I know a lot of you folks with bikes with the stupid EPA mandated cat converters out there wonder if taking out the cat will increase performance and sound. While the answer to this question is somewhat subjective, I want to share a video illustrating the reaction of a guy who did just that. As you will see the removal of the cat made barely any difference in loudness. Abe the rev tone was deeper but he does not seem too happy with the results considering the amount of time invested.

It is my opinion that removing the cats alone is not going to help much. You must , if you decide to do so, follow up with new pipes and probably new head pipes , to really notice performance and sound differences worthy of the time invested. Many also say that you can keep the cat , change the pipes, and depending on replies accompesvgetting very good sound for a fraction of te time and labor spent removing just the cat....which looks like a pain in the *** anyway

God luck fellas. http://m.youtube.com/?appcache_off=1...?v=YT6o1FouizM

 

Just about everyone I know that's removed the cat (myself included but I did via a header replacement) did so for the purpose of decreasing the heat put out by the cat.

Performance and sound seems to be down way down the list of objectives.

And that's for the youtube link...don't know what the tsunami vids has to do with this topic but thanks anyway

 

removal of the cat (as mentioned above) is done to reduce the heat on the bike... not for sound or performance , new slip ons will give a deeper louder sound if thats what a person is looking for ...and as far as time invested ? whats a couple hours of easy work compared to a lifetime of not dealing with a bike so hot your passenger complains everytime they are on it .... Cat removal / one of the best things you can do to the new bikes ....

 

This is true, when i cut the cat out, heat droped quite a bit, got better sound with a night stick, and it only took a couple hours.

 

I removed the CAT, and did a Db comparison with and without. There was a 1 or 2 Db increases @ idle. I couldn't do a test @ 2500 RPM because I had no one here to turn the throttle while I held the phone.

This is what i know while riding.

The bike is louder, by how much I don't know.
Is there less exhaust restriction? yes.
Do I have better throttle response I believe so.
Is there less heat? yes.
Would I cut it out again? yes I would.

When I cut the cat open there was fine sentiment (crap) trapped between the metal plates. Will this build up over time ? I don't know.
So far I don't see any issue with the CAT being out

With_CAT-Warm
http://youtu.be/wdAIilLAjHA

Without_CAT-Cold
http://youtu.be/KNAj545lrE4

Without_CAT-Warm
http://youtu.be/qEzGVRRufD8


SDLS

 

Performance wise, removing the Cat will not give you the performance boost an after market 2-1-2 will give you either. Will it run cooler, I would suspect so but I wouldn't expect much other change

 

It's worth the effort just to remove the concentration of heat in the area of the CAT. Ask anyone that has been on any parade rides, or in slow traffic on a summer day.

As for the performance after CAT removal, well you are dealing now with a modified Harley stock header that is not very good in the first place. There won't be much if any substantive performance gain from a simple cat removal. Reduced heat, a little different sound, and a few new places for the stock to start rusting (the welds).

After taking the stock header off, I would never put it back on. Aftermarket 2-1-2 or 2-1 is the ticket. Then you have a good base on which to build your various stages of performance upgrades. You pay a lot for the bike. Don't skip on the small stuff.

 

removing the cat and adding xied's made my bike more enjoyable to ride...not looking for a performance increase.

 

The heat is the many issue, Sound is better , deeper and louder with a new slip-on. mine was for sure. Why would you remove the cat and then follow up with a new head pipe? That would be a waste of time.

I bought a take off head pipe from a fourm member, de-cated it had my Indy tig weld it back together with SS wire so it wont rust. Took a total of 2 hrs (including beer breaks) and spent a total of $75. Very happy with the out come, and would do it again.

 

Removing some heat from my foot and leg was my motivation to cut the cat out. It was my first mod too. Would do it again. I also liked the deeper sound it gave me also.