Motoscrubs.com

Hi folks -

is there anybody out there who has compared the properties i.e. loudness and performance of a Silentium and a Conti muffler/silencer?
I have the Silentium as depicted, apparently a resonance chamber type. Not the whole length is used to create resonance chambers, maybe only half of it.

Is the Conti as offered by ducativintagestore.com any different internaly apart from the end cap? Which type might be less loud?

Kind regards

Wolf

I'm sure you will get many opinions on this personally I hate silentium silencers and would only put one on a Ducati single for the sake of the originality freaks, I have never once found a Ducati single that didn't run better once the dreaded silentium was replaced, I have always found they strangle the life out of the engine and frankly any more free flowing "silencer" will let the engine rev properly (of course a little carb tweaking will be required). As far as the noise is concerned.......well up until very recently I had ran my 350mk3 on an open reverse cone race megaphone but I lived for twenty years well away out in the countryside, I have now moved back into suburbia (god help me ) and to placate my new neighbours (before) the complaints started fitted a Dunstall decibel "silencer" which still lets the bike run properly and has cut the noise down by about20%. I only used a genuine Conti once on a 250 desmo I owned and I felt it didn't run nicely on it....and I didn't like the noise of it either A Conti is just a straight through absorbsion pipe and there are many pipes of this type available at a fraction of the cost.........just my opinion......others may, and probably will differ
Cheers,
George

George,

thanks a lot for your insights - the Dunstall decibel silencer looks interessting, also price wise

Cheers

Wolf

Aye Wolf,

Used to run a variety of cheap exhausts that the 450 MKIII disemboweled of it own accord leaving a trail of smoking remains on the carriageway.

As George says intake and exhaust restriction does not sit well with the singles. In a genuine Conti there is a gap between the perforated intake tube and the exhaust tube and the perforated tubes disrupt the exhaust gases sufficiently to take the "edge" off the exhaust note, yet retain sufficient speed on the exhaust gases so that they extract from the engine.

I used to run a cheap chrome, alloy reverse coned exhaust. Once the perforated steel tube and wadding had disintegrated, the engine, with enrichment ran more smoothly thoughout the rev range. The same was true of a pattern 'Gold Star' exhaust. An Armour pattern 'Gold Star' exhaust stifled the exhaust gases so badly that a blue and gold ring developed around the body of the exhaust and the engine refused to exceed 5,000rpm.

At present I am running the cheap pattern 'Gold Star' exhaust, inside which I have fitted a silencing element devised by Motad Exhausts for the late Royce Creasey, of FF motorcycle fame, along with Malcolm Newell, using a 450 MKIII engine. The element uses a cartridge oil filter body, in which are drilled 4 equidistant 12mm holes on the circumference of the filter. Perforated steel tube (42mm ID) that extends into the oil filter by 50mm, so that the end extends to the centre line of the 4 circumference holes. Two steel plates, of a diameter equal to the internal diameter of the exhaust body and with a central hole through which the perforated pipe can be passed and welded to. The oil filter is welded to the engine end plate and a reverse cone on the exhaust end plate that has a reduction of 25% of the exhaust pipe cross-sectional area. The 100mm of perforated steel tube between the two plates is wrapped with glass fibre motoX exhaust silencer wadding and the whole element welded into the main body of the exhaust and then finished off with Sperex VHT matt black. The 100mm length is the dimension that fitted in my old exhaust body. Greater length and hence more wadding would further quieten the exhaust note, but not impede the gas flow. So far, after nearly 7,500 miles I have found it to be successful for my needs. Plenty of mid range, no noticeable choking of the engine up to 6,500 rpm and the wadding takes the "crack" off the exhaust note, but doesn't stifle the note!

I attach the Royce Creasey sketch for information and two sketches, I think from Nigel or maybe George (apologies if this is incorrect ) of the internal baffling in a Dunstall exhaust.

Good health, Bill

Thanks a lot Bill,

especially for the drawings of the internals of the mufflers. I've done a little work in the past on my exhaust of my TT2, only an absorption damper but I think it is an improvement anyway. Let's see what the winter will bring...

All the best!

Wolf

I have run my Mark3 NC ( Mach1/ race engine tune) on a Norton Dominator cheroot ( 1960 style ) silencer for many years . Very similar in shape to the Mach 1 silentium its free flowing big bore . A bit noisy but fits with little issues using a Dommy bracket . Seemingly no limit to the revs ! but I do get some carb blowback thats most likely due to the unidentified cam with vast overlap but moderate lift.

...I've bought me the short Conti "Silencer" - and I'm quit content with it. The sound is nice, the loudness acceptable (in my opinion) and the perfomance also feels improved. The old silencer was sold. Happy!