Is there any difference between 2003 stock slipons and late model slipons as far as restrictions? Some where on here it was suggested that I try newer stock pipes if I wanted to quiet my RKC down without hindering breathability but when I contacted three different dealers about new take offs, they could not answer if they flowed better or not.

randy

 

I have 2012 slipons on my 07. They flow a lot better then the stock ones. Part of the reason is they do not have cats in them. I can't help you versus the stock 03 mufflers. For me they are perfect. Louder but not obnoxious and the headers are definitely cooler. Best part they were free. I just had to dumpster dive for them.

 

You have the mufflers with the round tips? Yes, those are full of an alloy catalytic converter that tends to discolor the chrome due to heat. I just cut apart some of the later ones, they are chambered and full of an asbestos like insulation.

Cats actually flow surprisingly well. I would have thought better than the newer others but that they would be more quiet.

Don't know of any figures to back that up but there should be little to no money in the gamble of trying them. Worse case scenario is, you end up with better looking mufflers and newer chrome. Loads available.

 

Look for late model CVO take-offs for the best flow of stock mufflers. Nice sound and good torque. I paid $200 for mine from eBay.

 

Very loosely and generically, I would expect the later mufflers to have better flow than the earlier ones due to engine size increase.

That arguement could easily be countered by the increased sound reduction required by EPA. Sound doesn't equate flow when done right, but many times it's not, so flow is killed in the name of noise reduction by poor engineering.

Equally, to counter the counter arguement, catalytic converters absorb some sound, reducing the acoustic load the muffler must carry.

In the end, I've tried a few different stock mufflers, and what I think/recall are an older set of E-glide mufflers are the quietest mufflers I've found for my 04 RK. I've not suffered any appreciable power loss from them.

 

I'm running a stock 88 bore but 510 cams with a power commander. I like the sound of stock pipes but I recently took off my kirkers and reinstalled the original pipes that came on the bike. It really pulled it down. If I could find the stock sound that doesn't hinder the cams id be happy but I think there is no such animal.

randy

 

Supertrapp!!

http://www.supertrapp.com/images/pdfs/hot-sauce-db.pdf

 

Of course, the OEM Street Glide 2-into-1 will only produce half as much noise because there's only one muffler ...

 

Randy,

If you are looking for pipes for a 2003 with an 88" I really like my HD Performance Touring 65259-00 mufflers. For 00-06 they were what was used on the CVO bikes. Not sure if you can find them new anymore.

I also had a later pair CVO pipes. Those also flowed well and were quiet. Watch out of '06 CVO pipes, they have the cat in the mufflers.

 

I had a set of CVO slip ons mounted on my 07 Bagger and still found them too loud so I installed a set of 2010 stock mufflers, mind you I have true dual head pipes.