gl_s_r wrote:If it helps I found this response a good while ago about it all, I found it funny and informative:
> > The restrictor in the standard headers is there to
> > assist the pulsing which
> > helps to scoure the front cylinder and to create a
> > turbulence vacuum thus
> > accelerating the gas speed at that point above certain
> > revs. If this is
> > removed the left hand exhaust can will discharge a
> > greater proportion of the
> > gas emmisions.as did the first Akropovic and Two
> > Brothers full exhausts did,
> > until they were modified, to the detriment of the
> > engine performance. Later
> > full systems were designed to overcome this effect by
> > changes in their
> > length, merge angles, tapers and taper length.
> > Honda, Moriwaki, Akrapovic and others could have
> > saved themselves
> > millions in R&D if they had only listened to some AU
> > guy and cut away the
> > "excess" to improve power output !!!!
I could respond by saying "What makes this websites opinions any different to another websites opinions" but I wont.
It could be said that if Honda got it so right why do you need to grind the welds out of the headers.
So do Moriwaki and Akrapovic have restrictions in the LH pipe?
AMCQ46 wrote:I think we need a full range of exhaust systems and headers represented at the next Dyno day.
That would be interesting. Random idea would be to make a little restriction you could pop in there for a run. I guess even a DB killer in one pipe would do the same.
NZSpokes: no problem with dragging sidestand. Std pegs are dragging sooner, and as it is just on the edge of the rear tyre, I don´t want to increase lean angle by changing them.
Not resctricted, but as you say, these pipes are completely different. Oem pipes are more 2-1, these are 2-2 with one joint point.
That link is not working, but I have seen it before.
I have an idea, why don't you dyno your bike as it is now, then remove the restrictor and dyno it again. If you find a significant gain in bhp right across the board then all of us with standard headers can do the same
agentpineapple wrote:does that mean both my akra full system and two brothers full system are pants.........
I wonder if lloydie will buy them from me......
When you read it through it says the "first systems" and they changed it later... but in this instance I think you should offload them to Lloyide and rather cheaply as they obviously don't work
sirch345 wrote:
NZSpokes wrote:
sirch345 wrote:No don't remove the restriction in the righthand header pipe,
That link is not working, but I have seen it before.
I have an idea, why don't you dyno your bike as it is now, then remove the restrictor and dyno it again. If you find a significant gain in bhp right across the board then all of us with standard headers can do the same
Chris.
A simple but fantastic idea Chris
Why ask... sometime you just go to do it and find out?
gl_s_r wrote:If it helps I found this response a good while ago about it all, I found it funny and informative:
> > The restrictor in the standard headers is there to
> > assist the pulsing which
> > helps to scoure the front cylinder and to create a
> > turbulence vacuum thus
> > accelerating the gas speed at that point above certain
> > revs. If this is
> > removed the left hand exhaust can will discharge a
> > greater proportion of the
> > gas emmisions.as did the first Akropovic and Two
> > Brothers full exhausts did,
> > until they were modified, to the detriment of the
> > engine performance. Later
> > full systems were designed to overcome this effect by
> > changes in their
> > length, merge angles, tapers and taper length.
> > Honda, Moriwaki, Akrapovic and others could have
> > saved themselves
> > millions in R&D if they had only listened to some AU
> > guy and cut away the
> > "excess" to improve power output !!!!
I could respond by saying "What makes this websites opinions any different to another websites opinions" but I wont.
It could be said that if Honda got it so right why do you need to grind the welds out of the headers.
So do Moriwaki and Akrapovic have restrictions in the LH pipe?
That link is not working, but I have seen it before.
I have an idea, why don't you dyno your bike as it is now, then remove the restrictor and dyno it again. If you find a significant gain in bhp right across the board then all of us with standard headers can do the same
Chris.
Dyno runs here cost more than drugs.
I was wondering if there was a reason to why this was restriction was in place. A blanket dont touch it without reason does not help much.
But I will crawl back into my hole like a good little new member.
It could be said that if Honda got it so right why do you need to grind the welds out of the headers.
You don't need to. All exhaust systems are a tuned length. It don't mean one can't experiment though. Bigger is not always better, don't forget the flow rate.
Just to add a little info gathered back in the dark ages....
Back in early '98 Dan Kyle did a back to back dyno run with the only change between the two was the first had the "restriction" in place and the second had the restriction removed.
Same bike, same dyno, same day and the bike made more power with the "restriction" in place.
If you want to wade through a ton of old BBS style info it is in yjr old "Sport-twins" archive.
Me personally, as I have stated before, I think it is there to trick the system into thinking it is variable length due to the flow path changing as the internal pressures rise.
Loud pipes don't save lives, knowing how to ride your bike will save your life.
As for grinding the welds (if you mean at the mounting collars) the best way I can put it (or have put it) is that the stock system is a good design built to a price point.
So yes there can be some improvement by cleaning things up a bit but major changes tend to make less power than stock all other things being the same.
Loud pipes don't save lives, knowing how to ride your bike will save your life.
8541Hawk wrote:Just to add a little info gathered back in the dark ages....
Back in early '98 Dan Kyle did a back to back dyno run with the only change between the two was the first had the "restriction" in place and the second had the restriction removed.
Same bike, same dyno, same day and the bike made more power with the "restriction" in place.
If you want to wade through a ton of old BBS style info it is in yjr old "Sport-twins" archive.
Me personally, as I have stated before, I think it is there to trick the system into thinking it is variable length due to the flow path changing as the internal pressures rise.
Thanks man. Nice response.
Looking at it the other day, the rear cyl pipework is not that flash. Did make me wonder how it would go as 2 separate systems.
