The Ducati Ebay Special

Re: The Ducati Demon

DesmoDog said:
99.9% of all vehicles on the street today have unequal length exhaust runners. For what you are doing it won't make a bit of difference.

Perfect, I'll take that as i can have at it. I cut the exhaust that was on it apart, and saved the receivers going into the head just in case. I also spent 2 hours finishing that windscreen with my pencil blaster. Looks sooo good but not worth the 4 hours i have into it total. I am also going to blast a whole slew of other parts where the finish has seen better days.
 
Re: The Ducati Demon

Cones came today. Throught the creative use of duct tape and zip ties I think I came up with a design in that clears everything and won't burn the hell out of me. I not sure I ordered enough bends, gonna be close!
 
Re: The Ducati Demon

jag767 said:
Cones came today. Throught the creative use of duct tape and zip ties I think I came up with a design in that clears everything and won't burn the hell out of me. I not sure I ordered enough bends, gonna be close!
We need pics!



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Re: The Ducati Demon

Heres is the sandblasted screen and muffler placement. It will be adjusted a little
 

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Re: The Ducati Demon

make the exhaust fit how you want it to. with the engine configuration, it's pretty hard to get everything equal. ducati would increase the diameter of the longer pipe at the same length as the shorter - ie, 999 or mhe. and the elephants or grand canyons were just way different.

but i doubt you'd really see a difference. given the difference in firing order, i'd think they'd need to be different lengths to make it from a scavenging sense anyway.

whereas equal length is more about the tuned length thing.

as a really gross generalisation, the more you "tune" an inlet or exhaust length the higher the peak torque becomes and the range over which it peaks narrows. shorter tends to give you less peak, but wider range. broadly speaking.
 
Re: The Ducati Demon

Google "ducati spaghetti exhaust". They were the shit on the air cooled bikes and the 851 / 888 line.

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Re: The Ducati Demon

Well, got the exhaust started, at least as far as I can go at the moment. The tubing gets here Friday, and being I didn't know I was going to be making the headers when I ordered it, I really hope I have enough. My goal is to have it done for Saturday.
 
Re: The Ducati Demon

So next on my list after the exhaust is scrutinizing that swingarm swap. I think the guy who did it fucked it up a little, it looks like he used a pivot bolt that is way too big, and didn't put a spacer so it cant be tightened. Also, there needs to be a spacer on each side of the case, which I don't think there is. In theory I think it is free to slide from side to side. Once my stands come I will take off the rear wheel to confirm, jacking up this bike is impossible. While on this topic, i've never dealt with a single sided swingarm, or a monoshock. Would anyone want to give me a crash course on how the monoshock works? I notice there is a rod with what looks like heavy duty heim joints, the shock, and a mount that pivots.
 
Re: The Ducati Demon

swingarm moves up, pushing pushrod and moving rocker up at front tipping rear of rocker down compressing shock, which is also being compressed from the bottom by the swingarm coming up. linkage positioning and lengths of arms gives ratio and variation thereof.
 
Re: The Ducati Demon

brad black said:
swingarm moves up, pushing pushrod and moving rocker up at front tipping rear of rocker down compressing shock, which is also being compressed from the bottom by the swingarm coming up. linkage positioning and lengths of arms gives ratio and variation thereof.

Thanks! I need to figure out exactly what the PO did, shock travel, swingarm travel, etc, and figure out if it was the right way to go.
 
Re: The Ducati Demon

Started on the exhaust, and man what a pain making that rear header. 5 different pieces to go from the exhaust port to just past the monoshock, maybe 15 inches, while the front header was extremely simple. The front pipe will be 1 piece, but due to the crazy bends and how it has to be spun into position, the rear pipe it be sleeved and bolt together. I figure 2-3 hours to have the full thing tacked up, 2 more to fully weld it, then another 7-8 to grind it all down and polish it.
 
Re: The Ducati Demon

Eagerly awaiting that masterpiece!


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The Ducati Demon

That rod with the hemi joints can be replaced with one that allows quick ride height adjustments.

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Re: The Ducati Demon

Rusnak_322 said:
That rod with the hemi joints can be replaced with one that allows quick ride height adjustments.

7e39725e64691d77c6b597b56c1a3581.jpg


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Hmm interesting. Well, I made a ton of progress, was too dark for good photos, I will take some tomorrow. The exhaust took 15 pieces of tubing, plus the welds for the cones. I only got some of them ground out, I have a lot of work to do to make it pretty yet. I also have to make the mounts for the rear of the exhaust, aND adjust it a little to make the cones line up perfectly. I figure I need another full day, then if I choose to polish it, one more day.

As far as the sound, it's a little quieter, but not anything to write home about. Once I have it secured better I'm curious how it sounds riding.
 
Re: The Ducati Demon

Equal length headers will only make a difference if you run a merge collector for scavenging.

Run separate headers into mufflers and it won't make a difference if they are unequal length.

Might even sound cool with slightly more uneven exhaust rumble, like a harley. LOL.
 
Re: The Ducati Demon

2002 is the st based frame, which had a very similar layout rear suspension linkage to the sbk. shock offset would be different because the st/m exhaust exited left and down, whereas the sbk went right and out to the side. but component wise it should be pretty similar. not sure why the rocker set up would need to be changed. the inner sleeve needs to be held tight in the frame, some st break the pivot bolt if it gets loose allegedly. from memory it's 85nm, so tight.

the s2r/s4r arm is a bolt in, wonder why they didn't use that. usually you need to narrow the cases to fit the sbk "bearing in arm" swingarm to the "bearing in case" engines, but maybe they bodged that bit. or just left the inner spacers out and narrowed the arm.
 
Re: The Ducati Demon

brad black said:
2002 is the st based frame, which had a very similar layout rear suspension linkage to the sbk. shock offset would be different because the st/m exhaust exited left and down, whereas the sbk went right and out to the side. but component wise it should be pretty similar. not sure why the rocker set up would need to be changed. the inner sleeve needs to be held tight in the frame, some st break the pivot bolt if it gets loose allegedly. from memory it's 85nm, so tight.

the s2r/s4r arm is a bolt in, wonder why they didn't use that. usually you need to narrow the cases to fit the sbk "bearing in arm" swingarm to the "bearing in case" engines, but maybe they bodged that bit. or just left the inner spacers out and narrowed the arm.

There was a bunch of welding done and it's obvious they changed out the way it mounts to the frame. Other than being super chunky, seems ok there. I need to get the rear wheel off so I can really look in, I can't tell if it's tight to the case or not, that's my primary concern. They didn't modify the swingarm from what I can tell. From where I see there pivot bolt can slide back and forth, but when I hit it with a dead blow it doesn't move. I have no idea what's holding it tight, so I think I want to take it all apart and see exactly what was done.
 
Re: The Ducati Demon

jcw said:
Equal length headers will only make a difference if you run a merge collector for scavenging.

Run separate headers into mufflers and it won't make a difference if they are unequal length.

Might even sound cool with slightly more uneven exhaust rumble, like a harley. LOL.

Lol, one pipe looks like a constricted snake, and the other is freer but longer. Has a very interesting sound at idle, it is similar to a harley actually.
 
Re: The Ducati Demon

Well I have to make some revisions but iteration 1 is done. I'm not exactly happy with it, but I should have time to make some changes tomorrow. I still have all the finish work, but being that it works just fine, i've been riding it a little. It is still a very loud bike, but it's way better that it was with no mufflers at all. I'm fin ding the more I ride it, the more I don't like newer bikes.

What I do like:
The motor kicks ass. I mean really. Great torque, excellent sound, and what's not to like in fuel injection?

What I don't like:
The ride height is insane for all 5' 6" of me. I like to flat foot a bike, and I came barely get my toes down!
The weight. I know 400 lbs is considered light, but I think it has more to do with the higher center of gravity than I am used to.
The wide tires. I feel like I am on a tank. What I loved about my 350f is how nimble and flickable it was. None of that exists here.

There's a perfectly good solution for all this, heavily modify the frame getting the motor lower to the ground a couple of inches, getting the seat height lower, and getting lighter components on there. I'm thinking maybe a set of 35mm forks, delete the swingarm in favor of a traditional style, and run dual shocks. Then I can go narrower rims and tires of the 18 inch variety. For the hp I don't see why something like a 120 out back and 100 up front wouldn't work. Also, different gas tank and seat for sure.

This would happen til the winter for sure, and will be a significant investment, but the more I think about it, the more I like the idea.
 
Re: The Ducati Demon

In other words, this:
 

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