Author Topic: Baffled by Mac 4-1  (Read 3620 times)

0 Members and 1 Guest are viewing this topic.

Offline Tom Burns

  • Full Member
  • *
  • Posts: 12
Baffled by Mac 4-1
« on: April 15, 2014, 07:59:12 AM »
I have a 77 CB550K with Mac 4-1 exhaust with the original Mac baffle. It's too quiet. I came across this performance competition baffle that evidently has more drilled holes:
 http://m.ebay.com/itm?itemId=171246465640

Does anyone have experience with the sound using this replacement baffle. I've read a lot of threads about modified Mac exhaust and most say they sound like crap. I'd rather stay quiet than be loud and not proud.


77' CB550K
98 VTR1000

Offline Tugboat

  • Puppet
  • Master
  • *****
  • Posts: 1,778
  • '75 CB750K + '67 CL90 + '71 CT90
    • PseudoMoto
Re: Baffled by Mac 4-1
« Reply #1 on: April 15, 2014, 08:50:09 AM »
My Mac muffler on my 750F has the baffled drilled out 6-8 holes. Sounds badass IMO!
If it's worth doing, it's worth doing twice.

Offline Scott S

  • Global Moderator
  • Really Old Timer ...
  • *****
  • Posts: 8,232
Re: Baffled by Mac 4-1
« Reply #2 on: April 15, 2014, 11:27:21 AM »
 If you're referring to the bike in the picture, that's not a MAC header. Looks like maybe an F header on a K bike with a replacement muffler, which could be a MAC.
 MAC sells more than one baffle, depending on whether you have a canister style muffler or a cone style.  I'm not sure either would fit that muffler.
'71 CB500 K0
'17 Triumph Street Scrambler
'81 Yamaha XS650

Offline Geeto67

  • A grumpy
  • Old Timer
  • ******
  • Posts: 2,823
Re: Baffled by Mac 4-1
« Reply #3 on: April 15, 2014, 12:20:10 PM »
I have a 77 CB550K with Mac 4-1 exhaust with the original Mac baffle. It's too quiet.

....said no one ever until you came along. Do you not like your neighbors? Or are you tired of law enforcement ignoring you? Or do you not feel like you are "saved" unless it is by a loud pipe?

Remember, every awful loud motorcycle is one more reason for the motorcycle public to hate us.

That being said here is what you do: Get a drill and a hole saw. Start by drilling holes in your baffle (after you removed it from your bike of course). Do it one at a time and test it each time by reinstalling it on the bike until it is loud enough. Cost = 0.


Maintenance Matters Most

Offline EricHa

  • Enthusiast
  • **
  • Posts: 102
Re: Baffled by Mac 4-1
« Reply #4 on: April 15, 2014, 01:44:15 PM »
I have a 77 CB550K with Mac 4-1 exhaust with the original Mac baffle. It's too quiet.

....said no one ever until you came along. Do you not like your neighbors? Or are you tired of law enforcement ignoring you? Or do you not feel like you are "saved" unless it is by a loud pipe?

Remember, every awful loud motorcycle is one more reason for the motorcycle public to hate us.

 ::)

Hi Tom. That baffle will be significantly throatier than a stock Mac, and would be ptretty loud when you get all over it. If you go easy on the throttle you should be ok with it about anywhere. Plus, if you don't like the sound, throw your unmolested OEM baffle back in. Bottom line, the way your bike sounds is between you, your neighbors and the police.  Good luck.
1975 Honda CB550K1
1976 Honda CB750K6
1977 Kawasaki KZ900A5

Offline InTheStreet

  • Ha, you let me be a
  • Full Member
  • *
  • Posts: 87
  • When in doubt, flounder about.
Re: Baffled by Mac 4-1
« Reply #5 on: April 16, 2014, 03:58:46 AM »
I drilled a few holes on the internal sections of the baffles that run parallel to the exhaust.  I did it a few holes at a time and the sound got minimally louder as I went until I found a sound that was pleasing to me.
1975 CB550K1
1980 CB650C (parting out)
1980 GL1100 (sold and missed)

Offline Tom Burns

  • Full Member
  • *
  • Posts: 12
Re: Baffled by Mac 4-1
« Reply #6 on: April 16, 2014, 10:40:22 AM »
Thanks guys, I guess that may be an F header.  The exhaust came with the bike. I just know the header wasn't original.
I do not want to make it extremely loud.  The volume is perfect in the high range, a little too quiet in the mid and nearly silent idling. A moderate volume increase should be fine with the cops and neighbors since I only open it up out in the middle of nowhere.....ok, I'm lying. Plus, I like to have enough volume to be able to make oblivious drivers aware of my presence by popping  the throttle.
I 'spoze I'll just drill ant test it till the volume suffices.
77' CB550K
98 VTR1000

Offline Geeto67

  • A grumpy
  • Old Timer
  • ******
  • Posts: 2,823
Re: Baffled by Mac 4-1
« Reply #7 on: April 16, 2014, 11:05:54 AM »
I like to have enough volume to be able to make oblivious drivers aware of my presence by popping  the throttle.

not always a good thing...or have you not yet encountered the driver who turns their steering wheel the same direction as their head when they are startled.

A louder horn (like a set of FIAMMs) does the same thing but then you can be selective about it and it doesn't annoy anybody with noise pollution.
Maintenance Matters Most

Offline Tom Burns

  • Full Member
  • *
  • Posts: 12
Re: Baffled by Mac 4-1
« Reply #8 on: April 16, 2014, 11:43:19 AM »
Let's just say there is a time and a place for everything. I was referring to times like being stopped at an intersection and a drivers head movements indicate they are about to do something stupid. Otherwise I am that ass hole that lays on the horn and lives to see another day.
77' CB550K
98 VTR1000

Offline Tom Burns

  • Full Member
  • *
  • Posts: 12
Re: Baffled by Mac 4-1
« Reply #9 on: April 16, 2014, 11:53:32 AM »
Plus I find a little throttle pop to be less annoying than a horn,  just as effective in some situations and less likely to provoke an ass hole to drive up alongside me so he can flip me off and scream " I see you."
77' CB550K
98 VTR1000

Offline Geeto67

  • A grumpy
  • Old Timer
  • ******
  • Posts: 2,823
Re: Baffled by Mac 4-1
« Reply #10 on: April 16, 2014, 12:21:56 PM »
Plus I find a little throttle pop to be less annoying than a horn,  just as effective in some situations and less likely to provoke an ass hole to drive up alongside me so he can flip me off and scream " I see you."

has that really happened? If so you can take solice in the fact that that person has way more issues in his life that don't relate to you.

I have had all manner of things yelled at me while riding. I don't take it personally, I rarely hear what they are as I float past and I just assume they would rather be where I am than I would be where they are. The best one though when when I used to lane split in the city, I used to get "you're cheating" often. Always made me smile.

But back to your muffler as a warning system - the science doesn't support it. The majority of a motorcycles sounds are behind the bike because that is where the mufffler opening is. Unless you are ungodly harlye loud most new cars aren't going to hear you even if you are right on top of them. You can't hear any bike from the side or behind (except my ducati and my ironhead more on that in a minute) from inside my wife's audi - not the kerker race baffle cb750s, not the kerker race baffle equipped gs750, not any friends bikes with micron cans or supertrapps.

engine noise is not a deterrent to anything, full stop. Even in situations where they can hear you it poses as much as danger as it does help you (triggering road rage, startling drivers). Loud pipes do not offer any more safety in this hobby - proper training and gear does.

The point of this conversation is if you are going to own a loud bike, own up to it and it's consequences. I do. I own two bikes with open pipes the ironhead HD and a ducati sport 1000. I do not pretend them being loud offers me any safety, and I get called arsehole by other motorcyclists and I own it, I am an arsehole.  The ducati I had set up as a track bike but then came to my senses and realized I wasn't going to actually track it so it is tuned and set up for a set of "for race use only" open megaphones. to make it quieter I would have to retune the bike and spend money on it. The HD came with the open pipes and I have hated them since day 1. In fact I just put baffles in the pipes because it is uselessly loud. I may actually put a factory XLCH highpipe and muffler on it because it needs to calm down.

I am a big fan of informed decision making. I have supplied you to the best of my knoweldge as much that surronds this decision. The rest of the decision is up to you. I would feel remiss if I didn't mention that loud pipes do not save anything and it might turn you into a social outcast amoung a group that is already some what of a social outcast. The fact that you want to argue your point that there is a situation where a loud pipe might actually save something indicates you need all the information you can get because it just isn't true. the science doesn't support it, the stats don't support it, it's a myth. let it go.
Maintenance Matters Most

Offline Tom Burns

  • Full Member
  • *
  • Posts: 12
Re: Baffled by Mac 4-1
« Reply #11 on: April 16, 2014, 12:29:08 PM »
I've had a beer bottle thrown at me because I beeped my horn at a car. Everyone has their own means and methods. Mine have served me well for many years and many miles.
I own the fact I want a loud but not too intrusive sound for the sound alone.
77' CB550K
98 VTR1000

Offline Tom Burns

  • Full Member
  • *
  • Posts: 12
Re: Baffled by Mac 4-1
« Reply #12 on: April 16, 2014, 12:33:50 PM »
It may have something to do with where one lives.  I live in Chicago where there's plenty of ass holes looking for a reason to unload rage.
77' CB550K
98 VTR1000

Offline Geeto67

  • A grumpy
  • Old Timer
  • ******
  • Posts: 2,823
Re: Baffled by Mac 4-1
« Reply #13 on: April 16, 2014, 12:58:12 PM »
I have most of my years of riding in NYC, one of the most inhospitable places to ride a motorcycle. I've had people try to hit me with their cars plenty of times for plenty of reasons. the entire city is one large ball of rage.

the fact that you say this --> Everyone has their own means and methods. Mine have served me well for many years and many miles

means you are going to continue to ride under a falsehood. it's your business to do so but it doesn't stack the odds in your favor. Hopefully you ride with good gear and good training. just try not to tell people you believe loud pipes save lives - its akin to telling people you believe in the easter bunny as an adult.
Maintenance Matters Most

Offline Tom Burns

  • Full Member
  • *
  • Posts: 12
Re: Baffled by Mac 4-1
« Reply #14 on: April 16, 2014, 01:08:58 PM »
No I don't subscribe to the "loud pipes save lives" fallacy and am well aware that people swerve in the direction of distraction/ startle. On the open road loud pipes may even prevent me from hearing something. But I will not be persuaded that a little throttle pop at a 4 way stop where a driver on a cross street has not looked my way gets better results for me. Thanks
77' CB550K
98 VTR1000

Offline Tom Burns

  • Full Member
  • *
  • Posts: 12
Re: Baffled by Mac 4-1
« Reply #15 on: April 19, 2014, 08:33:04 PM »
Thanks for the suggestions. I made a little Swiss cheese out of the baffle and like the results a lot....sounds good and not too loud.  I was planning on doing a single layer of glass packing to filter out some of the high frequency but this type of baffle is not a good candidate for that. In the future I may cut the baffle tubes and make a straight pass thru baffle out of perforated sheet or screening and glass wrap it.  But I'm happy for now.
77' CB550K
98 VTR1000

Offline cb650PK

  • Hot Shot
  • ***
  • Posts: 258
Re: Baffled by Mac 4-1
« Reply #16 on: April 20, 2014, 05:37:09 AM »
Mac sold and may still sell competition baffle that is straight through design. Kind of like on a Kerker that Gheeto had on one of his bikes:)
Here http://www.ebay.com/itm/like/231068372687?lpid=82
Mac sells them directly for like $45 but they don't have pic of it on there web site.
« Last Edit: April 20, 2014, 05:44:27 AM by cb650PK »
S CB750 na vecne casy a nikdy jinak.

Offline Tom Burns

  • Full Member
  • *
  • Posts: 12
Re: Baffled by Mac 4-1
« Reply #17 on: April 20, 2014, 09:56:50 AM »
Yes, I've seen these. I don't know if it will fit in my can though.
77' CB550K
98 VTR1000

Offline Tom Burns

  • Full Member
  • *
  • Posts: 12
Re: Baffled by Mac 4-1
« Reply #18 on: April 20, 2014, 10:01:40 AM »
I'll pull my baffle out, measure it and compare it.
77' CB550K
98 VTR1000