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I've been back and forth over removing the catalytic converters a hundred times. Taking care of the heat issue is my priority before next season, I have no intention of wasting anymore time playing with air flow, fins, lowers or anything else. (For anyone who doesn't know: since tuning my bike, the cats have been over heating and it a blast furnace riding in warmer temps).

I planned to bite the bullet and get a new exhaust system, but after talking with some buddies and a little research, I decided once and for all to de-cat my stock exhaust. I already had the wheels and mufflers off so now was the time, I just went out this afternoon and did it.

The job was fairly easy, I drilled out a center hole, then around the entire edge of the cat making holes as close as I could get. I tapped in a small chisel around the perimeter to break it loose and get any remaining pieces off the edges. The cat material is highly magnetic, which made clean up a snap, I just ran a magnetic screwdriver around the inside of the pipes a few times, which collected all the excess shavings and splinters.

Now...I'll have a wait a while to see how this will go. I have two major concerns. One is excessive noise, my Miller Mufflers are pretty much straight through and have a 2.5" exhaust port, the noise level could be over the top. The other is low end power loss and this is my main concern. I'm very anxious to get the bike together and test this out but it may be months, all depends on how soon I get my new tires on and fork service done and the weather, of course.

If I no likie, I'll just go back to my original plan of getting a new exhaust.

 

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I've been back and forth over removing the catalytic converters a hundred times. Taking care of the heat issue is my priority before next season, I have no intention of wasting anymore time playing with air flow, fins, lowers or anything else. (For anyone who doesn't know: since tuning my bike, the cats have been over heating and it a blast furnace riding in warmer temps).

I planned to bite the bullet and get a new exhaust system, but after talking with some buddies and a little research, I decided once and for all to de-cat my stock exhaust. I already had the wheels and mufflers off so now was the time, I just went out this afternoon and did it.

The job was fairly easy, I drilled out a center hole, then around the entire edge of the cat making holes as close as I could get. I tapped in a small chisel around the perimeter to break it loose and get any remaining pieces off the edges. The cat material is highly magnetic, which made clean up a snap, I just ran a magnetic screwdriver around the inside of the pipes a few times, which collected all the excess shavings and splinters.

Now...I'll have a wait a while to see how this will go. I have two major concerns. One is excessive noise, my Miller Mufflers are pretty much straight through and have a 2.5" exhaust port, the noise level could be over the top. The other is low end power loss and this is my main concern. I'm very anxious to get the bike together and test this out but it may be months, all depends on how soon I get my new tires on and fork service done and the weather, of course.

If I no likie, I'll just go back to my original plan of getting a new exhaust.

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Maybe Apples to Oranges here, I removed the cats on my Tri-Glide and added slip-ons, Lost bottom end power and way too loud..
Added a pair of Thunder Torques from DK Custom. Got back bottom end big time and toned the sound down.. Been riding with them for a few years now.. Some of the old street rod guys call them Lolly-Pops...
 

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doubt it will be much louder. Your ATS should make up for low end.
Think you'll be just fine.
Spray some WD40 on muffler opening before you put on pipe. It will slide right on and hurt nothing.
 

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I think you'll be fine. Hopefully it does something for your heat issues.
 

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It will be a long winter waiting for these results Pain. I too am considering removing the cats. I have had a very similar experience to Pain's XCT heat issues. I have tried to do everything in an effort to reduce heat felt. Just learning about the Thunder Torque inserts.... seem like a nice solution to regain some loss bottom end and reduce any added sound as a result of removing the cats.

For those who have removed the cats, did you notice a large increase in sound? I could handle a slight increase, but really don't want much more volume. Most posts I have read have never really mentioned a big increase in loudness.
 

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I was talking about it to PaiN today before he did it; mentioned that I didn't notice a significant increase, but I also had OEM mufflers, too...
 

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Discussion Starter #8 (Edited)
Spray some WD40 on muffler opening before you put on pipe. It will slide right on and hurt nothing.
Helps getting pipes off too... ;)

Hopefully it does something for your heat issues.
Those cats caused me a lot of headache.....I gave them the finger after I dumped them in the trash.
 

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For one thing... you just blew that dyno tune you paid for. Does it really get that hot in Connecticut? I mean, it's not like you ride in 120 degree temps in Arizona.

Secondly... now that my best friend has a dyno and we have done a LOT of testing... we both say all the time, "Just when we think we know something about exhaust tuning, we learn that we really know nothing about exhaust tuning". It's SO TRUE.

However, on most machinery we have played with, the factory head pipes and some relatively small diameter slip-ons out-perform a full replacement exhaust system... As long as the engine is not radically modified. The Victory baggers, the HD baggers, same story. The cats don't seem to hurt, but actually help, in cases where just breathing mods or breathing mods and cams are done.

It was long thought by my friend that THOSE CATS MUST GO! but he has changed his tune (pun intended) on that.
 

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I pulled the cats out of my XR exhaust and ran it for two or three years without em. I did it at the same time I made the thrush mufflers for it. I didn't notice power loss and the heat was somewhat less. Also, I just screwed a slide hammer right into the center of the cats and hammered them out. Very easy and simple.
Unless you are going drag racing, I doubt it will make any difference in performance.
 

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Unless you are going drag racing, I doubt it will make any difference in performance.
Where performance will be lost is at the BOTTOM/LEFT SIDE low rpm power output. This would not be "drag racing" performance lost, but every day drivability performance lost.

Here.... Blue with cats removed. Red with new stock head pipes and cats in them. The bike especially performs better at the low rpm, but it also makes more horsepower at the top of the tach as well.

This is a cammed bike. One would think that without the cats it would run better at high rpm... guess what... one would be wrong to think that.
 

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You just threw away some platinum
Seriously? That means I did too. How much platinum is in there, and how does one recover it?
 

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I think it's a small amount, along with a couple other rare metals. That's why people go around and steal catalytic converters. There worth decent money, because of the metals that are in it. You wouldn't get that much for the little ones that are in our bikes
 

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Coin Toss

The dealer I got my bike from put their mufflers on it, basically gutted stock mufflers. Bike was to loud to me after riding it that way for some time. I then put glass pack car mufflers inside of the stock muffler housings. Bike was much quieter, still the glass packs you can look straight through. Now right or wrong I went ahead and removed the cats. Big difference? Did not do a dyno run, so to me as mentioned a coin toss. Heat wise I live in Arizona, any little less heat helps, ha, ha. Glad I did it, I guess, it's a done deal. Oh yes everybody always talks about back pressure so I guess the bike has that now, removed the left side muffler and capped it off, it did make it a little quieter to me. Again no dyno runs yet, one day. Have had it running with one muffler for maybe over a year now. As I mentioned it ought to have some back pressure, one day I will emove the old cross over pipe for the left muffler for now it is some back pressure. I know there is a little scoop inside that redirects some flow to the left side, that is why one day I will cut it out and patch the pipe. Then maybe I can get it to a dyno!
 

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Too many people get caught up in dyno numbers. Do you realize that your blue line is better than most peoples tuned non cammed 106 numbers and they "feel" like the bike runs great and has excellent torque. My numbers are not as good as your blue line numbers and my bike "feels" great to me and they are quite a bit higher than stock. Using the logic I hear about these dyno numbers, a guy with a stock bike can't even get from here to there. I remember when I rode a stock bike and it felt great.

The purpose of removing cats is to reduce heat. Since that is there purpose, to get real hot and burn off gases, removing them solves 1 thing, less heat while riding the motorcycle. Yes there may be a "loss of performance" but that is all relative. If I were to remove my cats, I will still have more performance than a stock bike. Again, how much performance a guy needs is up to him. Again, I don't tell a guy with a stock bike his bike does not perform because it DOES.

I ride to get from here to there and enjoy the outdoors. I only did my mods to richen up a lean engine that ran hot. Everything I do to this bike is to get it to run cooler. As a benefit, yes I gained hp and torque. Did I need it, not really. Do I benefit from it? Sure I do.

But would I enjoy a cooler bike and a little less "performance" Hell ya I would.

Sorry, rant over.
 

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Good and interestingly read here, "subscribed"
 

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Too many people get caught up in dyno numbers. Do you realize that your blue line is better than most peoples tuned non cammed 106 numbers and they "feel" like the bike runs great and has excellent torque. My numbers are not as good as your blue line numbers and my bike "feels" great to me and they are quite a bit higher than stock. Using the logic I hear about these dyno numbers, a guy with a stock bike can't even get from here to there. I remember when I rode a stock bike and it felt great.

The purpose of removing cats is to reduce heat. Since that is there purpose, to get real hot and burn off gases, removing them solves 1 thing, less heat while riding the motorcycle. Yes there may be a "loss of performance" but that is all relative. If I were to remove my cats, I will still have more performance than a stock bike. Again, how much performance a guy needs is up to him. Again, I don't tell a guy with a stock bike his bike does not perform because it DOES.

I ride to get from here to there and enjoy the outdoors. I only did my mods to richen up a lean engine that ran hot. Everything I do to this bike is to get it to run cooler. As a benefit, yes I gained hp and torque. Did I need it, not really. Do I benefit from it? Sure I do.

But would I enjoy a cooler bike and a little less "performance" Hell ya I would.

Sorry, rant over.
Ummm.... the dyno is just a measuring tool. All it does is allow you a repeatable way to measure power and air/fuel ratio... THAT'S ALL.

Take a bone-stock Cross bike, put a Power Commander on it and tune it on a dyno. It will gain performance and run cooler.

Now remove the cats and re-tune it.

You will see a LOSS in low end torque from what it had stock and the difference in heat on the rider will be quite minimal.

The chart I posted QUITE CLEARLY demonstrates the benefit of the cats as far as exhaust velocity and performance are concerned. The guy whose dyno graph that is spent a lot of time, effort, and money only to discover that removing the cats was a bad idea. Your bikes, your call, take the cats out and give them the finger as you toss your low end torque in the trash... fine with me. I was just trying to help.

Done now.
 

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No worries half crazy. I respect your input. Just throwing my 2 cents in.

Happy new year man.


Sent from Motorcycle.com Free App
 

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So I would be wondering what its going to do to the O2 sensor readings. Its going to be reading "rich" all the time basically and keep trying to cut back on fuel. Lean conditions will make a motor run hot also, so you could be rite back where you started. Whats the work around for this?
 
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