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Rider
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Once again I am considering installing an Indian Cat Gutted Header. I tried this about a year ago and didn't care for the additional volume. Currently, I have Stage 1 Intake and exhaust and Stage 2 cams. What I am thinking about doing this time is gutting the Cat, but before I close it up, installing a couple of Big City Baffles in the pipes inside of the Cat Chamber. My thought is that the slightly disrupted gas path will allow both pipes to flow more equally and the baffles should reduce the DB's. My primary objective is to reduce the heat, but maintain similar DB's and performance of the stock set up. What are your thoughts?
 

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Vendor / bronze
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I think it is a good idea. I think completely gutted cat gives you a slightly uneven flow between the cylinders. A little resistance is good.
 

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Once again I am considering installing an Indian Cat Gutted Header. I tried this about a year ago and didn't care for the additional volume. Currently, I have Stage 1 Intake and exhaust and Stage 2 cams. What I am thinking about doing this time is gutting the Cat, but before I close it up, installing a couple of Big City Baffles in the pipes inside of the Cat Chamber. My thought is that the slightly disrupted gas path will allow both pipes to flow more equally and the baffles should reduce the DB's. My primary objective is to reduce the heat, but maintain similar DB's and performance of the stock set up. What are your thoughts?
Funny I was going to do similar and was told that it was not the best idea as it would still be loud ,I also gutted my cat after doing the 116 kit on my last road master and ended up with anew bike with the same mods as you have now. I then bought a new take off rear header and decayed it thinking it may have been by 116 kit and the stage 1 exhaust ,hi flow filter that made my last bike so loud. I went so far as going to Indian in Sydney to have the new header fitted and once I got there I was lucky enough that they had a bike there with the de cat ,stage 2 cams and hi flow air filter. Wow it was still was too loud and our laws are so tuff. I left my new bike as it is and just added the PVCX and custom Dyno Tune to reduce the heat as much as I could with the tune. I have tried everything you have and had the same objective . The only other thing that might be worth looking at is adding Love Jug fans where you can turn each on on or off or both on or off depending on riding conditions. I can tell you I have DB reader . meter and the decat was idling at 114 db where with the cat in place it idols at around 89db.The last thing is when I de cat my headers I di add a exhaust bend to work asa splitter to gain even air flow . But the noise level will be louder doing the de cat .
 

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I think it is a good idea. I think completely gutted cat gives you a slightly uneven flow between the cylinders. A little resistance is good.
Why would the flow be uneven between the cylinders when both head pipes merge before/at the cat? Maybe you mean flow through each muffler uneven without the diverter in there?

At any rate, just had my wife's stock Chieftain cat removed and with stock mufflers sounds wonderful, lower and slightly louder than stock but not too loud. I would definitely say less than even my Stage 1 with the cat still on. She says the heat is definitely less.
 

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The header pipes are different lengths and have different turns in them. Without the CAT to back up the exit pressure there is a slight difference in the so called back pressure on the exhaust valves.
 

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Not a great idea. Baffles work best at the end of the cans. Putting a restriction where the cat was will just serve to create more heat in that area. We have had a few customers try to install our baffles “mid pipe” against our recommendations and we have seen a couple cooked engines as a result.
 

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Rider
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Discussion Starter #7
Not a great idea. Baffles work best at the end of the cans. Putting a restriction where the cat was will just serve to create more heat in that area. We have had a few customers try to install our baffles “mid pipe” against our recommendations and we have seen a couple cooked engines as a result.
Interesting points.

I had a 2009 Harley Street Glide. That year of SG did not have a cat in the headpipe like latter years. I installed more open mufflers, and liked the deeper rumble, but the db's were too high for me. These mufflers also did not have the ability to add or switch the baffles. I installed these Big City Thunder Baffles in the head pipes where they enter the mufflers and they worked great. I didn't detect any additional heat and the db reduction was perfect.

This statement is what they post on their website for these baffles;
"The QQ Thunder Monster baffles are designed to fit stock head pipes on Harley-Davidson motorcycles as well as most aftermarket head pipes".

However, I am not an exhaust expert by any stretch of imagination, and that is why I posted the question. I just don't see these baffles being too restrictive, just shaped to change the sound wave.
 

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If you want a more of an even exhaust pressure coming out find a welder change the crossover to a fully open pipe. I think Racnray got another 6cfm after he opened his up.
 
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