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Author Topic: Mac 4 into 1 improvements ??  (Read 1341 times)

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Offline 72_350_FOUR

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Mac 4 into 1 improvements ??
« on: October 03, 2013, 09:15:32 AM »
Has anyone ever tried to improve the mac 4 into 1 to get rid of the "tinny" rattle at higher rpms ??  Didnt find much in the custom search. 
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Offline evanphi

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Re: Mac 4 into 1 improvements ??
« Reply #1 on: October 03, 2013, 10:51:50 AM »
I have the "canister" looking exhaust on mine. I'm getting a Cone Engineering 18" quiet core muffler for it.

« Last Edit: October 03, 2013, 10:54:15 AM by evanphi »
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Offline dave500

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Re: Mac 4 into 1 improvements ??
« Reply #2 on: October 03, 2013, 12:59:41 PM »
take out the baffle and if it looks like the one on the left make it look like the one underneath,the one on the right is there super duper one.


you then wrap the perforated tube with fibreglass insulation wool.
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Offline 72_350_FOUR

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Re: Mac 4 into 1 improvements ??
« Reply #3 on: October 07, 2013, 01:46:50 PM »
Would that require a Jet change ?  I'm running stock sizes right now.
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Offline dave500

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Re: Mac 4 into 1 improvements ??
« Reply #4 on: October 07, 2013, 11:47:59 PM »
no the jets will be ok.
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Offline 72_350_FOUR

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Re: Mac 4 into 1 improvements ??
« Reply #5 on: October 09, 2013, 12:29:31 PM »
Thanks Dave
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Offline jpfrk2001

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Re: Mac 4 into 1 improvements ??
« Reply #6 on: October 09, 2013, 04:01:38 PM »
Just a thought about these exhausts, I have a very similar 4 into 1 header set up like the Mac into a single 2.5" straight dump. No baffles, no nothing. The bike runs really strong and solid. No weird noises. Checked plugs and they look fine. Slight rich mixture signals which explains the smell at first start of the day.

Just saying and throwing that out there. Im positive I have enough back pressure in the system not to burn out my exhaust valves.
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Offline Stev-o

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Re: Mac 4 into 1 improvements ??
« Reply #7 on: October 09, 2013, 08:12:14 PM »
I improved mine by selling it.
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Offline bender01

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Re: Mac 4 into 1 improvements ??
« Reply #8 on: October 09, 2013, 08:25:27 PM »
I posted something about it a few years ago! I cut the inside baffle off. Stuffed a sink strainer/plug in the pipe and packed s/s scrubbies from the dollar store in mine til the noise was better. Put the outer baffle back in to hold my s/s packed concoction in place. Don't over cut the baffle so you can use the outer one as a wedge to hold the sink strainer in. That noise you speak of was the worst sounding rip I never want to hear again and it had to happen from 4-6k! Good luck!
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Offline bwaller

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Re: Mac 4 into 1 improvements ??
« Reply #9 on: October 10, 2013, 04:54:00 AM »
You can use the header and eliminate the mega altogether by making your own midpipe then use a different muffler. I used some SS swimming pool ladder rail and cut/welded to make the pipe, then used a GSXR can. It is quiet but has a nice growl to it.





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Offline 72_350_FOUR

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Re: Mac 4 into 1 improvements ??
« Reply #10 on: October 11, 2013, 09:58:39 AM »
Wow, great looking bike...  I need to learn to weld...  I thought about a different muffler also..
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