I am sure this has been answered, but after reading and searching for 75 minutes I gave up on finding the thread(s).
On my 11 and 16 Limited, I removed the stock header and gutted the Catalytic converter and reinstalled for an improved header. Can this be done to the 2018 Limited? I considering buying the 2018 and need to know the exhaust options.
Thanks
Quote from: HarleyHiwayMan on April 27, 2019, 04:56:28 AM
I am sure this has been answered, but after reading and searching for 75 minutes I gave up on finding the thread(s).
On my 11 and 16 Limited, I removed the stock header and gutted the Catalytic converter and reinstalled for an improved header. Can this be done to the 2018 Limited? I considering buying the 2018 and need to know the exhaust options.
Thanks
Yes. And they work extremely well.
And it is easier to decat an M8 headpipe than the TC head pipes!
Awesome, thanks guys. I'm into it
Does the bike have to be retuned?
Quote from: alanm2002 on April 28, 2019, 05:37:31 PM
Does the bike have to be retuned?
You will get differing replies to that. Maybe some will chime in, be an interesting read.
Yes it needs to be tuned. Anytime air flow changes, fuel requirements change.
Thank you !!!
How are you folks removing the cat? Perhaps a photo ?
Durwood, what is the performance difference between the Decatted stock head pipe and some of the aftermarket head pipes such as Fuel Moto's 2-1-2 and the Fullsac MX pipe?
Quote from: Sunny Jim on April 29, 2019, 04:29:46 PM
How are you folks removing the cat? Perhaps a photo ?
Cut the header, press the cat out and reweld.
Quote from: lonegoosehonking on April 30, 2019, 02:39:17 AM
Durwood, what is the performance difference between the Decatted stock head pipe and some of the aftermarket head pipes such as Fuel Moto's 2-1-2 and the Fullsac MX pipe?
little to none on most builds
Quote from: Durwood on April 29, 2019, 04:41:23 AM
Yes it needs to be tuned. Anytime air flow changes, fuel requirements change.
Realize he's asking about a M8, but on the Twin Cams any tuning issues with the decatted headpipe? Thought I read somewhere The O2 readings "confused" each other.
Quote from: cheech on April 30, 2019, 07:05:05 PM
Quote from: Durwood on April 29, 2019, 04:41:23 AM
Yes it needs to be tuned. Anytime air flow changes, fuel requirements change.
Realize he's asking about a M8, but on the Twin Cams any tuning issues with the decatted headpipe? Thought I read somewhere The O2 readings "confused" each other.
I personally have never seen any evidence of cross talk on my dyno, and absolutely zero factual data has ever been posted to support that theory.
I use them all the time, both Twin Cam and Milwaukee 8 and they always do well.
Sensor location is much further upstream than with the twin cam head pipe.
On just decatting the pipe on a all stock 107, what gains can be expected. I seeing a lot bigger gains on a all stock twin cam then the M 8's. It seem like the M 8's cats flow a lot more then the twin cams. The other thing I notice is the stock air cleaner holds the M 8's back more then the twin cams.
Quote from: joe_lyons on May 01, 2019, 06:42:43 AM
Sensor location is much further upstream than with the twin cam head pipe.
Agreed. But I still haven't witnessed cross talk on the TC pipe.
Quote from: BUGLET on May 01, 2019, 07:03:35 AM
On just decatting the pipe on a all stock 107, what gains can be expected. I seeing a lot bigger gains on a all stock twin cam then the M 8's. It seem like the M 8's cats flow a lot more then the twin cams. The other thing I notice is the stock air cleaner holds the M 8's back more then the twin cams.
I didn't see any gains on a stock 107. Air cleaner? Yes, and I posted graphs in the M8 testing thread a couple years back.
I would like to ask if anyone is de-catting the M-8 for the sole purpose of lowering the exhaust temps. Got a friend who has a 2018 model and is complaining of high heat on his leg. Dealer installed slip ons but I have no idea if it's been tuned. I'll have to ask.
Quote from: motorplex88 on May 01, 2019, 07:36:08 AM
I would like to ask if anyone is de-catting the M-8 for the sole purpose of lowering the exhaust temps. Got a friend who has a 2018 model and is complaining of high heat on his leg. Dealer installed slip ons but I have no idea if it's been tuned. I'll have to ask.
In my estimation this is the primary benefit of the removal - the cats flow just fine and motors can make power with them
Yeah, I kinda figured that would at least be ONE of the main reasons. Just found out he has the slip on's but everything else is still stock. Sez he will just have to put up with it because of warranty issues if anything else gets changed. :banghead:
Quote from: Durwood on May 01, 2019, 04:41:54 AM
I personally have never seen any evidence of cross talk on my dyno, and absolutely zero factual data has ever been posted to support that theory.
I use them all the time, both Twin Cam and Milwaukee 8 and they always do well.
Thanks! Figured was BS.
Is there anything out there that you can pull the cat. and not affect the warranty.
Quote from: hd06 on May 01, 2019, 04:18:04 PM
Is there anything out there that you can pull the cat. and not affect the warranty.
It is an unauthorized modification, so technically warranty would be void. And it is a federal offense.
Just sayin'.
Take a stock headpipe with muffs and compare the exhaust note to a decatted pipe with the same muffs. Much different. And it's not about what you gain it's about what you lose in the form of heat. I don't even take the time to press them out I just weld in a new piece of tubing.
Quote from: BVHOG on May 01, 2019, 04:34:19 PM
Take a stock headpipe with muffs and compare the exhaust note to a decatted pipe with the same muffs. Much different. And it's not about what you gain it's about what you lose in the form of heat. I don't even take the time to press them out I just weld in a new piece of tubing.
That would certainly speed up the process! I assume you can just use common 3" or 4" exhaust tubing, oblong it and weld it in, care to share you secrets?
I have cut the head pipe in two and taken a crappy drill bit, pliers, chisels and punched the cat out, then taken a grinder and cleaned out the inside of the pipe , then weld back together, but it is an hour or more to do a good job.
Cat pipe is round on the M8
Ahhh, ok!