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[Texas 103]

I did not core mine out. I used a 3/8" 12" long carbide drill on an drill extension. It was a alot more work but I was able to remove alot more of the cat. During these cold winter night that are coming I may try to remove additional remains. I only have a little bit remaining on the bottom. I have added 1 3/4" Fullsac baffles and for the price the performance has improved greatly. I can still hear the radio. Best dollars I have ever spent on an exhaust upgrade.

 
     Brad

Brad,

Did you simply drill around the outside of the cat and finish it off with a chisel?? Looking for ideas to get the rest of mine out>>> too bad there isn't a good  1 3/4 hole saw that would take the rest of it ...Even thought about pulling the pipe, possibly cutting it  on  the back side ,pulling the rest out and MIG weld it it back..Based on the  dyno info I've seen  I'm just wondering if we are not giving a little up. in the higher RPM range because of it being a 1 1/2" opening vs the rest of the pipe being 1 3/4" Thanks Greg

[SBB]

Brad,

Did you simply drill around the outside of the cat and finish it off with a chisel?? Looking for ideas to get the rest of mine out>>> too bad there isn't a good  1 3/4 hole saw that would take the rest of it ...Even thought about pulling the pipe, possibly cutting it  on  the back side ,pulling the rest out and MIG weld it it back..Based on the  dyno info I've seen  I'm just wondering if we are not giving a little up. in the higher RPM range because of it being a 1 1/2" opening vs the rest of the pipe being 1 3/4" Thanks Greg

Greg

Did you see my red lines for the exhaust flow in post # 143?
The front pipe is being restricted.
If any is to be taken out, I think "ALL" of the cat needs to come out.
But what do I know?

 

[SBB]

On Thursday I tried to install the D&D Fatcat on the 09 SEUC.

Didn't fit well.

I came to this thread to review it and check out my options.

Decided that IMHO drilling out only part of the cat was not a good solution for me. (FOR ME)

I was bummed about the D&D so Nancy and I went out to eat and pick up some Cam II 110.

Dinner was good and the fumes from the 110 fuel cleared my head.

Came back home and reapproached the D&D and it fits now.

Doesn't change my concerns on drilling out only part of the cat in the original pipe.

But doesn't matter anymore, the Fatcat fits.

And that's what counts.

Good luck on the cats!

          

[naitram]

what did you do differently that made it fit?

[hdbrad03]

Brad,

Did you simply drill around the outside of the cat and finish it off with a chisel?? Looking for ideas to get the rest of mine out>>> too bad there isn't a good  1 3/4 hole saw that would take the rest of it ...Even thought about pulling the pipe, possibly cutting it  on  the back side ,pulling the rest out and MIG weld it it back..Based on the  dyno info I've seen  I'm just wondering if we are not giving a little up. in the higher RPM range because of it being a 1 1/2" opening vs the rest of the pipe being 1 3/4" Thanks Greg

Yes I drilled around the CAT then I bought a 3/4" x 1/8" X 36" peice of steel stock and ground a chisel point on it. I cleaned about 95% of the CAT. I may work on removing more during the cold days of winter.

 
     Brad





'\

[SBB]

what did you do differently that made it fit?

Had to rework the mounting bracket under the transmission to shim out the header about a 1/2".
That translated to the inch I needed for clearance at the rear axil.
The 09's are wider at the rear than the previous years.
Like a dumba$$ I just assumed everything would fit perfectly.
It didn't, but with a little help it does now.

 

[Screamin]

.

[Fullsac Performance]

Yes I drilled around the CAT then I bought a 3/4" x 1/8" X 36" peice of steel stock and ground a chisel point on it. I cleaned about 95% of the CAT. I may work on removing more during the cold days of winter.

 
     Brad

The Lumberjack method. Right on! Thats how I would have done it.
I bet an air chissel would make the cat turn into a lot of small pieces pretty quick too.


Steve



'\

[GregKhougaz]

Hey Silver Black,  I don't think we have that much of a disagreement. 

Your right about yours but I went back and look at earlier post and Jim said his was about 7" long and per my measurements mine is also

Can't account for the difference in measurements.  But I did measure. 

Look again at his post 8 the rear header pipe has an unimpeded flow path, then look at the bottom (front header) and you can only see a small portion of it.

You're right that the rear header does not have a straight path but from what I saw, it is not impeded.  It is certainly not perfect.  The photo flattens out the view and may make it look "impeded."  Note that even in your revised drawing, the front header flow takes two small 90* turns and is thus "impeded." 

No offense Greg but getting the job done is not what I'm looking for, I want it to flow all it can. 

None taken(and none intended here either!  Discussion is good for all of us, I think.  I understand your goal.  Not sure it could make a difference.  I don't claim to be an expert so I'm happy to stand corrected.  That's one way I learn things.  We'd have to have a way of measuring the flow to see if there is a difference.  I did not have a way of getting every scrap of the cat out and did not want to risk damage to the pipe by scraping or the heat created by drilling.  The point is that you get a lot more flow this way.  We started my engine with the muffler off with and later without cat and the difference was pronounced.  The next best alternative may be to purchase a used set of 96" header pipes where someone has "upgraded" to aftermarket headers.  If I could do that and then re dyno, I'd know if there is any difference.... 

[SBB]

Thanks Greg!
Our goals are the same.
Getting the best we can out of our bikes for the least money involved.


I agree with you below,

The next best alternative may be to purchase a used set of 96" header pipes where someone has "upgraded" to aftermarket headers.  If I could do that and then re dyno, I'd know if there is any difference.... 

I have a fairly good "in" at my Harley shop and have asked for a 96" header, when they start changing pipes on other bikes.

Good luck on yours!

SBB

[dartman]

Greg, when I removed mine, I had my friends Street glide beside me for comparison, with the core removed both header pipes dunp into a common collector before traveling through the drilled cat, with the cat in place there was a noticeable difference in exhaust volume and exit speed between the two, after the 110 was louder and appeared to have a stronger exhaust then the 96, im guessing that changing the entire system would yield very little in the way of seat of the pants performance.

[9 1/2 Beers]

"I have a fairly good "in" at my Harley shop and have asked for a 96" header, when they start changing pipes on other bikes."

Are we sure the 96's have no cats ?

[GregKhougaz]

Greg, when I removed mine, I had my friends Street glide beside me for comparison, with the core removed both header pipes dunp into a common collector before traveling through the drilled cat, with the cat in place there was a noticeable difference in exhaust volume and exit speed between the two, after the 110 was louder and appeared to have a stronger exhaust then the 96, im guessing that changing the entire system would yield very little in the way of seat of the pants performance.

Agreed, but I respect Silver-Black's opinion.  He sounds as anal as I do some time.  (Again, no offense!!)  A large part of me wants the inside of the pipe to be as smooth and free flowing as possible.  When I did the work, there was really nothing else available but to try to fit an 08 exhaust which I have seen done.  I'm happy that I seem to have a great exhaust for the cost of a bit and cores, about $150 and a fun evening hanging out with a friend to do the work.  There may be some difference by getting more material out but I doubt it is significant.  I'm very happy with sound and performance now and the other's who have followed the procedure seem to agree. 

Marty,  All the information I have is that only the 110" and CA bikes have cats.  That's been mentioned here several times.   If you were to buy a set of headers, you'd be able to look inside to confirm.  If you do, get a new set of gaskets....

[miker]

Did drilling the cat out decrease some of the heat on the right side.  Cats work with a residence time, meaning that the gas must flow through at a certain velocity in order to catalyze the hydrocarbons.

My right side gets purty dern warm, I must say.  UNitl it is "hammer time" with a D&D

[Jim Kerr]

Agreed, but I respect Silver-Black's opinion.  He sounds as anal as I do some time.  (Again, no offense!!)  A large part of me wants the inside of the pipe to be as smooth and free flowing as possible.  When I did the work, there was really nothing else available but to try to fit an 08 exhaust which I have seen done.  I'm happy that I seem to have a great exhaust for the cost of a bit and cores, about $150 and a fun evening hanging out with a friend to do the work.  There may be some difference by getting more material out but I doubt it is significant.  I'm very happy with sound and performance now and the other's who have followed the procedure seem to agree. 

My personal opinion on the subject is that it isn't critical to get every piece of the cat out.  The cylinders do not fire at the same time.  The two header pipes combine into a collector that not only forces the exhaust through the cat it also has to make a 90 degree turn to get to the left side.  The core bit boars a hole through the cat that is exactly the same inner diameter of the exhaust pipe providing a straight shot to the right pipe.  The 90 degree turn for the left pipe is already after the cat. 

Gas, like water and/or electricity, will take the path of least resistance.  I suppose there may be a bit of back-pressure or turbulence if you don't remove everything, but It certainly better than what you have with the cat in the pipe.  And you can't beat the price.