What you see vs. the reality of the sound is different. Again, I have a video of me starting the bike (stock 103) with NO mufflers and it is extremely loud.

 

There are a lot of times that it is hard to get the facts here.

 

Ditto, I found this to be the case with my '09 RK (a Calif bike so it had a CAT in it). I'm running the stock mufflers with a set of V&H Powerduals, SE Ventilator a/c and a PCV. Just replacing the head pipes makes a noticeable improvement in the sound and tone of the exhaust. I will probably just stick with the stock mufflers

 

MY 2011 headpipe had the cat professionally removed and rewelded.

I've had it for sale on here for a few days already, and not a single hit back.

wonder why??

~Joe

 

Probably because you can do it yourself for about $25

 

Not a single hit because a "gutted" pipe may and may not work. I have yet to see one work correctly. The OEM sensors will and can get wrong gas flow information.

The issue is definitely there. It really depends on the restriction of the muffler. I had (2) (2010 and 2011)bikes back to back tuned same day. One had SE muflers with a gutted cat and the other had Rinehart mufflers with the gutted cat. These cats were removed by Amercian !!! someone, cut, gutted and re-welded. With the tuning all done, and in open loop the Target and Actual AFR/Lambda values line up spot on. While running the bike with cruise on and in closed loop I could see and verify that one of the cylinders was tuning/running itself leaner. Not right away but the longer I ran the bike the leaner it got on the one cylinder. The SE muffler was bad enough that I talked with the customer and we/he decided to open loop the AFR/Lambda table eveywhere. The other bike with the Rinehart mufflers also showed the same lean out but not to the same extent as the SE muffler. The Rinehart was "border" line in my opinion so I left it up to the customer and he chose to go open loop. I ran it on the dyno in cruise for 10- 15 minutes and saw the cylinder Actual AFR/Lambda values drifting from the Target, I have no way of knowing how far it will drift when the bike is on a 2000 mile trip , in other words how lean will it get? Will it get lean enough to cause a heat problem, I have no way of knowing??

I look at it this way, I would not "gut" the cat if it was my bike. Let's see I spend $25-$40K for a bike, a new head pipe from FM or FS is $400-500, and it fits and looks just like stock when done. Seems like a no brainer to me but then this is JMHO.

Just as a side note, the bikes I tune that have the FM or FS head pipe when cruising with the bike in Closed loop the Target versus Actual AFR/Lambda data is always spot on. I have seen no dift in either of these head pipes.

 

I know what you are saying Ed, but I agree with others in the "Drill Baby Drill" thread about the sensors being contained with-in there own pipe (exhaust) from the motor. I can't see where the "cross talk" would come into play from just gutting the cat. Matter-of-fact your (fullsac) picture shows proof of this separation and with the cat it would even be worst with exhaust backing-up creating cross talk for the sensor's readings. That sensor reading is taken immediately as the exhaust passes by, which shows it with-in the pipe from #2.
I respect all you write, sounds like you know what's going down, but maybe this was another problem all together, you know how stuff gets twisted sometimes.
I agree if the sensors where contained with-in their own complete pipe, like JackPots, etc it would be better......separate pipe sensors, no doubt then!
Carry-on bro, just my personal thought.

 

I hear my 02 sensors talking to each other all the time now after gutting the CAT. They usually say " damn it's a lot cooler with that Cat gone". But seriously, I have had no issues with this what so ever.

 

I recently purchased a complete 2011 RK exhaust for $60 (the give the stock stuff away) and sold the mufflers for $40. I removed the CAT (about 2 to 3 hrs) and spoke to Jamie at Fuel Moto. He set me up with the stage one kit, 4" Jackpot mufflers (sound great) high flow air filter and a Power Vision. I went with a Power Vision so I could keep the stock O2 sensors and it could correct the ECM's program to prevent the above issue. I questuined the above issue myself as 09 bikes had no convertor and the chamber is empty. Their O2 sensors are by the cylinder exhaust ports. Jamie assured me their would be no problem. 5 or 600 miles later, the bike runs well , no popping or discoloration to the mufflers. Has a little more power and is smooth.

 

It worked great for me.

~Joe