How much cat to remove?
Intermediate
Joined: Jul 2024
Posts: 25
Likes: 26
From: Sioux Falls, South Dakota
I don't agree with that statement. I removed the baffles from mine, and still have cats as well like he said. Sounds amazing and have had nothing but compliments on it. In fact I like it so much I'm not even gonna bother with anything aftermarket
Seasoned HDF Member
Joined: Jan 2011
Posts: 157,458
Likes: 57,015
From: Michigan 15 Minutes East Of Hell
HDF Community Team
Joined: Nov 2012
Posts: 6,189
Likes: 2,419
From: USA
Hmmm, American Custom is seemingly claiming to be CARB compliant. Nowhere do I see them claiming to trim the catalytic matrix. Which makes me wonder if they actually are.
If it's just a hole punched through the matrix, that's illegal and they will eventually be prosecuted for it.
If the matrix is shaved down, unless they've the testing to show it's still effective, that too is illegal and they'll eventually be prosecuted for this. I doubt they've done the compliance testing. They certainly don't mention it on their web page. The catalytic converter matrix, being brittle, is demanding when it comes to grinding it down without breaking it up. Sure, it can be done, a grit faced disc will do the job, just like a glass or ceramic shaper uses. But would they do this? For such a cheap price? And would they not brag about it on their web page?
Makes me suspect they actually aren't doing anything with the catalytic converter after all. But, if someone has a picture of this catalytic converter modification, well, we'll see what we see then.
If it's just a hole punched through the matrix, that's illegal and they will eventually be prosecuted for it.
If the matrix is shaved down, unless they've the testing to show it's still effective, that too is illegal and they'll eventually be prosecuted for this. I doubt they've done the compliance testing. They certainly don't mention it on their web page. The catalytic converter matrix, being brittle, is demanding when it comes to grinding it down without breaking it up. Sure, it can be done, a grit faced disc will do the job, just like a glass or ceramic shaper uses. But would they do this? For such a cheap price? And would they not brag about it on their web page?
Makes me suspect they actually aren't doing anything with the catalytic converter after all. But, if someone has a picture of this catalytic converter modification, well, we'll see what we see then.
Road Master
Joined: Mar 2024
Posts: 1,157
Likes: 504
From: Colorado
I never intended to leave it like that. And it was definitely a performance hit. Not huge, but obvious. Exhaust can't add horsepower, it can only rob it with reversion. I added an open baffle back in to dampen the open potatoe gun sound and lollipops to correct the obvious reversion. The sound is better, and it is a performance increase better than stock. I actually put very little stock in such things, but it is... Dare I say, significant, and obvious. I already had less restriction and an open pipe, so it must be reversion.
Now that if had it for a while, I have tired of it. Yes, it definitely sounds better than stock, but it kind of drones on. It's all deep with no rasp. I never wanted loud just to be loud. I hate obnoxious pipes. I want a good sounding throaty exhaust. It was a temporary experiment. I always planned on full exhaust. It was worth it.... for temporary. If I wasn't going full exhaust, I would replace them with proper slip-ons that have at least been tuned to sound right and don't induce reversion.
If you like the sound... Fine. Don't add anything else... But get some lollipops, and you will see for yourself.
Seasoned HDF Member
Joined: Jan 2011
Posts: 157,458
Likes: 57,015
From: Michigan 15 Minutes East Of Hell
Hmmm, American Custom is seemingly claiming to be CARB compliant. Nowhere do I see them claiming to trim the catalytic matrix. Which makes me wonder if they actually are.
If it's just a hole punched through the matrix, that's illegal and they will eventually be prosecuted for it.
If the matrix is shaved down, unless they've the testing to show it's still effective, that too is illegal and they'll eventually be prosecuted for this. I doubt they've done the compliance testing. They certainly don't mention it on their web page. The catalytic converter matrix, being brittle, is demanding when it comes to grinding it down without breaking it up. Sure, it can be done, a grit faced disc will do the job, just like a glass or ceramic shaper uses. But would they do this? For such a cheap price? And would they not brag about it on their web page?
Makes me suspect they actually aren't doing anything with the catalytic converter after all. But, if someone has a picture of this catalytic converter modification, well, we'll see what we see then.
If it's just a hole punched through the matrix, that's illegal and they will eventually be prosecuted for it.
If the matrix is shaved down, unless they've the testing to show it's still effective, that too is illegal and they'll eventually be prosecuted for this. I doubt they've done the compliance testing. They certainly don't mention it on their web page. The catalytic converter matrix, being brittle, is demanding when it comes to grinding it down without breaking it up. Sure, it can be done, a grit faced disc will do the job, just like a glass or ceramic shaper uses. But would they do this? For such a cheap price? And would they not brag about it on their web page?
Makes me suspect they actually aren't doing anything with the catalytic converter after all. But, if someone has a picture of this catalytic converter modification, well, we'll see what we see then.
Cruiser
Joined: Apr 2021
Posts: 176
Likes: 43
From: New Port RicheyFL
Stock Harleys sound horrid. Much too quiet, no bark, no depth. Read anyone that has just cut the baffles out, it sounds terrible, and it's a performance hit. When I cut mine out, and left cats in, that is exactly what it was. Sound is subjective... Yes, it is louder, yes deeper, but no bark, droning. There is nothing about a big open pipe echo chamber that sounds good... At least to me, and many others.
I never intended to leave it like that. And it was definitely a performance hit. Not huge, but obvious. Exhaust can't add horsepower, it can only rob it with reversion. I added an open baffle back in to dampen the open potatoe gun sound and lollipops to correct the obvious reversion. The sound is better, and it is a performance increase better than stock. I actually put very little stock in such things, but it is... Dare I say, significant, and obvious. I already had less restriction and an open pipe, so it must be reversion.
Now that if had it for a while, I have tired of it. Yes, it definitely sounds better than stock, but it kind of drones on. It's all deep with no rasp. I never wanted loud just to be loud. I hate obnoxious pipes. I want a good sounding throaty exhaust. It was a temporary experiment. I always planned on full exhaust. It was worth it.... for temporary. If I wasn't going full exhaust, I would replace them with proper slip-ons that have at least been tuned to sound right and don't induce reversion.
If you like the sound... Fine. Don't add anything else... But get some lollipops, and you will see for yourself.
I never intended to leave it like that. And it was definitely a performance hit. Not huge, but obvious. Exhaust can't add horsepower, it can only rob it with reversion. I added an open baffle back in to dampen the open potatoe gun sound and lollipops to correct the obvious reversion. The sound is better, and it is a performance increase better than stock. I actually put very little stock in such things, but it is... Dare I say, significant, and obvious. I already had less restriction and an open pipe, so it must be reversion.
Now that if had it for a while, I have tired of it. Yes, it definitely sounds better than stock, but it kind of drones on. It's all deep with no rasp. I never wanted loud just to be loud. I hate obnoxious pipes. I want a good sounding throaty exhaust. It was a temporary experiment. I always planned on full exhaust. It was worth it.... for temporary. If I wasn't going full exhaust, I would replace them with proper slip-ons that have at least been tuned to sound right and don't induce reversion.
If you like the sound... Fine. Don't add anything else... But get some lollipops, and you will see for yourself.
Road Master
Joined: Mar 2024
Posts: 1,157
Likes: 504
From: Colorado
You are talking about getting closer to ideal. Ideal cycle, all exhaust gases are expelled, and 100% fresh charge taken in. Exhaust system can only impair that, or not impair that... It can NOT improve that... Better than ideal. If an exhaust "improves" anything, it is only fixing what was robbed. My lollipops didn't add any horsepower, they corrected horsepower stealing reversion. That is a long time proven exhaust tech.
What is also proven is big open pipes on naturally aspirated engines are detrimental to performance. Large diameter pipes decrease velocity... That hinders scavenging.
What is also proven is big open pipes on naturally aspirated engines are detrimental to performance. Large diameter pipes decrease velocity... That hinders scavenging.
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Intermediate
Joined: Jul 2024
Posts: 25
Likes: 26
From: Sioux Falls, South Dakota
Still absolutely love the sound of my softail without the baffles. And have not noticed in the slightest any gain or loss in power, if any either way it's negligible and not noticeable, for me anyways
Road Master
Joined: Mar 2024
Posts: 1,157
Likes: 504
From: Colorado
You need to twist more then. It's a noticeable hit. 😉 Spend the $50 to put lollipops in and you will see exactly what it is costing you. Those made it sound a bit better (deeper) as well. Cheapest power you will get.
