I have drilled most of my recent model bikes, the clutch side sounds ok, but doing both sounds real good, esp if you put the new pipes on an old Evo, since the newer pipes were more freer flowing to compensate for the Cat restriction.


here's how I plan to do the 2017 tomorrow:
https://www.hdforums.com/forum/exhau...e-drilled.html

here's pic of the 2017 pipe, which really indicates the MoCo did us a favor: you stay stock (ok), drill one pipe (prolly still ok) or drill both pipes and get a decent sound.

to my mind, this makes the OEM mufflers actually something better than true scrap metal, if you can use these long term.

is there enough interest that i should do sound clips & drive by's stock/one pipe drilled/two pipes drilled, or not?

 

Yes. I would be very interested in sound clips before and after. Please post them. I'm on the fence with drilling mine out or spending money for a set of headers.

 

I have just seen my future, ... .. and I like it !!

 

M8 pipes are really quiet compared to stock twin cam so you have to at least remove the inner baffle pipe completely to get a nice sound.In your photos you can see the end of the baffle pipe which is firmly welded inside the tailpipe outlet.First you have to detach the silencer and clamp it on the workbench.Cut all the way around the outlet pipe without cutting the baffle pipe or end cap.You could use a small rotary cutter,gas,plasma or as I did,an arc weld cut.Whaterver you do do not try to chisel or hack it out! The outer pipe and baffle have to drop out of the inlet side which they won't do if distorted!
A friend took this one further and cut around the end cap,removed it and the muffler padding! It was loud but so reverberating ugly he paid to have the padding and end cap refitted.

 

well, I did mine tonight, they are perfect for the price.

sound good, not too loud, but should be enough to let a cage know you are there.


my vids wont load

 

the trick is to go slow and steady, you want to cut complete thru everything, so that you don't have a ragged edge (that you can't get the piece back thru)

you should use a cheap regular drill. that big drill tried to break my arm, and the dewalt hammer drill broke the teeth off the bit.

just use a cheap drill & go slow, takes 10 minutes per side.

i would buy two of the bits when you go, in case you break the teeth off one.

i think the bits are ~20$ each, there's no reason NOT to do this on a stock bike.

i think it is A very wise decision for the MoCo to finally make an OEM muffler that doesn't' instantly go in the trash, and isn't part of the "Harley Tax"
this is really something many of us can live with

 

Not worth the headaches it going to bring me when and if i need warranty work. I am going to give it some time someone will come up with louder pipes and upgrades for the M8s

 

You can upload the vids to YouTube, then just copy/paste the web address here. Thanks for sharing your efforts.

Personally, so far I find my 114 Heritage to be better sounding than previous stock Twin Cams. I don't feel the extreme urge to open it up the way I've always done in the past. Given time that may change. Appreciate the thread. Thanks.

 

I bought a 42mm hole saw from a hard ware store and drilled the end cap . A 42mm hole saw fits into the end cap hole perfectly and you only cut out the crimped part of the baffle It sounds little throaty but NOT LOUD

 

My already recommended procedure is to cut all the way around inside the exit pipe about 1 1/2" inside.Thereby avoiding the hard and heavily welded 10" baffle pipe which will slide out as a complete unit from the inlet end.If you leave most of the perforated baffle inside it will coutinue baffling the sound! The proper result can't be described as noise,it is a deep rumble!You will also avoid the potential of serious injury drilling inside a pipe with a hole saw!