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NS200 AS200 Catalytic converter removal (Decat, Cat delete)

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  • #1

    NS200 AS200 Catalytic converter removal (Decat, Cat delete)

    Hi everyone,

    Hope things are going good in the lockdown. I had weekends to spend quality time in my motorcycle making some minor modifications.
    I feel that always catcons are pretty restrictive in nature although newer BS4 bikes use bigger and bulky ones built inside the muffler assembly. Which caused their price to be much higher than BS3 versions.

    Notable weight from BS3 to BS4 about 3 kgs heavier in muffler.
    So have disassembled the bend pipe and have sliced the catcon with angle grinder.

    Click image for larger version Name: IMG_20200524_160945.jpg Views: 1 Size: 20.6 KB ID: 2004289

    Catalytic converter weights around 0.5kgs

    Click image for larger version Name: IMG_20200524_160939.jpg Views: 1 Size: 20.0 KB ID: 2004290

    Corrugated roll type Catcon

    Have used 1.7 inch diameter pipe 18 gauge 304SS to replace the Catcon measured and cut replicating similar length.

    Click image for larger version Name: IMG-20200524-WA0049.jpg Views: 1 Size: 20.0 KB ID: 2004291

    Welded one side onto the bend pipe installed back on the bike marked and aligned Tac welded in place before running full weld.

    Click image for larger version Name: IMG_20200524_175944.jpg Views: 1 Size: 20.9 KB ID: 2004292

    Ignore poor finishing on welding since it's been quite a while on welding.

    Finished the bend pipe with wire brush wheel and some minor sanding with flap wheel.

    To add did powder coat with some high temperature powder coating which hardly costed me 150 bucks.

    Click image for larger version Name: IMG_20200601_195333.jpg Views: 1 Size: 18.6 KB ID: 2004293

    Click image for larger version Name: IMG_20200601_195340.jpg Views: 1 Size: 16.7 KB ID: 2004294

    Click image for larger version Name: IMG_20200601_195345.jpg Views: 1 Size: 16.8 KB ID: 2004295

    Click image for larger version Name: IMG_20200601_195357.jpg Views: 1 Size: 16.3 KB ID: 2004296

    Also to note post this have checked pollution with a local certifier. It passed with flying colors.

    So no problem with law breaking or so.

    I guess this write-up will be helpful, do discuss and comment on the workmanship.

    Thanks and regards.
    Manoj Sivaraman..
    Last edited by xBhp; 06-03-2020, 05:26 PM.
    Tags: None
  • #2
    Re: NS200 AS200 Catalytic converter removal (Decat, Cat delete)

    Thread approved.

    Comment

    • #3
      Re: NS200 AS200 Catalytic converter removal (Decat, Cat delete)

      Weird to know that this passed the air pollution test. More interestingly, does it pass the sound pollution test?

      Comment

      • #4
        Re: NS200 AS200 Catalytic converter removal (Decat, Cat delete)

        Originally posted by Zapps View Post
        Weird to know that this passed the air pollution test. More interestingly, does it pass the sound pollution test?
        Audibly the note gets slightly throaty. No much change still bike is very quiet like normal NS200.
        Difference will be like the note on RTR160 and RTR 180. (Just for a comparo)

        Comment

        • #5
          Re: NS200 AS200 Catalytic converter removal (Decat, Cat delete)

          Originally posted by Manoj Sivaraman View Post
          So have disassembled the bend pipe and have sliced the catcon with angle grinder.

          Why did you do this? For the weight reduction?

          Ignore poor finishing on welding since it's been quite a while on welding.

          Finished the bend pipe with wire brush wheel and some minor sanding with flap wheel.

          You did this yourself? The welding and sanding?

          To add did powder coat with some high temperature powder coating which hardly costed me 150 bucks.

          The muffler looks really good. The exhaust pipe in my AS200 has started to develop a little rust. I would want to do this too.
          Please share the materials you used and describe the procedure a little bit. Can you post a picture of the powder coat? Was it a spray can? Did you apply a coat of paint over the powder coat?

          Also to note post this have checked pollution with a local certifier. It passed with flying colors.

          Why would Bajaj include this if it was not required to pass pollution test?
          Questions in bold.
          What is the part that remains on one side of the pipe? Is it the muffler? How was it connected to the catcon which you removed? I mean just a metal strip or was there a tube through which air would go from that part to the catcon?
          Last edited by guptavis; 10-24-2020, 06:18 PM.

          Comment

          • #6
            Re: NS200 AS200 Catalytic converter removal (Decat, Cat delete)

            Originally posted by guptavis View Post
            Questions in bold.
            What is the part that remains on one side of the pipe? Is it the muffler? How was it connected to the catcon which you removed? I mean just a metal strip or was there a tube through which air would go from that part to the catcon?
            Why did you do this? For the weight reduction?
            Not exactly, but it's one of the reasons.
            Catcon is a major restriction, causes turbulent flow in exhaust.
            We need flow to be less turbulent.

            You did this yourself? The welding and sanding?
            Yes, did all the welding and sanding myself. I have the all the required tools at home.

            Please share the materials you used and describe the procedure a little bit. Can you post a picture of the powder coat? Was it a spray can? Did you apply a coat of paint over the powder coat?
            Powder coating cannot be done at home. It is a powder based coating done by cathodic deposition. Curing is based on thermosetting procedure. You have high temperature as well as low temperature powder coatings. Ensure you do the high temperature one.
            Else you can cand it down and go for Hitemp aerosol can paints. They do last upto a year or so. ie.rustoleum, etc.

            Why would Bajaj include this if it was not required to pass pollution test?

            Bajaj cannot push out a vehicle without catcon unless it carries closed loop fuel injection system, only applicable for BS3 bikes.
            The pollution test we do on local test centres are not the exact standards. For example these ppl are not updated to newer standards. There is difference between the test procedure at ARAI, were every bike post design and development goes through rigorous testing. This mod is completely safe on engine as you are reducing the backpressure by a good margin.

            The boxy part under the engine at the bend pipe is the exhaust resonator. It aids in creating a negative pressure (vaccum) at lower speeds causing scavenging effect. This is what bajaj proudly calls as exhausTEC.

            I guess answer are informative.

            Thanks and regards
            Manoj Sivaraman..

            Comment

            • #7
              Re: NS200 AS200 Catalytic converter removal (Decat, Cat delete)

              Originally posted by Manoj Sivaraman View Post
              I guess answer are informative.
              They are very informative. Thank you for explaining Manoj.

              Yes, did all the welding and sanding myself. I have the all the required tools at home.
              Great! Are you an engineer by qualification? You really did stay true to your studies then. I've never seen a welding machine since welding workshop in 1st year.

              Else you can sand it down and go for Hitemp aerosol can paints. They do last upto a year or so. ie.rustoleum, etc.
              Thanks. I have been thinking of using the Hi-Temp spray can. Just got dissuaded by some posts that said if you leave some rust/moisture before the paint, it can actually get trapped under the paint and make it worse!

              Comment

              • #8
                Re: NS200 AS200 Catalytic converter removal (Decat, Cat delete)

                Originally posted by guptavis View Post
                They are very informative. Thank you for explaining Manoj.

                Yes, did all the welding and sanding myself. I have the all the required tools at home.
                Great! Are you an engineer by qualification? You really did stay true to your studies then. I've never seen a welding machine since welding workshop in 1st year.

                Else you can sand it down and go for Hitemp aerosol can paints. They do last upto a year or so. ie.rustoleum, etc.
                Thanks. I have been thinking of using the Hi-Temp spray can. Just got dissuaded by some posts that said if you leave some rust/moisture before the paint, it can actually get trapped under the paint and make it worse!
                Hi, Gupta

                Yes, I'm a mechanical engineer. Now pursuing my masters after 2 yrs of automotive experience. But trust me no college will teach these. Sometime we need to get our hands dirty. I love to work practically rather than go theory all the way.

                If possible get it sand blasted before painting with high temp paints.

                Thanks and regards
                Manoj Sivaraman..

                Comment

                • #9
                  Re: NS200 AS200 Catalytic converter removal (Decat, Cat delete)

                  A small update to this thread..

                  Post the cat delete the bike performance is definitely improved and bike tops around 151Kmph.
                  BS4 NS200 exhaust is way throaty and grunty. I'm a fan of it since I drove one. Wanted my AS200 to sound similar. So quest started on how the internals differ from each other. Found out a bunch of informations.

                  The catcon on the bend pipe is now moved to the underbelly unit.
                  (So if anyone is willing to do a catdelete, now it's easy to just plonk in the BS4 bend pipe. It's a direct fit costing 1800ish. Advantage: you don't need to do the surgery I did. And you get a free flow bend pipe with OE finish).

                  The BS4 muffler now houses a bigger catcon like it's KTM cousins. This is mainly done to increase the temperature at catcon by effectively insulating the entire catcon inside the muffler. Rather having them exposed under to incoming air flow which reduces the catcon temperature.

                  The new BS4 weighs around 1.5kgs more than BS3.
                  BS3 at 3.5kgs and BS4 at 4.8kgs.
                  I need the lowest weight and the best sound. So bought a used BS3 exhaust and went with a small surgery..

                  From here let the pictures speakClick image for larger version Name: IMG_20201025_152140_20201026113537154.jpg Views: 1 Size: 20.6 KB ID: 1972396Click image for larger version Name: IMG_20201025_165609.jpg Views: 1 Size: 19.5 KB ID: 1972397Click image for larger version Name: IMG_20201025_152145.jpg Views: 1 Size: 19.0 KB ID: 1972398

                  Thanks and regards
                  Manoj Sivaraman..

                  Comment

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