removing the baffle?!
 

ok, i know that the muffler serves 2 purposes to provide backpressure and noise reduction. so, the baffle only provides for noise reduction and does nothing for backpressure, while desrupting the flow of exhuast in effect klling some HP, right? To be honest i'd like to get rid of the baffle mainly for noise purposes, but hp gain is a plus. Please let me know if my logic is flawed, usually is :o). Also, is it at all possible to get rid of the cat converter for additional power gain? I apreciate any feedback on this guys, thanx!

RE: removing the baffle?!
 

I Drilled out my baffels with a 1" hole saw down each pipe. Sounds alot meaner, a bit buzzy at higher rpms but better thatn nothing at all. her's a link that will give you dyno results of drilled out pipe on an 05 CBR 1000rr http://hooliganbiketech.dynup.net/ho...frameindex.htm
Hope This helps

RE: removing the baffle?!
 

I cut the exhaust open at the topand cut a big hole in the baffle opposite the intake pipe then welded the can back up i also took away the vavle completely and welded up the holes sounds great !

RE: removing the baffle?!
 

I searched that entire site and could not find a single article talking about how to drill or mod the exhaust. I found a sound clip of the exhaust that had been punched out, but nothing about how to do it.

RE: removing the baffle?!
 

I did what that guy up there did. Drilled some holes and the bike does sound meaner. I didn't drill 1inch holes mine are half an inch. Couldn't find a unibit that would fit on a 12in extension so I went with the 1/2 in and drilled 2 holes on each end of the tail pipe. Sounds great. Wonder though if I had drilled a larger diameter hole if it would sound deeper.

There is a slight increase in vibrations, didn't like that but its not enough to were it is bothersome. Just ever so slight. Expected I guess when you are making something louder and having a deeper rumble. Beats spending $500- $600 for a slip on. I did it because I wanted the sound not necessary a performance increase, the bike has plenty of power, it was just too quiet.

Did alot of research on "how and if" drilling holes into the tailpipe baffle. If someone knows something that I have yet to experience by doing this and have screwed something up, please let me know.

RE: removing the baffle?!
 

Squire, click the DYNO RUNS link. Read that article and It'll give you details and dyno charts. As far as the drilling, I went to Home depot and got a 1" drillbit and a 18" extension. Then just stuck it down each exaust port (on the can) with the bike running, to blow out any shavings. Yoou could probally get away with a 1 1/4" bit though, just measure the diameter of the ports.

RE: removing the baffle?!
 

I just put a yoshi rs5 carbon with carbon tip on mine, drilled the riverts out and took the baffle out...sounds soooo much better!! I got all the info to do it off this forum...Thanks guys :)

RE: removing the baffle?!
 

I couldn't find an extension that would hold the 1 inch unibit so I got the 1/2 inch and drilled 2 holes on each side. Wondering if I should drill a 3rd hole on each side to increase the hole size so it looks like a flattened circle sorta and am wondering if that would make the bike sound deeper and or louder.

Anyone have an idea if the size of the hole would make a difference in the tone or sound of the exhaust when drilling out the baffle?

Anyone have experience with this, start out with a smaller hole and then increased the size of the hole and noticed any difference?

When I drilled the 1st hole that made a noticable difference. When I drilled the second hole I really couln't tell. Just wanting to know if someone already has done what I'm about to do. ( increase the size of the hole )

This mod is definitely worth doing to me. Sounds much better. I was surprised how quiet the 1000 was compared to my 600. And it cost way less than a new slip on.

RE: removing the baffle?!
 

All you ever wanted to know about drilling your exhaust.

BTW Hi there, I'm Paul and I have a 2 wheel addiction! [:-]

RE: removing the baffle?!
 

Thanks for the link. Great info but I don't know if drilling more holes makes it better or deeper sounding. There seems to be guys that drilled 1 and 1/4 inch holes and them some that drilled more smaller 1/2 inch and smaller holes.

The sound bites from the repsol with drilled holes and with the aftermarket pipe really are different. The aftermarket sounds better much deeper sounding.

Looks like I will try bigger holes just to see what it does and if it is not to my liking then I'm going with an aftermarket pipe. Geez there are so many to choose.

RE: removing the baffle?!
 

This is an update for those that are interested. I heard about the drilling holes in the baffle wall. Gave it a shot with a 1/2 inch hole. If you look down the tailpipe of the cbr1000rr you will see the wall and there are 2 indentions on the wall. Perfect for the half inch unibit, so the bit doesn't wander around.

I drilled 1 half inch holes on both sides of the tailpipes. The bike sounded louder but it had a sport tuner type sound to it, which I didn't like too much. ( you know like an import car with an aftermarket muffler )

So I decided lets drill another hole in the other indention. Couldn't notice a huge difference but sounded a little less whinny, if that makes any sense. Decided to place another hole to increase the size of the holes I put in already. Tried to drill to where the extisting holes would come together to make one big hole. Sounded a little deeper and less like an import car. Great lets go for the 4th hole on each side. Didn't come out nice it looks sloppy if you look down the pipe. But it sounded better.

Rev rev rev and it sounded pretty good. Held it at certain rpms and you here a fluttering. Its not a steady sound. It goes in and out, choppy. Was concerned and thought I screwed something up. Then listened to a twobrothers exhaust and a akropovic and they did the same thing so not worried anymore.

Great mod for the price and sound. You just have to have the right number of holes and the right size. The only thing I don't like is the increase in vibrations felt through the seat and handlebars. Before I drilled holes I could ride all day almost and feel fine. Now I feel it in my hands and azz when I'm done riding.

May go for a akropovic it sounded a little deeper. The two brothers sounded almost like doing the mod. I forgot to check if those pipes produced more vibrations throught the seat and handlebars. Anyone know if they do?

RE: removing the baffle?!
 

I also want to know the same thing !

RE: removing the baffle?!
 

Drilling a baffle is lame. The noise it makes sounds crappy to a knowledgeable ear, may actually cause a loss of power, and is a generally squidly thing to do to a nice bike..

RE: removing the baffle?!
 

I dont see why it would be squidly when some companies sell them w//o baffles from factory.

RE: removing the baffle?!
 

I don't think it's squidly, just different options available to do different things. It's not like putting chrome fenders or a crown on the dash. Just something to try to make a stock exhaust just a little louder than from how it came from the factory.

It depends on which bike, drilling holes in some just doesn't sound good but on others it sounds ok. On my liter bike it sounds ok. Not as deep sounding as a akrapovic but still lets you know the bike is on and their sitting in traffic. Its not obnoctiously ( man my spelling sucks ) loud either to where it frightens old ladies and makes people gowtf and spill their coffee.

I did this to my bike so a friend had to try it on his. On his 600 it sounds weak. A high pitch rumble. He decided why not since he's getting ascorpion anyways. The mod only takesabout 10 min. Another friend tried it on his cruiser, that tookafew hours but it sounded much better.

In some cases it sounds good in others it doesn't. I guess it depends on the bike and muffler system. I wouldn't do it unless you plan on getting an aftermarket pipe anyways. That way if you do it and like the sound then you saved yourself some $$$. But if you don't like it, hey your gettin a pipe anyways. I like it but I think I'll gowith a akrapovic only because it sounds deeper at idle. When you rev it up they all sound kinda the same screaming.

RE: removing the baffle?!
 

You don't get a loss of power drilling out your baffels, you gain dyno proven power! And some of us don't have The disposable income to get a new pipe yet. Sure I could get a yosh s/o but driling the baffels gave me the same power. I'll wait till I got enough for a nice acro F/S .

RE: removing the baffle?!
 

My CBR now wants an "Akropovic Exhaust ", thanks to this thread. I'll be eating mac&cheese for months now. When time comes to purchase, I'll be looking on this board for resources ( and recipies ).