??
Seems like a good option to increase flow in the exhaust and increase the sound while hopeing that the remaining baffles will be enough to maintain a sound which is not obnoxious.
Planning to do this and want to know if anyone can advise for or against.
Model 2022 CB650R

Many Thanks 👍

Just leave it alone or fit a proper aftermarket exhaust system that suits you better.

 

[Vini.Duarte]

Hey everyone!

I recently picked up a 2024 CBR650R stock exhaust from a crashed bike and I am planning to do the hollow mod on it before fitting it to my 2014 CB650F.

Before I crack it open I wanted to check with you guys, has anyone here already opened a 2024 muffler? The shape looks quite different from the older models, more rounded and organic compared to the rectangular shape of the 2019-2021.

A few things I am trying to confirm:

1. Is the internal layout still the same — CAT near the inlet, 2 baffles, basalt wool packing?
2. The cut line on mine looks like a vertical center seam instead of a bottom horizontal cut like the older ones — is that correct?
3. The 2024 has 2 O2 sensor holes — I am planning to use my CB650F sensor in the main hole and seal the second one with a M18x1.5 bolt. Does that sound right?

I will document everything with photos and post the results here so it can help others.

Thanks