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CVO Technical => Intake/Exhaust/ECM => Topic started by: North Star on March 03, 2018, 07:05:54 PM

Title: Feedback on S&S MK45 mufflers?
Post by: North Star on March 03, 2018, 07:05:54 PM
Buddy of mine got a set- haven't heard them yet, but he said Fuel Moto said they perform as good as the Crushers.

I've run Rineharts, 2" Fullsac baffles in stock cans, and now have the Crushers on. I like them because they are top performers, and although my bike was tuned with the Fullsacs, they must be similar because the bike runs just as well.

I like the sound of the Crushers, but at times I'm not a fan of the jack hammering sound. Plus, I wouldn't mind a change for the hell of it.

Does anyone run them on their CVO's? I just want to make they don't lose any performance/low end torque like so many other slip ons. If they really do perform as well as the Crushers or Fullsacs, I'll give them a try.

Particularly looking forward to any replies from our tuners to see their experience on tuning with these mufflers.

Title: Re: Feedback on S&S MK45 mufflers?
Post by: hd-dude on March 03, 2018, 11:20:47 PM
I have tuned both, they both work well. The 45's are louder than the crushers and have a deeper bass note. You can add the baffle (they are included but not installed) to the 45's that quiets them down and also lessens the bass note a bit.
Title: Re: Feedback on S&S MK45 mufflers?
Post by: North Star on March 04, 2018, 01:15:31 AM
Thanks for that info. Louder and more bass sounds good to me. One of the reasons I like them is because of the db killers. Would take a couple minutes to slip them in when going on a trip. Makes it simple to change up the sound.
Title: Re: Feedback on S&S MK45 mufflers?
Post by: North Star on March 04, 2018, 03:57:04 PM
Any idea what size baffles are in them?
Title: Re: Feedback on S&S MK45 mufflers?
Post by: North Star on March 06, 2018, 01:24:31 PM
I called S&S today and spoke with Tech Support. The guy I spoke to didn't know what size baffles were in them, and said his "exhaust guy" wasn't in today. Pretty commonly asked question I thought- figured he could have gotten me the answer but apparently not.

Guess I'll try to call another day.
Title: Re: Feedback on S&S MK45 mufflers?
Post by: hd-dude on March 06, 2018, 02:36:24 PM
I have not measured them but i believe they are 2.25". They are a perforated baffle. The DB reducer is an 8" long, 2" louvered baffle that inserts into the end of the pipe.
Title: Re: Feedback on S&S MK45 mufflers?
Post by: North Star on March 06, 2018, 09:46:01 PM
Well it may not be as simple as I make it sound, but if they have 2.25" baffles I gotta figure they would hurt low end torque as compared to my Crushers with 2" baffles. That's why I had to loose my Rineharts because during my tune post 113 build, my tuner said they were hurting low end. Sure I suppose once the db killers are inserted and the cores narrow to 2" at the outlet ends, it would get some backpressure back, but I don't want to have to run the inserts all the time just to have optimized performance if I don't want to.

I realize there is probably more to performance than strictly the bigger the baffle, the less backpressure equals loss of low end torque- maybe a bigger baffle can work just as well depending on length, design, etc, but it seems to me at this point I'm not convinced they are at least equal to my Crushers performance wise.
Title: Re: Feedback on S&S MK45 mufflers?
Post by: hd-dude on March 08, 2018, 07:32:40 PM
Here's a dyno for a '17 107" with a Fullsac MX and the MK45's
Title: Re: Feedback on S&S MK45 mufflers?
Post by: North Star on March 09, 2018, 02:02:06 PM
Wow! No torque dip there- amazing curves. Thanks for posting that.

I wonder if they would change much for me. My GMR 113 was tuned with Fullsac 2.0 mufflers. I since put on Crushers which is also a 2" baffle, nothing seems to have changed power/reliability wise. Ill have to think about if MK45 would work. Re-tuning is not an option since Dave Stoddart is out of the business. Plus if I was going to re-tune, Id try a 2-1 to make it worthwhile.
Title: Re: Feedback on S&S MK45 mufflers?
Post by: North Star on March 09, 2018, 02:04:55 PM
I have not measured them but i believe they are 2.25". They are a perforated baffle. The DB reducer is an 8" long, 2" louvered baffle that inserts into the end of the pipe.

If the db pipe is 2", then the baffle must be larger obviously, which would make it 2.25", or hopefully not 3".
Title: Re: Feedback on S&S MK45 mufflers?
Post by: North Star on March 19, 2018, 07:21:29 PM
I emailed S&S with the same baffle size question, and they tell me it is a 2.5" baffle. Not sure how it could perform well down low with that big a baffle, but I suppose with the db killers, which reduce the baffle down to 2" for the end 8" or so, maybe that gives back enough back pressure.