I have a dyno lined up and my exhaust guy is ready with some 41mm mild steel. Now i just need to get to the local engineer and have him cut up some exhaust flanges and rings to weld onto the headers and ill be set to test. Thinking if i want a stylised/finned design or just smooth flanges.... I might get a small section of 2 or 2.25 inch and make a dodgy expansion chamber to try out too, for the effort to build it itll give an answer to the theory but for a split system i think the cans will server the same purpose anyway.

Im thinking i wont get much variation from the lengths or expansion chamber but at approx $200 cost to build and test (including 2hrs dyno time, wont do too many different lengths) ill have piece of mind that its as good as ill get it, i wont waste a full stainless system on what could be a dud idea, ill get dyno figures for my bike, and ill have some fun along the way. Then itll prob cost another $500 or so in materials to make the final exhaust if its a viable design. Still to decide the style of cans i want, prob just get something from ebay/danmoto but for testing ill slip on the remus dp cans i have already.

The dyno operator thinks we could see a minor improvement with a correct sized split exhaust, based mainly off his experience with harleys, but im not holding any hopes of a gain. Minimal loss will do me fine. I do wonder on the sound itll make tho.... ive never heard a split system ducati.

the split systems are definitely louder  

http://new01.ugc.ducati.kontain.com/video/20110721/prod_da32f2d7-8ce2-4a6e-b4d4-4bc0a64663ff/af40f15c-7062-4864-8d6d-41fb5d5e862c.mp4

remember just a 696

been a little slow getting things done as its actually been sunny!!

i had a engineer turn me some steel flanges for the tester. if all goes well he will make the next set in stainless for me. will go see my exhaust guy tmr and press bend the tester setup leaving it oversized length, and then once back from the easter break ill be on the dyno. fingers crossed

with the ducati headers being 1.3mm wall 40mm pipe, when i use 1.8mm wall 41.3 ill actually only be going up 0.8 mm in diameter. ill check my supplier, and if i can i might go for some 1.2 or even 0.8 wall stainless.



Uploaded with ImageShack.us

I'll jump on the subscribing bandwagon.



Also, raux, I know you fabbed up the exhaust yourself, but mind if I ask where you bought your megaphones?

Quote from: Buckethead on April 03, 2012, 11:11:36 PM
I'll jump on the subscribing bandwagon.



Also, raux, I know you fabbed up the exhaust yourself, but mind if I ask where you bought your megaphones?

ebay
$100

Very nice. Will be real interesting to see the results.

TEASER WARNING!!

i have results!! i did runs with the shortened dp high mount remus cans, then went to split headers of 1000, 800, and 600 ml volume with some brand new danmoto conical cans. have logs for power, torque, and afr.

im bout to go out for dinner now, so ill start a thread later on with all the details.

quick tip for anyone looking for cheap cans/testing on a dyno. DONT USE DANMOTO CANS!! filled the whole damned dyno room with fibreglass!! covered me, the bike and the dyno in snow after only 2 runs and continued to spew more all the way till finished haha. can see there is only about 10% of the packing remaining in the cans now! on a plus side, they are damn light cans now but more than a little too loud... haha and im still itchy!!

TO BE CONTINUED........

I think the DanMoto are using the same packing as a dirt bike. loose fill, instead of wrap fill.

looking forward to seeing results Roaduser...

well since I started the thread about building an exhaust I better add to it.

Finally got a bit done. I've had the donut, some straight tube and 1.5mm stainless sheet for a while, what I havn't had is time.
anyhow, yesterday I made a start....



I dont have access to machinery anymore because I've moved on from my previous job, so I have to buy my own.
here is a cheap chinese TIG/Plasma cutter I bought..



I used it to cut out from a template made from the X-Box. I dont mind the shape of the xbox, but a couple of things I'll change, I'll tweek it as I go.
First time that I've used the plasma, so there is a few rough edges where I wasn't moving fast enough and the cardboard burnt which let the cutter go off track.



I hand bent the sheet to shape in this...



To end up with this...



So, its a start... I'll try to keep some momentum, but this will be a slow project...

I've come to the conclusion that I'm probably going to have to build the exhaust I want. 

You mind if I ask about your TIG/Plasma cutter setup?

Quote from: Buckethead on May 09, 2012, 05:30:20 PM
You mind if I ask about your TIG/Plasma cutter setup?

no,  what do you want to know?
there's heaps of em on ebay, was about $600 Aus.

First off, what sort of specs did you look for? Amperage, wattage, etc.

Secondly, I don't know if you've used the TIG portions of it yet, but how would you rate the one you bought for what you're doing? Adequate? Barely so? Any features you'd look for if you had to buy another one?

I've only done a few small TIG welds to see if it works ok...

I just wanted something to be able to do light ally and small welds. Its 200 amp so that should be ok for most things I want to do.

Also has stick welder function.

So far I rate it ok, you wouldn't expect pro quality for the $600.
There's a few on ebay that dont have the plasma cutter, I'll use the plasma a bit so I made sure the one I bought had it.

ok, so I've made a bit more progress and the design has changed a bit.

But I have a question.. I'm wondering if I should bring the exit (inside the box) around a bit more to help draw the gases through to help scavenge?
I could add a bit more to the radius that I welded on before I button it up...
I'm thinking that the exit from the X peice is not long enough....
Any guru advise?

yeah I've been a bit busy lately and haven't done a write up. one day soon... i have some new flanges made up in stainless and alloy for the final version to collect tmr and the bends should be already waiting so ill get to work on it soon.

MONSTA: i think the take home message i have gained is the theory is only a basis to start from, the proof is in the pudding and we don't really have a means to test it thoroughly enough at every step so i wouldn't stress the small stuff like the length of those pipes, also we are both quite possibly going to be running a slight loss in anyway. I think you should focus on the aesthetics of your design and making sure you don't run too much restriction in whatever baffle design your going to choose for inside that enclosure and you'll on a winner in my eyes.

as for the theory on scavenging, my understanding is that it wont make any difference changing that end part of pipe as any real scavenging effect will take place from where the two cylinders headers first meet. this will still be at the same point as oem for you as you have the original headers and joiner in your design. so with those pipes your effectively dealing with the length of tailpipe on a car when the scavenging is happening at the headers.

if those two pipes did somehow have a scavenging effect on each other it would be to no purpose as it would effectively be scavenging from itself... this is because a scavenging effect (or negative pressure) at that point would have its effects on the whole system and not just the opposite cylinder because the two cylinders pressures have already met and are both already at play.

hope that makes sense, and just be aware it is only my "un-footnoteable" understanding.