CAT removed from header
Advanced
Joined: Apr 2012
Posts: 81
Likes: 0
From: MS
Have not noticed anything at all. However don’t have many miles yet. Seems that there is less heat and I can use 6th gear better. I would say probably no difference in power and only a little bit louder than with them in. I was surprised on how little the sound difference was…
Also I cut the pipe in the center of the CAT and than removed it. Had it welded back together for $25 bucks. Is it worth it??? Not sure however I think the difference in heat will make it worth it..
Also I cut the pipe in the center of the CAT and than removed it. Had it welded back together for $25 bucks. Is it worth it??? Not sure however I think the difference in heat will make it worth it..
Last edited by Bcun10t; May 5, 2012 at 08:40 AM.
Grand HDF Member
Joined: Jun 2009
Posts: 3,520
Likes: 270
From: Wellsboro, PA
I'm not a mechanic, and I don't wrench on my bike, so I didn't cut it out. Got rid of mine by putting different headpipes on. I did Vance & Hines Power Duals.
Extreme HDF Member
Joined: Dec 2010
Posts: 14,778
Likes: 69
From: Badlands of ND
I did the same on my 2012. The cat was cooking my wifes left foot. Since the change I have seen no diference in MPG, but a huge difference in heat. That has made for a very comfortable and happy wife.
Extreme HDF Member
Joined: Jun 2011
Posts: 10,216
Likes: 224
From: Glendale AZ
Mine are right on top of each other (mind you the chamber is partially divided in header) and Ive never had anything that resembles cross-talk....My opnion.... but I think that term is made up JMHO
Extreme HDF Member
Joined: Jun 2011
Posts: 10,216
Likes: 224
From: Glendale AZ
i've put on over 25,000 miles since removing my cat. no noticeable difference in mpg (that can be atttributed to that)
plus: sounds better/louder, much cooler
minus: haven't found any yet.
i just had my bike dynoed by jamie at fuelmoto. he said he experienced no problems tuning my bike. if there was any cross talk, i would think that it would be quite evident on a dyno.
plus: sounds better/louder, much cooler
minus: haven't found any yet.
i just had my bike dynoed by jamie at fuelmoto. he said he experienced no problems tuning my bike. if there was any cross talk, i would think that it would be quite evident on a dyno.
Extreme HDF Member
Joined: Jun 2011
Posts: 10,216
Likes: 224
From: Glendale AZ
Cutting it out and sealing it shut (no added pipe).
Elite HDF Member
Joined: Sep 2007
Posts: 4,928
Likes: 69
From: Near Myrtle Beach, SC
Check out where the O2 sensors are in this pic of my 2010 header:
They are positioned before the CAT, and seem to be far enough apart to be well within their respective exhaust flow chambers. I don't see why removing the CAT would contribute to a problem (crosstalk) that apparently does not exist in the stock configuration.
And besides, most folks disconnect the O2s anyway when they do a stage one or other tuning. They go away from closed loop to an Alpha N, throttle position type of world.
As for the restrictiveness of the CAT, many have talked about their impression of just how much the CAT restricts flow. Some say not much, some say a lot.
I performed some exhaust velocity measurements with my air flow meter using my stock header with the CAT, then compared that to the Fuel Moto Stainless Header. Both tests were using the Jackpot Pro-Touring mufflers. Both tests were at cold idle at an rpm of appx 1100-1200.
With the stock header, including the CAT, the right muff exhaust velocity was 19 MPH (speed of the exhaust exiting the pipe) and the left was 9 MPH.
With the Fuel Moto header, the right muff exhaust velocity was 29 MPH and the left was 23 MPH.
I wish I could have measured a catless stock header pipe, but I would expect the results to be pretty close to the Fuel Moto header exhaust velocities.
Measured sound between the stock header with the CAT and the Fuel Moto header was (at idle) 81.5 dB and 84 dB respectively.
Anyway, that's some measurements I took for my own edification to see what the difference was with the stock header versus the FM header. YMMV
They are positioned before the CAT, and seem to be far enough apart to be well within their respective exhaust flow chambers. I don't see why removing the CAT would contribute to a problem (crosstalk) that apparently does not exist in the stock configuration.
And besides, most folks disconnect the O2s anyway when they do a stage one or other tuning. They go away from closed loop to an Alpha N, throttle position type of world.
As for the restrictiveness of the CAT, many have talked about their impression of just how much the CAT restricts flow. Some say not much, some say a lot.
I performed some exhaust velocity measurements with my air flow meter using my stock header with the CAT, then compared that to the Fuel Moto Stainless Header. Both tests were using the Jackpot Pro-Touring mufflers. Both tests were at cold idle at an rpm of appx 1100-1200.
With the stock header, including the CAT, the right muff exhaust velocity was 19 MPH (speed of the exhaust exiting the pipe) and the left was 9 MPH.
With the Fuel Moto header, the right muff exhaust velocity was 29 MPH and the left was 23 MPH.
I wish I could have measured a catless stock header pipe, but I would expect the results to be pretty close to the Fuel Moto header exhaust velocities.
Measured sound between the stock header with the CAT and the Fuel Moto header was (at idle) 81.5 dB and 84 dB respectively.
Anyway, that's some measurements I took for my own edification to see what the difference was with the stock header versus the FM header. YMMV
Last edited by Lowcountry Joe; May 6, 2012 at 02:30 PM.