Ducati 1000 DS custom build

[buzzer]

When i bought the bike it had a QD system on it… while I liked the concept, it was too big and heavy so I sold it on and decided to make an underslung exhaust of my own design. I wanted smaller and much lighter. I started with a mock-up of builders foam to get the shape and angles, and then moddled this in 3D. I did do a basic model on my iPad, but then found I had to pay to output it to a file! really frustrating! so I got my mate to do it and then had all the individual parts laser cut.

The baffle plates have staggered holes, which should quieten it down somewhat, but if not, I have a backup plan! Who knows if this will kill any performance? if I lose a few BHP so be it… but you never know!

here is a 1 min video of the process

https://www.youtube.com/watch?v=RgssU93IbPM

[Darren69]

Shorter exhaust tend to rob torque esp. from a v twin. Which is why Termi full systems have all those spaghetti manifolds to maintain and improve gas flow using negative pressure created by the other cylinder. And it works 10% more torque/power on an S4 with nothing more than the exhaust. You can feel the torque come onto the pipe in a similar way to 2 stroke expansion chambers.

[buzzer]

Originally Posted by Darren69

Shorter exhaust tend to rob torque esp. from a v twin. Which is why Termi full systems have all those spaghetti manifolds to maintain and improve gas flow using negative pressure created by the other cylinder. And it works 10% more torque/power on an S4 with nothing more than the exhaust. You can feel the torque come onto the pipe in a similar way to 2 stroke expansion chambers.

spot on... Lets see how it goes... i do expect to lose some performance... but these days its faster anyway than i can think!


Apart from a polish the exhaust is welded up and finished. I didn’t want to have distortion and burn through when attaching the baffles, so for these I used TIG braze which worked quite well.

The slip joints are held together with springs and to hold these I needed to make some spring hoops. These are actual quite difficult to make to get the bend just right and to a consistent shape. I made a little jig to make these.

[utopia]

While I admire all of your work and I do appreciate that the exhaust is not being built with performance efficiency at the top of the list, I must say that I've never been a fan of this type of exhaust.
On top of Darren's comments about long systems working better on these engines, the flow characteristics from having a short header leading to a weird shaped box containing weird shaped baffles and an exit through stubby tailpipes, none of which align with the natural flow direction must be awful.
However as usual, it is all being built faultlessly and I'll repeat .. I do understand that performance is not the major requirement here.
It still makes me whince a bit though.

[Mr Gazza]

It's a neat piece of work for sure. I've had a few goes at designing one of those Q-D Style boxes myself, but it's hard to get the length in the box without it becoming very bulky and defeating the object of minimalizing the visual impact of silencers. They are loud and inefficient too, so I've just gone down the route of doing away with exhausts altogether.

[900Rebuilder]

Originally Posted by Darren69

Shorter exhaust tend to rob torque esp. from a v twin. Which is why Termi full systems have all those spaghetti manifolds to maintain and improve gas flow using negative pressure created by the other cylinder. And it works 10% more torque/power on an S4 with nothing more than the exhaust. You can feel the torque come onto the pipe in a similar way to 2 stroke expansion chambers.

I've opted for Silmotor 45mm headers on my 900 as I am hoping for the same or similar results to what you have described coupled with 2/3 length open cans, open top airbox (mwr) and some flatslides.

Not a question on the build quality or skills on show here but those style exhausts are not for me including those which RoadRacing sold back in the day.

Interesting build

[buzzer]

Originally Posted by utopia

While I admire all of your work and I do appreciate that the exhaust is not being built with performance efficiency at the top of the list, I must say that I've never been a fan of this type of exhaust.
On top of Darren's comments about long systems working better on these engines, the flow characteristics from having a short header leading to a weird shaped box containing weird shaped baffles and an exit through stubby tailpipes, none of which align with the natural flow direction must be awful.
However as usual, it is all being built faultlessly and I'll repeat .. I do understand that performance is not the major requirement here.
It still makes me whince a bit though.

i cant disagree I just wanted this build to be different... However... secretly I have welded a few spare lugs so if I later decide on either twin, single side, or even under seat exhaust the option is there...

[Mark64]

Originally Posted by buzzer

iso if I later decide on either twin, single side, or even under seat exhaust the option is there...

Do all three , if you don't, you daren't

[Darren69]

Those Roadracing exhausts and those others like that, QD box are morr about style than performance. Just remember that when the Monster with ugly exhausts beats you from the lights and destroys your standing quarter time. How cool will you be then?

[utopia]

Originally Posted by buzzer

i cant disagree I just wanted this build to be different... However... secretly I have welded a few spare lugs so if I later decide on either twin, single side, or even under seat exhaust the option is there...

In that case I'm with you, 100%....

[buzzer]

here is everything to go to be powder coated. The swinging arm will be just blasted though as I will be polishing that. In some ways it was a shame to strip the wheels as they were perfect, but black, and I want silver. The powder coater insists they are stripped of the powder coat before I send them, as its so difficult for him to blast it off… in the past I have used industrial paint stripper but its expensive, and a terrible job to do. This time I took them to a local car wheel refurbishes and they put then in their stripping tank for a couple of hours.. they came out fantastic, the pain literally fell of! I left the disks on and they came out without any paint on as well. I will be taking my engine cases in next!

last post for a month while we go and get some sun!

[buzzer]

back from holiday, and the first job was a frame repair on a Triumph... I don't do work for other people these days, but one of my best mates asked me if I could repair this Triumph frame for him. How the hell do people think using rebar and welding like that is acceptable?

all done now though and once its powder coated it will be like new.

[Mark64]

That's not welding, that is the poor effort of a steel butcher, probably trained by Dewhursts

[Kato]

Maybe this should go on that Triumph

[Bitza]

Just to go back to the exhaust (sorry I've been distracted by house renovation), when I designed my silencers (?!) I tried out a principle that I had read about in some trade literature possibly for Fox exhausts. Anyway the basic idea was that you can achieve some degree of silencing by having the exhaust gases travel through a suddenly increased cross section prior to exiting. So in my case I modeled the silencers on reverse cone megas, with the first cone being a muffler, and the reverse cone being a void of increased section prior to exiting a hole the same diameter as the inner muffler tube. There are no baffle plates or any form labyrinth system, just straight through. The result is questionable but they seem to me to be reasonably quiet at low revs, coming on song at about 4 to 5k when they might be quite loud.
Just thought this might be of interest to others designing their own exhaust.