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[SBB]

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. 

Jim

I think what you have done is the best that can be done for the dollars involved.
I looked at that option and decided it wasn't the approach I wanted.
I appreciate all your pictures and video's that show what you have done.
After deciding to not drill the cat I just wanted to show that while the drilling would open it up and give you better exhaust flow there would still be restriction in the system.
Using dummy logic I felt that since the 110 was bigger than the 96, it only made sense to me that it could use better flow than a 96 which has no restrictions at all in the header pipe.




Greg

No offense!
The sign of a good man to me, is a man that's anal about his bike.

 

[Screamin]

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.



SBB

Ditto

[Jim Kerr]

I think what you have done is the best that can be done for the dollars involved.
I looked at that option and decided it wasn't the approach I wanted.
I appreciate all your pictures and video's that show what you have done.
After deciding to not drill the cat I just wanted to show that while the drilling would open it up and give you better exhaust flow there would still be restriction in the system.
Using dummy logic I felt that since the 110 was bigger than the 96, it only made sense to me that it could use better flow than a 96 which has no restrictions at all in the header pipe.

The CAM's are the limiting factor after the cat and exhaust is opened up.  The 110 engine cannot push more air than what the 2" pipe can carry (2" is the ID of the pipe where it connects to the exhaust port).  The small amount of cat remaining in the collector is not a problem.  The coring drill bit also makes the surface smooth as silk.  We tested this quite a bit on the dyno and compared results to other 110's they had tuned that never had cats.  I was right up with the best of them. 

Of course, everyone has an opinion on exhaust.  At the end of the day it is what sounds and feels good to you is what matters. 

Enjoy! 

[Fired00d]

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.

 

Ummm... I guess you can disregard my question about this in the other thread.

 
Ride Safe,
Fired00d
 

[Road Hog]

IMHO, swapping the original headers on the 110 with 96 headers is the cleanest option but coring a 1.6 or 1.5 inch hole in the cat would be so close to a clean pipe in air volume that you would have to have a very sophisticated ass to be able to tell the difference in performance between the two.  The pressure in the headers would decrease substantially with both options, as would the heat, while the airflow increased.  With the cat hole, the velocity of the air would be faster but I think the air volume would be damn close.  With the cat hole and Fullsacs, the slightly higher pressure in the header might be just the right amount of back pressure.  Don't have experience with that, tho.

This is almost a classic air flow / velocity / volume challenge..

I plan on coring and then moving on but I am not anal.  I am a "big picture" guy caught in a detail world.

Road hog

[Jim Kerr]

IMHO, swapping the original headers on the 110 with 96 headers is the cleanest option but coring a 1.6 or 1.5 inch hole in the cat would be so close to a clean pipe in air volume that you would have to have a very sophisticated ass to be able to tell the difference in performance between the two.  The pressure in the headers would decrease substantially with both options, as would the heat, while the airflow increased.  With the cat hole, the velocity of the air would be faster but I think the air volume would be damn close.  With the cat hole and Fullsacs, the slightly higher pressure in the header might be just the right amount of back pressure.  Don't have experience with that, tho.

Well said Road Hog.  The 1.6" coring bit is the diameter of the core when removed.  The outside diameter of the bit is an exact match to the ID of the pipe.  It takes every bit of cat out inside of the right pipe.  The slight piece left in the collector is a minute amount.  It was undetectable on the Dyno.  We compared my results to many different 110" engines with various exhaust configurations.  Back pressure is also a good thing.  It helps the engine with torque.  Torque is king when you are at max gross weight and want to pass someone. 

That said, however, if someone wants to buy a 96" non-cat header and then wants to go through the hassle to install it then go for it.  Personally I just don't think it is worth the cost/hassle.  It is a lot of work to remove the entire exhaust system and replace it with virtually the exact same thing when the only objective is to remove a minute amount of remaining cat material.  At that point after market headers would seem to be a better choice. 

[Screamin]

No argument at all Jim. You've got a couple of bucks in a core bit et. al. Iffn you can get a 96" header right, meaning basically nothing, then you still have the old one just in case. More than likely though the old one just joins the pile of discarded exhausts taking up room in the attic. It's all good.

[TN]

a friend of mine did this today. it’s not for the faint of heart. the info bout using a ratchet tie dow strap is the chits.
afterwords looking in the collector you can see half of the front pipe. how bout a fulsac 2” in left and 1.75 in right?

definitely cooler


TN

[ultracobbie]

Just finished removing mine.  Now it has some rumble when I put the Samson Rolled Thunder mufflers back on her.  I definetly like the looks of the original mufflers better than most others I've seen so I ordered the Fullsac 2 1/4" baffles and they should be here Monday or Tuesday. 

[Texas 103]

Well said Road Hog.  The 1.6" coring bit is the diameter of the core when removed.  The outside diameter of the bit is an exact match to the ID of the pipe.  It takes every bit of cat out inside of the right pipe.  The slight piece left in the collector is a minute amount.  It was undetectable on the Dyno.  We compared my results to many different 110" engines with various exhaust configurations.  Back pressure is also a good thing.  It helps the engine with torque.  Torque is king when you are at max gross weight and want to pass someone. 

That said, however, if someone wants to buy a 96" non-cat header and then wants to go through the hassle to install it then go for it.  Personally I just don't think it is worth the cost/hassle.  It is a lot of work to remove the entire exhaust system and replace it with virtually the exact same thing when the only objective is to remove a minute amount of remaining cat material.  At that point after market headers would seem to be a better choice. 

Jim,

They didn't have any 1.6 bits when I did mine so I ordered a 1.5, Having said that, i'd sure like to get that last .100 out of the pipe, probally won't  make a hell of a lot of difference, but the obsessive compulsive,perfectionist in me says gotta have it out.....wonder if I could sneak a 1.625 carbide hole saw in there and finish it off...not sure if that will work and may have to buy two or three of them but at least I'd have it all out...Any other ideas??? Thanks Greg

[hdbrad03]

a friend of mine did this today. it’s not for the faint of heart. the info bout using a ratchet tie dow strap is the chits.
afterwords looking in the collector you can see half of the front pipe. how bout a fulsac 2” in left and 1.75 in right?

definitely cooler

TN I like the way you think. I was wondering the same thing last night. If you restrict the right and open up the left side would the flow be more balanced. Wonder what Steve at Fullsac would think about this idea.


TN

[1abastarsmda]

Has anybody located any other sources for the 1.5" or 1.6" core bit.  I've found several places, however none even close to the price at McGills Warehouse.  I don't want to put a lot into doing this in case I end up deciding to replace the pipes completely in the near future.  I would like to give this a shot, along with the Fullsac 2.25".  I can't do much until I find a core bit though.  Anyone?

[GregKhougaz]

Toolbarn.com

SKU   Item   Qty                                         Price    Total
JD112DCC   1-1/2" Dry Diamond Core Bit    1   List Price: $60.00
                                       Your Price: $36.84    $36.84

[1abastarsmda]

That one is 9" long.  Will that be long enough?  I'm assuming that would just mean that I will need to cut the threaded rod to a longer length...as long as the bit is longer than the cat converter itself, I should be fine???

[GregKhougaz]

Yes!  It's long enough.  It was nearly identical to the one I got from McGills.  My Cat was 5.125" long.  Some have said theirs was 7" but I have not confirmed that.  You'll be fine.  Don't forget to cool / lube the bit w/ oil or WD 40 from time to time while drilling.