S Exhaust with Dunstalls

I'm thinking of changing my '71 to a street tracker. I already have a set of Kim Tab mags on it, a SS tank and a Corbin. A set of S pipes should complement the look, but I'd rather use Dunstall mufflers. Peashooters are OK, but I prefer the sound of Dunstalls. Anybody done that yet? Since it will be a solo seat, I won't care about heat shields for the mufflers. I think I will need the heat shields on the exhaust pipes. Maybe have to use the clamps on both ends.

Yummy to the tummy on what I call Long Dong Dunstalls silencers/mufflers. You may have to re-think fab up your own more beefy supports as Long Dongs with all the actual muffling pipe cluster and bean can bolt device weights a good bouncing at the very ends. A super trap with enough plates not to bog also weights about as much. A plain supertrap plate with `1 3/4 hole blew out center worked for me for deep thumpy low throttle yet proper race Roar getting it on in places power sounds are desirable or not one to notice. I think I still have a pair of pipe shields for the duals on one side set up. The Long Dongs acted like power adders over peashooter in my late Combat 2-1 special. There is some top speed assist by the aim of the exhaust filling in low pressure zone but Norton got it pretty right as is. IIRC with complete muffler device installed each mega weight like 9+ lbs and about 6 gutted. They do tend to tug on the muffler clamp area more than a 6 lb and shorter peashooter.

Where do you plan to get your Dunstalls?
Jaydee

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Here's a few pictures that may help. The exhaust on the Harley is interesting, because if it's not too customized, and available, then it appears it could be mounted on the left side of a Norton with S pipes. It looks like some kind of Super Trapp to me.

Previous posts have cited significant horsepower increases for the S pipe configuration, most notably from Jim Comstock in this thread: big-bore-head-pipes-and-mufflers-t7386-45.html


Emgo and Helix sell Dunstall copies, which dimensionally are almost identical to one of the original iterations of the Dunstall "Decible" Silencer. Between the Emgo and Helix products, there appears to be a slight difference in the shape of the exhaust end of the muffler. Internally the two are probably the same. A lone Amazon reviewer claims the Helix and Emgo mufflers are made at the same factory, in Taiwan.

















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jaydee75 said:

Where do you plan to get your Dunstalls?
Jaydee

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Here's one option:

http://www.vikingexhaust.com/getPart.asp?id=57

Robert_Norton said:

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Previous posts have cited significant horsepower increases for the S pipe configuration, most notably from Jim Comstock in this thread: big-bore-head-pipes-and-mufflers-t7386-45.html

Click to expand...

In that thread Jim mentions that the motor has been hotrodded, considerably. (?).
The cam in particular.
Only a coupla ponies on a stock-ish bike, but thats worth having...

And you have to be able to check these things and adjust to suit.

Thanks Robert_Norton. That '70 Commando is what I'm looking to replicate. I have the Dunstall silencers already. Bought them in '74. They're the early ones that don't come apart. I think they're lightet that the later one's that are widely copied.

Robert_Norton said:

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Emgo and Helix sell Dunstall copies, which dimensionally are almost identical to one of the original iterations of the Dunstall "Decible" Silencer. Between the Emgo and Helix products, there appears to be a slight difference in the shape of the exhaust end of the muffler. Internally the two are probably the same. A lone Amazon reviewer claims the Helix and Emgo mufflers are made at the same factory, in Taiwan.

Click to expand...

Dunstall decibels “muffers” are still manufactured by foreign firms, and tent not to be very durable as per picture of the rear of ;




Also see;
was-paul-dunstall-mad-t403.html