I have a couple of slip-ons for my 98 Dyna Convertible evo that do not have baffles. They are the stock PN 65747, but with a -94 instead of the -09a that's called out in the parts list. I want to add some baffles as it is too loud for me. I've attached a picture of the muffler along with some baffles I'm thinking of adding, but wanted any advice anyone is willing to offer. I'd like to achieve what is close to stock noise level and have no idea what sticking these baffles in will do, except cut down on performance. Currently running SEs with baffles and still to loud. I intend to place the baffle in the inlet side of the muffler as the opening is 1 3/4" and the inside of the muffler necks down to 1 1/2" and then opens up again to about 1 3/4" again. This will trap the baffle in place in the forward end of the muffler. I can drill and bolt it in if necessary also. If anyone knows what the stock baffles look like, I'd greatly appreciate any info on that also. Thanks in advance for any input.

 

Speaking from experience with those baffles, I had them in my set of Cycle Shack Drag pipes with an EV-38 Cam and SF Ignition at stage one. They weren't very quiet and I seriously doubt that with OEM head pipes yours will sound close to stock noise level. I had a former performance Dyno/tech tell me I needed more back pressure than open pipes afford, and to cut the baffles in half if I was after more performance. It didn't make that much more noise than a whole baffle, and I never noticed a dip in mid range but it ran really nice with my set up.(No backfiring) I put about 20K on those pipes. Never regretted it. My bike doesn't have a radio, so I didn't mind.
If you are after an OEM noise level, you had better put on the original mufflers as you had pictured. Used ones are a dime a dozen. You could try some fiberglass packing around the baffle for more quiet, but glass packing lasts only so long.

In my experience if you want to make more power with an Evo, you need to make some noise...

I look forward to hearing from people on this forum with quiet pipes...lol!

You could just buy glass wrapped baffles, or half baffles too...as I recall from Dyno testing "Khrome Werks" made the best baffles performance wise, but could not be used with glass packing...

Wyatt Gatling Steel 2 in. Pipe Baffle Set - 30-0103 Harley-Davidson Motorcycle - Dennis Kirk

Cobra Optional Reduced dB Baffle - 9026 Harley-Davidson Motorcycle - Dennis Kirk

Khrome Werks 1 3/4 in. HP-Plus Drag Pipe Baffle - 202010 Harley-Davidson Motorcycle - Dennis Kirk

 

Usually it's trial and Error... Don't know of anyone inserting baffles into a presumably punched out OEM muffler.. Hard to tell in the pics which way the louvers are going but they usually always are open to downstream...

One more thing stay away from perforated baffles, they're louder....
I think you should just try to find a decent set of slip-ons that are quiet and go from there...

 

I'm with hotrod - it truly is trial and error getting sound like you want it. Yeah, never saw stock muffler baffles totally removed.

I sincerely doubt you'd be happy with the pictured baffles you're considering. But trying to tell some else how they want their bike to sound would be ridiculous.

Do your current SE mufflers have removable baffles?

 

Thanks for the replies. I am looking for a set of stock pipes, but my bike is pristine condition and finding a really nice set is going to take some time. In the meantime for the low cost of some of the inserts, I thought I'd try. The attached picture is the neck down inside the muffler that will hold the baffle in place. After the neckdown the diameter is larger with holes that I presume have fiberglass behind them. I'm pretty sure these were stock parts, but for the life of me I can figure out how the baffles were removed if there ever were any. I found another baffle (shown below) that will allow some experimentation with moving the rear plug back and forth, It a little less than 1" diameter and the necked down diameter of the muffler is 1 1/2" so I think the set screw for the plug will fit through. As mentioned this will necessitate putting the baffle in backwards from it's intended use, plus it's smaller in diameter which would allow some wrapping. With the plug I would think it would make a more torcherous path for the sound wave to travel back and forth, but I would have thought that for the perforated baffle also. I guess it's worth a try until I can find other mufflers.

 

I would look for a set of Screaming Eagle slip ons...just my .02. There are a couple sets on eBay right now and they aint getting any cheaper. Evos are fast approaching the collectors status. I have an original set of pipes and mufflers from when my bike was new. Took them off at 14 miles. Did you ask the previous owner if he had them?

Good luck

98 Harley Davidson Dyna SuperGlide Fxd Screaming Eagle Muffler Exhaust Pipe 1998 | eBay

 

I tried those exact baffles on a set of cycle shack drags and they sounded like crap. Removed them immediately after the first startup after installation.

 

SirHarley I have SEs on it now and they are too loud. I may play around with baffles for those if I can't get anything to work on the OEMs. I'll also try the previous owner.
Paint - thanks, I guess I'll keep looking.

Anyone know what the internals on a stock set of pipes look like?

 

If your SE baffles are removable, (some were, some weren't) they are the very easiest muffler to tune for sound and flow. You can easily make them quiet as stock with minimal effort and materials.

 

Don't blame the baffles, blame the tuner!...lol! or blame the tech that gave you the advice to combine both pieces on your build. I found that the (Khrome Werks) baffles and Cycle Shack Drag Pipes with Torque cones, were an excellent combo for the EV-38 Cam and Dragtron II Air Cleaner (K&N), and Thunder slide kit with a Crane Fireball SF Ignition. I drove them for almost 10 years until my head pipes chrome peeled so badly, I had to replace them. For a while they were the most beautiful shade of Amber and Blue at the first radius of the head pipe. My spark plugs were always a perfect shade of tan and they would last for years. I posted a running video on the early days of You Tube about 5-6 years ago, but I couldn't find it. Ill keep looking when I have time. I must have posted it under another account that I couldn't log into...