De-cat headpipe or buy aftermarket
#21
07-22-2011, 09:35 AM
Ultimate HDF Member
For the newer pipes with the O2 sensors mounted down low in the catalyst chamber, the cross talk issue is not BS. You have two O2 sensors, one for each cylinder, If they are both reading the same mixed exhaust gas in the now empty catalyst chamber, the ECM loses the ability to discern which cylinder cylinder needs the AFR adjusted. You can always weld new bungs further upstream to mitigate this real issue. The only way this is not an issue is if you disable the O2 function as previlously mentioned and go back to a strictly map based AFR control, or if you are of the "good nuff tune" persuasion and willing to accept less than optimal performance. If you are modifying your EFI induction system on a budget, then you get what you pay for; disabling or distorting the function of the O2 sensors by any method then you might as well be running a carburator.
#23
07-22-2011, 10:10 AM
Nuh Uh... Yeah Huh... I never said they were in the collector. Do you know what a collecter is? as opposed to a chamber. When talking about exhaust there is a big diference in being seperated and being completely shrouded from each other. Ever heard of a condition called reversion in exhaust, does this ring a bell? It happens in all exhausts, just to different degrees. I tune my own bike using exhaust gas analyisis so why don't you go ahead and tell me all about it. Y'all claim this works with no issue, but you have no means to measure and actually observe what the issue is. You do it your way and I'll do it the right way.
#24
07-22-2011, 10:22 AM
Ultimate HDF Member
Nuh Uh... Yeah Huh... I never said they were in the collector. Do you know what a collecter is? as opposed to a chamber. When talking about exhaust there is a big diference in being seperated and being completely shrouded from each other. Ever heard of a condition called reversion in exhaust, does this ring a bell? It happens in all exhausts, just to different degrees. I tune my own bike using exhaust gas analyisis so why don't you go ahead and tell me all about it. Y'all claim this works with no issue, but you have no means to measure and actually observe what the issue is. You do it your way and I'll do it the right way.
#25
07-22-2011, 10:27 AM
+1
Couple reasons:
1) Warranty
2) Here in Utah, the powers that be implemented emissions testing on cars in 1978. When they did that, they decided to require cars from 1968 on to be tested.
Since they back-dated the test to include cars that were 10 years old, then many people who had modified their emissions equipment (remove AIR pump, catalytic converter, etc) had to replace said equipment if the car failed the test.
The lesson from this is - there may not be any emissions testing done on these bikes now, but that doesn't mean that it won't happen in the future.
Couple reasons:
1) Warranty
2) Here in Utah, the powers that be implemented emissions testing on cars in 1978. When they did that, they decided to require cars from 1968 on to be tested.
Since they back-dated the test to include cars that were 10 years old, then many people who had modified their emissions equipment (remove AIR pump, catalytic converter, etc) had to replace said equipment if the car failed the test.
The lesson from this is - there may not be any emissions testing done on these bikes now, but that doesn't mean that it won't happen in the future.
Last edited by semiret; 07-22-2011 at 10:47 AM. Reason: spelling
#26
07-22-2011, 11:09 AM
I sent my head pipe to American Custom. They removed the CAT and refinished. It was fast and about half of what a new head pipe would be. Good people. An option to consider. I also picked up a set of FuelMoto Jackpot slip-ons from a forum member. I'll install this weekend and report back.
#28
07-22-2011, 11:29 AM
I posted a few weeks back that our dealer recommended we get rid of the cat and substitute with gutted pipes. With no AC change and leaving stock mufflers he said the ECM would compensate. Warranty is not impacted.
We did that, 3500 k ago, bikes runs great. Plugs look great. Warranty intact.
2011 CVO RG
We did that, 3500 k ago, bikes runs great. Plugs look great. Warranty intact.
2011 CVO RG
#29
07-22-2011, 11:43 AM
Banned
Join Date: Oct 2006
Location: Bella Vista Ar.
Posts: 186
Likes: 0
Received 0 Likes
on
0 Posts
#30
07-22-2011, 11:46 AM
Stellar HDF Member
Lots of people here have gutted their stock head pipe with absolutely no issues including myself. The crosstalk some talk about is complete BS. Some of us are on a budget and gutting the stock head pipe is lots cheaper than buying a $450 head pipe. The gains with an aftermarket head pipe are minimal at best. The stock head pipe functions great without the CAT. It's a good design. It cost me $25 to get it welded back together plus the cost of new exhaust gaskets. So for less than $50 you have a great head pipe. If you have $450 laying around then by all means buy a new one.
