Dunstall mufflers

cyclon36 · Post by **cyclon36** » Fri Jul 02, 2010 12:52 pm

Looks good. I've been eyeballing these for my rebuild. Any feedback on how the sound compares to the stock setup (louder/quieter/same)? I don't mind a bit louder but I enjoy long rides and don't want to come home with a headache.

Spargett · Post by **Spargett** » Fri Jul 02, 2010 1:12 pm

I found they sound great. I opened them up a little bit to give it a bit more growl.

Vince Lupo · Post by **Vince Lupo** » Wed Jul 07, 2010 3:31 am

Mike -- got any closeup shots of that rear mounting bracket arrangement?

Just as something to keep an eye on: I went through three sets of EMGO Dunstalls on my bike. Mind you, I was using the EMGO Dunstall Decibal repros (different outlet shape, but basically the same), but they have one weak spot -- the facing plate on that mounting channel on the backside of the muffler. The metal seems to be very thin there, and I had three of them fracture in the same spot. The fit and finish of the mufflers is excellent (for the money), but at least in my experience that mounting channel area is their one area of weakness.

Mike Mullins · Post by **Mike Mullins** » Wed Jul 07, 2010 5:25 am

Here are a couple of pics I did recently. You are right, this is a weak point. I think fabricating a bracket with two attachment points at the muffler would help. ( The bike is now apart for a new cam chain, and trans work.)
Mike

teazer · Post by **teazer** » Wed Jul 07, 2010 10:19 am

Back in the day we used all manner of pipes on our bikes and loved the extra sound level.

IIRC there was an article in a magazine that suggested that stock mufflers worked best on the street - they were talking performance rather than noise pollution.

Does anyone have any objective data on the performance of their bike with stock versus aftermarket pipes? I know they sound good and that makes them feel better and we don't ride them for absolute performance do we? But does anyone have any real hard data on different pipes? maybe Jensen and the dyno have something?

cyclon36 · Post by **cyclon36** » Wed Jul 07, 2010 11:53 am

Looking good mike. Don't mean to go off topic, but since you have a good pic from the rear of your bike, I noticed that your rear tire seems to be off to the right and not really centered under the rear fender. Mine is the same way but the parts bike I bought was centered up. I haven't taken anything apart yet to see if anything is missing or bent. Also, what size rear tire are you running? It looks a bit thin in the pic.

Back on topic: Does anybody end up reusing the lower muffler mount that stems from the frame of the bike when using an aftermarket exhaust? I'm wanting to get some dunstal reverse megaphones like these down the road and was eyeballing that part for removal to save some weight. I notice that Mike's are hanging free and the muffler is mounted to the upper mount.

cyclon36 · Post by **cyclon36** » Wed Jul 07, 2010 11:56 am

Also, in regards to the weak mount point, I notice the mounting bracket is bolted to the rear of the channel on the muffler. Do you think shortening the bracket so it mounts in the center of the channel would do any good to even out the stress on the channel? Perhaps even do a double bracket with one attachment point on either side of the channel? Not sure if that would help or make it crack twice as fast.