punching out exhaust

[Macrider]

I am also on a forum for Honda cruisers (shadows) and a lot of guys on that forum will do what is known as a "hole saw mod" or "rebar mod".
What this is is drilling out the baffles or punching a hole or 2 into the baffles with a long length of sharpened rebar.
It gives the bike more rumble and also increases power a bit.
Has anyone tried this with the R3T? Or any of the other rockets as a cheap alternative to expensive aftermarket exhausts?
Would it need a retune after doing that?

 

[Manic_Mechanic]

I did that before I got the Jardines. Nice sound and only did a 12 minute tune afterwards. More of the packing migrates out over time. I still have the drilled out set CHEAP!

 

[STRIPES]

better sound

If you will look a few inches from the end of the pipes on the inner bottom side, there are a couple of chrome rivets. You can use a cold chisel and cut the heads then punch the remaining through. Then make a hook out of something strong like rebar. Bend the other end so you will have something to bang on with a hammer. Slide you baffle remover tool into the baffle until it reaches all the way through. Beat on the exposed end till the baffle comes completely out. Remove fiber glass. Also while it is exposed, drill several extra holes around the flat restriction plates on both ends of the baffle. Reinstall the baffle lining up the original holes where the brad were located. Install a self tapping screw. It will hold just fine. Voila! A very nice deep throated sound! Re-map.

 

[HellFire]

I stopped after just drilling holes in the back plate around the exhaust hole, didn't change anything in my opinion. I think you would have to go further than I did to get any results.
Just drilling did change the sound on my old Yamaha Seca, so it works on some bikes.

 

[STRIPES]

You are right. I changed my post to read more clearly. You need to drill holes on both ends of the baffles.

 

[Micksan]

I have been doing this punch out for a umber of years on different bikes. This as with all mods the basic rule applies that what you do at one end you must balance on the other end.
When you drill out the muffler you are relieving back pressure, and leaning out the mixture .If not corrected it can over heat the engine. With the old Carb systems it was a simple matter of changing the needles , and plugs.
The lasyt bike I punched out was my VTX 1800 when I triked it out. They had increased the length of the pipes using the stock mufflers. This increased the back pressure making it run like crap, and dropping the MPG way down. I used a 1/2 inch drill with a 24 inch drill extension. I started off with a single 1/4 inch hole coming from each end. Then took it out for a ride.Then repeated it. Performance started to increase . Got it back up to where the performance and MPG where doing good , and sound did not rattle my neighbors windows. Plus I do not have any backfiring which indicates to lean of a mixture.
In short if you are going to do it take your time.

 

[HellFire]

You are right. I changed my post to read more clearly. You need to drill holes on both ends of the baffles.

Yeah, I didn't know there was another plate back there till I removed the stock parts for the TOR's and looked in the holes.
It was another "DUH!" moment.

 

[STRIPES]

Yep. Drilling both plates makes a really nice difference. Utilizing the self tapping screws allow for a quick complete removal in case you want to raise a little hell for a short period. I wouldn't recommend leaving them out for many miles though.