Bonneville America Forums Forums Technical Forums Exhaust drilled stock pipes

I drilled four 9/16 holes in my outer baffle and two 9/16 holes in the 2nd baffle which is about 12 inches from the first. I started with two holes then listened . Then continued on untill I was happy with the tone and volume. They sound much much deeper but only a little louder. I'm very happy with sound and the price was outstanding.FREE I figure if I did'nt like it I could always buy some slip-ons. Anyway no change in performance , but no other changes either same jets,airfilters ect... This is a brand new 07 SM only 1000 miles. Well if you just bought a new bike and can't quite afford new pipes try this while you save up, at least it does'nt sound like a saws-all anymore.

I'm glad I'm not the only to have tinkered with the stock ones. I have completely removed the back baffles on both my Americas and I'm completely happy with the sound they make. And as you say it's free!
And I haven't needed to rejet, or play with anything else and they both run fine...just ask anyone who trys to keep up with me!

How did you go about taking the back baffles out? With a drill or punched out? I'm new at this so I'm a little hesitant to just start in on them. Thanks.

This method only really works with the slash cuts...

Well...to start with have a very nice dad.... or be brave enough to do it yourself.

I told him what to do and he did it. By the second time around he was better...

Get a drill - long enough to hit the baffle plate and not catch the end of the pipe with the drill. Go round the plate and make little holes all the way round and then knock the plate out. Get a little stone (like the kind you get for a dremel or indeed in a dremel) and grind down the bits that are left. That way it looks tidy inside and makes the pipes a little louder.

thanks for the advice...my dad can't do it so i guess i'll have to do...got the holes and the center pipes knocked out...now all i have to do is make it tidy...think it would sound even better if i could get to that second baffle!...thanks again.
leo

I did all my baffles with an air hammer and angled exhaust chisel. Other guys have done it with a piece of rebar with a cutting edge ground on the end. Be careful there is mesh all the way around the inside of the pipe with packing you don't want to catch that. I have done I think 12 sets now.

If you remove the baffles DO NOT remove the reducer cone at the header end or you will lose all your bottom end torque.

For the second baffle on slash cut pipes, get a 2 foot long bar or pipe and give the second baffle a few hits. It will just break off inside. Then grab a coat hanger wire and bend a hook onto the end. pull ot the second baffle. very easy. For the third baffle I have welded a 10mmm drill bit to a 3 foot long bar and drilled 4 holes in each of the third baffles. Sounds good, not loud but very deep rumble. Love it. I am stopping there for now. Not sure what 3 baffles removed will do.

I just drilled mine.i have some funny sounding popping????I just got my ai removal kit,i will put that in and see if there is a difference.

no more popping,AI removal did the trick!!!

I am considering just buying some better sounding pipes when I pick up my bike. All this modification really makes me apprehensive. Do any of you all have before and after pictures of your mods? I would love to see them before I do this to my bike if I decide not to get the new pipes. Plus it would really help my comfort level.

I just removed the first baffle.I drilled around the rear plate with a small drill bit,then went back with a much bigger bit and that made the holes intersect each other and then i took a wooden dowel and knocked it out. it left some little jagged edges in there you can grind out with a drimmel or just leave it cause unless you get down and look in the pipe its really hard to tell.the sound is not loud,it just gives the pipes a low rumble.pretty cool actually.

also i removed that tube before i drilled to make it easier to get inside with the drill.just use something round that fits inside the tube and start bending it up,down,and side to side and the weld will break and pull out the tube with some pliers.once i had the tube out a 1 1/2" or slightly bigger hole saw would have worked,but i was to cheap to go buy one.

I had that popping after the dealer removed my AI kit. It turned out to be a loose hose.

The pipes do not look any different since you are removing the baffles from the end and inside the pipes. You would not know I have done anything to my pipes until you hear it give a growl when I open the throttle. Its not too loud though.

Regards

Derek

On my 04 TBA, I took a rebar and inserted it into the center pipe and wiggled it hard until it broke free. Then I used a 2.5" hole saw to remove the disk. Real easy. I like the sound of just one removed, but I want it a bit louder. If I take that second one from the rear out, would I need to rejet sitting at 1000FT above sea level? If so what jets are in it and which jet would be recommended?

Thanks,

Aaron

try this site http://www.dinqua.com/
it has a jetting calculator on it, plus a lot of other great mods info .it belongs to one of the moderators of this site. jeez i cant remember the stock size at the moment but i,m sure someone will pipe up (pun intended)soon

I have the Triumph short Offroad pipes and have just takin the first baffle out together with the dampingmaterial.
Is it really 3 baffles in these since the second one sits pretty deep inside the pipe and it doesn´t look as if there could be room for another one ??
Also should you leave the centerpipe which sits between the first (which I removed)and the second baffle?

Hey guys,

first clip, my bike stock, second part is with the rear most baffle out a 1.5" hole drilled with a hole saw.

First baffle modified

Second clip: three half inch holes in the second baffle plate. Second baffle modified

That was two years ago, they get louder as time goes by. But awesome volume, but not obnoxious, great tone...you decide.

I modified airbox later with a partial gut and dealer changed needle position. Dealer was fine with the mods. That was when it had 2000 miles on it...I have 23,000 miles on it now. Still strong and ready for the next 23,000 miles, it's not going anywhere soon.


eddy

Sounds good i may have to drill the second baffle.

I need a little more noise. If I drill out the back plate with a 1.5 inch hole saw and remone the tube will I loose backpressure or performance ??

no you will be fine. You can remove all the baffles and still have enough back pressure as long as you do NOT remove the reducer cone at the header end of the mufflers. If you remove baffles remember to rejet.I removed all my baffles and installed the freak ,AI removed,rejetted and last time I dynoed it I was at 65HP

Made a mistake on number of holes. I used this hole saw made by MikeSr,




a 1.5 inch hole in the end plate (around teh tube), tube removed, 1.5 hole in second plate tube removed and 3: 1/2" holes in second [plate, some do four, I messed up on placemnt of first hole so kept it uniform both sides.

Shot a little heat paint up there to dress it up looks nice for those who feel compelled to lay on the ground and look into my pipes!