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Twin Exhausts Inline Four - Why?
Posted: Fri Jun 17, 2011 9:42 am
by Bogan
Won't someone please think of the children? Why do people do this?
I understand some bikes come factory fitted with twin pipes (ZZR1200, ZX14, z1000 etc.) but if you were doing the replacement thing wouldn't you be better off with a 4 into 1 than a twin system? Is it because when people just buy cans they have to buy two?
Is this still cheaper than a full 4 into 1 system or just easier?
Wouldn't a 4 into 1 be lighter?
I understand with twins or V4s that dual pipes could be the go but an inline 4 will be better off with 4 into 1 yeah?
I don't geddit...

Re: Twin Exhausts Inline Four - Why?
Posted: Fri Jun 17, 2011 11:54 am
by chimp
depends if you want to keep the look? my z650 resto had 4/1 but i'm changing it back into 4/2..my Gpz750r was 4/2 and is 4/1.. but hey i'm a slut I just do want I want

Re: Twin Exhausts Inline Four - Why?
Posted: Fri Jun 17, 2011 2:12 pm
by MickLC
Power delivery is different between 4-2 and 4-1 so it's not just about styling and weight
http://tinyurl.com/5tlyscu
Re: Twin Exhausts Inline Four - Why?
Posted: Fri Jun 17, 2011 5:15 pm
by smithy5
Feng Shui

Re: Twin Exhausts Inline Four - Why?
Posted: Fri Jun 17, 2011 5:32 pm
by the kid
smithy5 wrote:Feng Shui

Im with you . Ommmmmmmmmmmmmm
Re: Twin Exhausts Inline Four - Why?
Posted: Fri Jun 17, 2011 6:38 pm
by Chitchats
I love the look, especially with some after market cans.
Re: Twin Exhausts Inline Four - Why?
Posted: Fri Jun 17, 2011 7:54 pm
by pittster
Bogan wrote:Won't someone please think of the children? Why do people do this?
Hahaha funny funny stuff nearly fell off chair seriously
While there are differences in 4-2 vs 4-1 most systems that have twin outlet pipes normally go 4-2-1-2 or 4-1-2
Actually most v-twins even go 2-1-2 or 2-1
From my past work and all the dyno runs we did and out of all the myths we busted only crazy harley guys go 2-2 with no balancing pipe between each pipe while this picks up a very small peak hp gain it slaughters torque down low. Also the tourer harleys with 2-1-2 would lose peak power and gain no torque over 2-1 setups.
Moral of the story as long as it goes to 1 after that point its weight and looks.
Note: The above is for most motor power applications there are exemptions i.e. drag bikes, moto gps long tuned length runners per each cylinder but these still balance at some point i think could be wrong

Re: Twin Exhausts Inline Four - Why?
Posted: Fri Jun 17, 2011 7:58 pm
by MAXUMIS
the 4 into one allows a more equal distrubuhion through all cylinders great for power with the write pipe diameters but they do go a 4 into 2 into 1 witch gives a wider power band the 4 into 2 is more of the syle of bike they still flow good (better in standed form)but need a decent cross over to conbine all the cylinders but more weight.
Re: Twin Exhausts Inline Four - Why?
Posted: Sat Jun 18, 2011 10:06 am
by Disco
Re: Twin Exhausts Inline Four - Why?
Posted: Sat Jun 18, 2011 11:04 am
by MrWasabi
Cos dual pipe two brothers exhaust on a 6 look hot. Nuff said

Re: Twin Exhausts Inline Four - Why?
Posted: Sat Jun 18, 2011 7:33 pm
by Phil
Disco wrote:Bogan wrote:
Is this still cheaper than a full 4 into 1 system or just easier?
A set of twin slip-on's is still cheaper than converting to a single as you then need a full system.....Also not all companies do full system's ie:Screaming deamon do an awesome twin slip-on for my bike but no 4-1....And I can't ride my bike to it's potential so would be wasting money chasing a few extra HP
Its more the manner in which its delivered IMHO, I will hold my little Z up as exhibit A

It aint got alot, but its delivered in a laugh-a-minute kinda way
BTW I'm not fussed, each to thier own - but I wont own a 4 cylinder bike with twin pipes

Re: Twin Exhausts Inline Four - Why?
Posted: Sat Jun 18, 2011 10:35 pm
by Strika
I like some 4 cylinder twin exhaust bikes. Like the GSXR1100, the ZZR1100, CBR1000F. I think they suit the bike. But, I don't think a twin exhause on a 2011 ZX6R would look all that cool....not even a little shortie under the bellypan.
Oh, and if nothing makes sense...it's OK, I'm wankered.....

Re: Twin Exhausts Inline Four - Why?
Posted: Sun Jun 19, 2011 9:26 am
by Daisy
Symmetry.
Re: Twin Exhausts Inline Four - Why?
Posted: Mon Jun 20, 2011 4:42 pm
by Naked Twin
I thought, well I have seen it done of v8's is to take it 4 into 1 with a correctly designed exhaust will create a vacuum in the manifold and in effect suck the exhaust fumes out from the ensuing firing cyclinder, thereafter I figure it is looks and weight.
Then again I only read and watch the shows, nfi on actually putting into practice.
Re: Twin Exhausts Inline Four - Why?
Posted: Mon Jun 20, 2011 7:20 pm
by Jonno
Some of it is to do with emission's and noise control from a manufacturing point of view.
ZX12R for example has one of the biggest single cans around and being a sports bike singles were the norm at that time..
ZZR1400 comes with 2cans as it fits with earlier model designs (symmetry) but also easier to make emissions and noise constraints.