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Has anyone cut the center section out of the factory collector? I did this recently to free up the obvious restriction. The tone of the exhaust was lowered and not as sharp. I will get used to it! By doing this are there any drawbacks such as exhaust pulses interfering with opposite cylinder, or less scavenging?
 

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I did mine a few months ago but with a twist on what some others have done. Of course I took no photos but I cut that centre part out but used a section of 3" stainless pipe (donated from work) and chopped that up.

Instead of fitting it so that it divided the exhaust from vertical and horizontal cylinders so that it could go to both mufflers, I set is so that it more or less guided the exhaust towards just one but still left a gap to work as a bit of a balance to the other.

Hard to say if there was a lot of difference in sound or power as I also went back to the standard early (small diameter) mufflers and took the ends off and fitted db killers. They open the ends up a bit but don't let as much noise out - slightly louder than standard but quieter than the alloy Ducati Performance slip-ons. Weird now that is smells a bit rich at idle.
 

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Did mine a year or so back? I wouldnt advise cutting the lot out? Wont flow that well for a start, the two pipes would be blowing against each other? Would improve low-end back pressure but high revs it would choke itself?



My take on things - a quartered stainless tube in the middle to divert the gases down the relevent tubes & two plates made up for either side

Four holes drilled in the plates so you can tack the middle star to stop any possible breakages later - hold the middle star together using a jubilee clip so you can edge-weld it together...

Plasma-cutter the middle section out, then TIG weld both plates and the liddle star in... (not my work - have an Uncle in the trade! I cut the tube & plates tho. :D)

Finito -




Sorted! Much more eager to rev...



- shows the extra flow gained by the new middle star & plates. :cool:
 

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I like it! Mind if I borrow it ? You could make kits up and sell them to those of us without the required tools. It has to help, as this is the major restriction in the stock setup.
 

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I like it! Mind if I borrow it ? You could make kits up and sell them to those of us without the required tools. It has to help, as this is the major restriction in the stock setup.
No prob! The middle is over-restricted to help the bike pass noise tests etc, big twins need to breathe... ;)
 

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No prob! The middle is over-restricted to help the bike pass noise tests etc, big twins need to breathe... ;)
So ideally... We'd have a before and after dyno to show some improvement by removal of this obvious restriction that we've all been looking at for years, since most of us haven't sprung for a spaghetti header. The other mod would be to increase cornering clearance, since the header is the first thing to touch (ask how I know! exciting!). I'd love to pull off my header and send it to you for those 2 changes, well executed by a pro welder that cares about his work. I bet I'm not alone.
 

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not wanting to be a naysayer and I've no proof that this isnt benificial but the 888 stradas use the same pipe diameter and cross section and produce around 90RWHP, which would be a lovely figure for a 900ss so not certain this is as restrictive as it looks.
 

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not wanting to be a naysayer and I've no proof that this isnt benificial but the 888 stradas use the same pipe diameter and cross section and produce around 90RWHP, which would be a lovely figure for a 900ss so not certain this is as restrictive as it looks.
This was a known mod for the 888 exhausts & where I got the idea from? ;)

The SS & 888 engines are worlds apart - 2v head single cam carburettor engine vs. 4v head twin cam with fuel injection, a bit like comparing a tractor to a sports car... :D Needless to say they all flow a bit better with a freer-breathing collector.
 

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So ideally... We'd have a before and after dyno to show some improvement by removal of this obvious restriction that we've all been looking at for years, since most of us haven't sprung for a spaghetti header. The other mod would be to increase cornering clearance, since the header is the first thing to touch (ask how I know! exciting!). I'd love to pull off my header and send it to you for those 2 changes, well executed by a pro welder that cares about his work. I bet I'm not alone.

Good shout. I have a spare set of SS headers so could do an exchange deal, swapping as we go? There is however a large amount of marking, cutting & welding to be done in the mod itself - & I am over the Pond in the UK. :(

I did make templates of the plates (they are a very peculiar shape? The top one is different again from the bottom one??!) so could relatively easily replicate the work done? The spag.systems are still available to buy - but would arguably make little or no improvement over this mod to a tuned SS?
 

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I have been thinking of this mod since I bought my SS. Good to see great minds think alike ! An alternate method I was considering would be to cut the X section out and replace it with a section of tube to complete the connection of one cylinder to each pipe, but Siamese the two pipes together where the X pipe was. This setup has been a proven power improvement on cars with dual exhaust. I think it would work as well in this application. Your method may be easier though. Thanks for sharing.
 

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Has anyone cut this out and left the two pipes separated? Does having a cross-pipe make that big of a performance difference even if both headers are the same length? I am going to do this or make my own spaghetti exhaust as soon as I get my SS.
 

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This was a known mod for the 888 exhausts & where I got the idea from? ;)

The SS & 888 engines are worlds apart - 2v head single cam carburettor engine vs. 4v head twin cam with fuel injection, a bit like comparing a tractor to a sports car... :D Needless to say they all flow a bit better with a freer-breathing collector.
No shit re the difference (owning both I never new) that explains why a 900ss is usually around 74odd hp and a 888(strada) around 90hp on essentially the same exhaust configuration .
Ps Some independant testing indicates it doesnt really add anything when a similar (albieht larger diameter) duc 888sp exhaust which has this cruxific method is compared to a Duc Perf exhaust using a more tubed cross section (dyno reports here BikeBoy.org - 888 With ST4 Exhaust Systems – Std and Ducati Performance ) though this is on a 4v 888 which maybe didnt need the extra flow :?
 

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No shit re the difference (owning both I never new) that explains why a 900ss is usually around 74odd hp and a 888(strada) around 90hp on essentially the same exhaust configuration .
Ps Some independant testing indicates it doesnt really add anything when a similar (albieht larger diameter) duc 888sp exhaust which has this cruxific method is compared to a Duc Perf exhaust using a more tubed cross section (dyno reports here BikeBoy.org - 888 With ST4 Exhaust Systems – Std and Ducati Performance ) though this is on a 4v 888 which maybe didnt need the extra flow :?

I was merely pointing out the 888 engine is as different as chalk & cheese to the SS - a Pani with the same exhaust would of course kick out a LOT more than either of them? Doesnt prove anything...

The SS engine is choked as standard via the airbox lid & snorkels, also by the exhaust collector. Look at how many people chop the airbox lid down for the power (& noise:D) benefits? The collector mod is no different, just a little more faff. :)
 

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I did the same thing with my Monster pipes (same engine/exhaust);



There was a guy on German ebay offering the service whose pictures I found helpful when doing the mod;



I don't know how well it runs yet as I'm still building it but it definitely opens the exhaust up which can't be a bad thing...
 

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It may not make all that much difference,but I will feel faster !
 

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I must say that before i see any dyno graphs from a jettet but otherwise stock compared with the same bike and jetting and this mod only, I will not believe that this mod will have any positive effekt at all. At best it will not make a difference.
 

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I must say that before i see any dyno graphs from a jettet but otherwise stock compared with the same bike and jetting and this mod only, I will not believe that this mod will have any positive effekt at all. At best it will not make a difference.
I had my header modded to a set of drawing Ducati Salt Lake used to have on their web site. Similar to what's being discussed here. I'd agree with your assessment.
 

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I would suggest cleaning up the welds in the standard system might yield results. I have some spare chopped headers that have quite nice welds where they meet the heads. The ones on the bike reduced the diameter by about 3mm before I took the grinder to them. It looks to me that after the split the total cross sectional areas of the pipes add up to about the same as the header pipe. I would reckon this is quite important. Google 'area rule' and 'aerodynamics' and you will get the idea.
 
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