Even though I've only had the bike for less than a week now I've done a fair few tweaks to it thus far. In the last 24 hours this has included new grips and - more importantly - the drilling of the plugs in the stock exhaust baffles.

Now, if there's anyone on here who still has stock pipes on their Sporty - YOU MUST DO THIS MOD!

Really, the difference in sound is night and day, and for such a quick and easy mod you'll be amazed.

I found the stock exhaust to be extremely quiet, especially when cruising on part throttle which made the Iron sound like a mixmaster. After the simple addition of a 12mm hole in the end plugs of each exhaust baffle the exhaust note changes to a deep burble both on and off throttle. Its raspier and meatier, and as a first time Harley owner I'm actually very happy to have the sound I thought the bike should have had from ther showroom.

For the uninitiated, essentially this mod entails drilling a single 12 - 18mm hole the the small 30mm diameter end bungs that you can see if you shine a torch into the stock mufflers. The steel is very thin and easy to drill through, while some others have taken to knocking these bungs out completely. This, alegedly, will result in a whilsting sound at idle, so I decided to start with 12mm holes and so how it went from there.

The biungs ar about 25cm into each muffler. To drill them I went to Bunning and bought an extension for my 240V drill as well as a set of step up drill bits as shown in the pictures. I wrapped the shaft of the drill extension with masking tape to create a 30mm ring that would centre the drill in the exhaust. I also taped the drill bit at the 12mm marker so that I would know when I'd reach this diameter hole.

Honestly, it is an incredibly easy and satisfying mod if you can't afford to buy new pipes. After all, the Screamin Eagle pipes are silly money in Oz when most of us just want to S-O-U-N-D!

 

What a shame you haven't got any standard pipes to put back on it when the blue gang do you for excessive noise!!!! Hahahaha...only joking...enjoy the sound...ride safe.

What's that officer? Noisey? Nooooo... this is the stock exhaust from the factory!

Lisa, I guarantee that if you heard the improvement you'd want it done ASAP.

I think spending all that cash on a Sporty is madness. What's the point of buying a $13500 bike just to put another $3000 worth of over priced Harley branded stuff on it?

Why not get get the Nightster with the 1200?

Gday Danom,
Drilled the pipes on my wifes Iron Yesterday. Awsome trick, sounds good and has a bit more power.
Cheers.

Generally when I do mods to standard gear I look around on ebay and the like for another set so I can keep the originals intact. Most of the standard gear sell cheap as people are upgrading anyway.

HELP! Tried this modification last night, however, on the second exhaust, when removing the drill the drill bit detached itself as is now inside the exhaust (on the other side of the plate that has a 12mm hole in it).

How do I get it out?

Could it get sucked into the ehgine? 

Pipes are only slip ons, should be able to remove the tail end and the drill bit that way..........unsure if there are additional baffle plates behind the ones being drilled out ?

Thanks Grand Tourer. Has anyone removed the slip on? As well as the slip on clamp, there are 2 bolts that hold the body of the slip on. Those 3 aren't a problem. But then there's a round chrome "spacer" as well. How do I disconnect that bit?

I have a sporty nightster, my slip ons only has the three you said, the clamp is just like an exhaust clamp, some pulling and twisting should have it off. Not sure what your ride is though, some others may be able to comment further on the spacer.

Cheers.

It's an 883 Custom and there is definitely a round chrome bit that goes from the slip on across to a rod that comes of the black mounting bar.

The collar or chrome bit is a flared pipe end, acts as a locator to a dowel (like a solid bar or branch off the mounting bar), it has a graphite like ring or gasket inside the collar or flared end. There is no fastened connection (just pulls away), however, you may need to loosen the nuts on the exhaust at the barrel to allow movement enough for the flared end to clear the dowel............As I recall I also loosened the heat shield from the exhaust pipe to access the nuts (use a tube socket on the stud nuts).

Yeah, just loosen everything off and wiggle it patiently, and you will get there. And once the drill bit is removed you will see daylight down yer muffler. You would think it would be louder than it is, but it is all good.

See Ya
Birch

Thanks Birch and Grand Tourer. It is all fixed. I removed the heat shield, removed 2 bolts and loosened 2 bolts and then wiggled the muffler off.

The learning is that, if like me you buy the Sontax 3 piece step drill set from Bunnings (with quick change shank), you must use the 6-20mm bit and tape it at the 12mm step. If you use the 3-12mm or 4-12mm bit you risk losing the bit inside the muffler.

Using an iPhone app, I can report that the average dB at tick over is now 105. Before the mod it was 102. The downside is that I have lost a noticable amount of engine breaking. Did others experience this? Does the same thing happen with a Vance & Hines or Screamin' Eagle slip-on?

has anyone considered putting a thread in hole so that if gestapo bung you you can fit a stainless bolt in thread and quiten some?is possible?

Since the plug in the baffle is a thin piece of metal it isn;t suitable to threading it to do this. The exhaust isn't so loud that you'll get pinged anyway in my view.

thanks Damon wasn't sure about baffle thickness will just drill 12mm hole and see what comes of it. dealer gave pipes as part of deal bit too loud for me must be getting old

Damon have drilled out with 12mm sounds ok what size did you finally settle on that wasn't over the top noise wise?

I just drilled mine at 12mm as this is what the majority of guys on XLForums had been advising. Many have removed the bungs altogether but after this is done most have reported a whistling sound at idle with little benefit in sound. Given this I have not trialed larger holes or removing the bungs and I am more than happy with it considering it was a near free mod. I will consider aftermarket pipes after the 1250 conversion.