Aftermarket Exhaust (COLLECTOR PIPE)

Right about where I am at..... Yesterday, I returned my 2 brothers CF/Black series. After more research..... I decided to go with metal Stainless, aluminum or titanium. I just couldn't justify spending that much coin on Carbon Fiber when it is subject to yellowing or breaking down. CF is beautiful. But for top dollar and a daily driver?? I just don't know about that. I think I will go with metal, that is less prone to breakdown and can be painted black if preferred. Clearly the metal pipes sound just fine and plenty loud.

Right now I am focusing on the collector under the seat. What is the better collector pipe the "Y" (the somewhat Two Brothers, Scorpion, Devil*), "T" (Leo Vince*)or the "Collector Can" (Mivv*)? Any thoughts? Or is there just too many variables? Three of these units come with a de-cat pipe* even though I have an S2. Many time it has been expressed the Y is the preferred above all because it creates more of a even flow.

In terms of exhaust. In theory or in general.

What would a "collector can" do for your exhaust on these bikes instead of the more frequent Y pipe or T pipe??? Create back pressure?

Some input would be very appreciated.

- I have noticed the majority of these exhausts systems with different collectors have yielded very similar results on dyno reads on the net. I am sure there all different somewhere within the rev range from one another.

Well looks like we're going solo on this adventure. You know what they say, "ride your own ride." have to do this locally.

Haha if I had the right equipment I'd make me 3 foot piece of pipe cut 1' sections and cut two at a 45 degree weld those in a v then cut the bottom of the v off and weld the other pipe to it y pipe made ??

It's hard to really give you details on this, I'm no expert but here's my best guesses.

The Y pipe vs T pipe makes no difference, it's about whether or not they can evenly distribute the exhaust. Either shape can distribute it evenly and either shape can put too much to one can. The only downside to putting too much to one can vs the other is that it will be hotter and it may discolor on the tip if you don't clean it. You'll notice that the tip of one gets darker much more than the other, very easy to notice in the cold weather. You've undoubtedly seen this on some cars with dual exhaust; mine does it, but no pics because it's in pieces.

I could be entirely off base here, but I don't think back pressure is something to worry about. Think of an exhaust system as breathing, you have inflow (intake/throttle body) and outflow (exhaust system). An aftermarket exhaust is usually wider with less baffles so air can escape faster, i.e. you exhaling faster. Putting on an intake will increase the amount you can breathe in. The air is what allows the engine to ignite the gas, but then it needs to exhale that gas so that it can get fresh air and keep breathing. The more air you can circulate through the system the more power you can get. Breathing in or out too fast and not in sync is what leads to hyperventilating when running. So if you just put on an exhaust, your bike will breathe out faster than it breathes in also known as running lean. If your exhaust is creating back pressure it is essentially preventing the flow of air to exist the system faster than it is bringing air into the system, which would in theory help prevent it from running lean. You can get a PC3 to fix that or just run lean, it won't be lean enough to hurt anything.

Those are my best uneducated guesses. :/ Good luck!

I think you may have the wrong idea about where a collector can is used based upon the comment of it being at the muffler end of the spectrum under the seat. A collector can is nearer the engines exhaust port and is typically not a performance orientated part as its just a dump into a volume and it dirties the flow creating turbulence before it exits. They are often times cheap to make a take less physical space than a set of headers with collector pipes having 4 - into - 1 (for example). I'm not going into detail on that but think of an ideal system. In the ideal system the headers collectors combine in the firing order of the engine to keep the flow continuous. With each combustion cycle a volume of gas is added to the collector in a sequential order so as to keep the velocity continuous out of the collector while headed towards the muffler.

A Y pipe vs T into muffler, well it seems pretty slim that T will have good flow as it will create turbulence and reflections which will be harder to cancel noise wise where as continuous flow is more likely to produce a cleaner sound. Just my 2 cents on the topic.

Gelvatron said:

Haha if I had the right equipment I'd make me 3 foot piece of pipe cut 1' sections and cut two at a 45 degree weld those in a v then cut the bottom of the v off and weld the other pipe to it y pipe made ??

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Absolutely! I would totally be doing this if i had the right Equipment.

You ever notice when you go to a exhaust shop, there typically very accommodating as to what you need? Oh well.

FinalImpact said:

I think you may have the wrong idea about where a collector can is used based upon the comment of it being at the muffler end of the spectrum under the seat. A collector can is nearer the engines exhaust port and is typically not a performance orientated part as its just a dump into a volume and it dirties the flow creating turbulence before it exits. They are often times cheap to make a take less physical space than a set of headers with collector pipes having 4 - into - 1 (for example). I'm not going into detail on that but think of an ideal system. In the ideal system the headers collectors combine in the firing order of the engine to keep the flow continuous. With each combustion cycle a volume of gas is added to the collector in a sequential order so as to keep the velocity continuous out of the collector while headed towards the muffler.

A Y pipe vs T into muffler, well it seems pretty slim that T will have good flow as it will create turbulence and reflections which will be harder to cancel noise wise where as continuous flow is more likely to produce a cleaner sound. Just my 2 cents on the topic.

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Perhaps, I am using the wrong terminology. Thanks for the follow up.:thumbup: If you get the opportunity look at the attachment below. It is a diagram of a Mivv exhaust. In it you will notice the silencers merge in to a collector can or chamber, under the seat (diagram itemization 20). Do you have any idea the functionality in the exhaust for this chamber?


http://www.mivv.it/risorse/8/187/340/UY015_SUONO_SCHEMATIC.pdf
Thanks

Alright, think of that canister as kinda like a collector. It collects a little of the exhaust to use it for back pressure. A exhaust systems has to have at least some back pressure. If you don't have it, you will over heat your exhaust valves, and burn them out. It uses that cooler exhaust gas in the back pressure to keep the valves cool.
The "Y" pipe will be far better than the "T" pipe. The availability of the exhaust to exit easier and faster in the "Y" is much more so than in the "T". "Path of least resistance" The key phrase you are looking for is called "volumetric Efficiency" - How well a engine can inhale and exhale. Hope this helps

massaudio said:

Alright, think of that canister as kinda like a collector. It collects a little of the exhaust to use it for back pressure. A exhaust systems has to have at least some back pressure. If you don't have it, you will over heat your exhaust valves, and burn them out. It uses that cooler exhaust gas in the back pressure to keep the valves cool.
The "Y" pipe will be far better than the "T" pipe. The availability of the exhaust to exit easier and faster in the "Y" is much more so than in the "T". "Path of least resistance" The key phrase you are looking for is called "volumetric Efficiency" - How well a engine can inhale and exhale. Hope this helps

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What draws you to this conclusion and where is some form of proof on this? And how is that so many engines with open headers/no collectors run fine?? Granted they are not for daily street use as they are too load but, even WWII planes had 6" stacks and didn't melt valves so. . . Just sayin. . .

I have a degree in automotive engineering. How the valves are designed for each engine makes a HUGE difference !! The valves in the engines of a WWII plane where designed and machined completely differently than the valves we use now. They still ran lead in the fuel, and there for where mostly solid valves. The valves we use today are 98% hollow with some sort of liquid or powder in them to help cool them down, and we don't use lead in our fuel anymore. Hence why you cant grind down a valve of today's engines, like you could of the years long ago. There is a minimal back pressure required to keep the valves cool to prevent over heating them, or burning them out.The hollow valves tend to be able to cool easier, and are lighter in weight, hence the higher revs we are able to get out of our vehicles today. This also comes into play when you rebuild a engine from that long ago, that you have to sleeve the valves with a harder metal, because we don't use lead in our fuel anymore. The engines that run OPEN HEADERS, or NO COLLECTORS are actually doing damage every time they run them for any length of time at all. This is also the reason why drag cars replace valves after every single run. They have no back pressure whats so ever to help keep the valves cool at such high RPM's, so they know the valves are burnt and warped.

I hope this helps.
Just remember, and if you have a chance.....Google "Volumetric Efficiency"

I have to agree with massaudio I'm studying for my Automotive degree but that is cars I'm assuming that bikes are the same, inside the valves their is liquid sulfur you can "grind valves" but just the seats and the angle of the head not the stem also back pressure is a must to much is harmful I'll take a pick of the reason backpressure is needed from my book in a few

In that drawing that is mivv's version of the y-or the t not a collector, as final impact said a collector is where all the pipes "collect" into 1 or just where multiple pipes "collect" together. As far as back pressure goes as long as you have to fuel to go with the extra air flow there will be no I'll effects. If you increase the air flow with out increasing the fuel then the temperatures rise, kind of like on a cutting torch if you add more oxygen the flame gets hotter, add more gas flame gets cooler.

I can't jump on the wagon on that. AFR will do more than back pressure, a lean run can kill any engine. As an engines performance goes up so does the fuel consumption to reduce detonation and keep the burn cool so valve guides don't stick and head pop off.

On a 1 - 10 scale back pressure is more of the 1 than the 10 as far cooling is concerned. In terms of back pressure it does affect chamber filling and efficiency. You change the back pressure it changes the engines filling characteristics and turning is required to maintain proper AFR.

It seems we've ran off topic.

EDIT: let us not forget: ignition and cam timing, dwell and overlap. All greater impact than back pressure but back pressure does effect the tune and IS part of the total package when dialing in performance, reliability, driveability.

not to nitpick but usually exhausts for the FZ6 have either a "Y" or an "h" shape. and the MIVVs seem to have more of the "h" shape where one pipe buds off of the other, more direct route, even though there is a "compensator"(thats how its listed on the schematic) there.

+1 that a "Y" pipe is ideal but if you look at the offset way that the main runs up under the seat you will notice the complexity of fitting a "Y" joint, which is why most AM exhaust companies use the "h" design.

SweaterDude said:

not to nitpick but usually exhausts for the FZ6 have either a "Y" or an "h" shape. and the MIVVs seem to have more of the "h" shape where one pipe buds off of the other, more direct route, even though there is a "compensator"(thats how its listed on the schematic) there.

+1 that a "Y" pipe is ideal but if you look at the offset way that the main runs up under the seat you will notice the complexity of fitting a "Y" joint, which is why most AM exhaust companies use the "h" design.

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"h" is the cost vs benefit factor. If the can directions said throw away under-seat pan, cut and weld frame area to fit custom exhaust no one would buy them so they work within the constraints of the bikes design and that's what you get => "h" and subtle "y"s.

IMO allot of the "mufflers" are designed to fit MANY applications so to think that any given "muffler" is designed for our bike is pointless. Yes, they found a way to hang and plumb hot GASES into it but that's about it in most cases. It takes engineering time and resources to make an exhaust system which works to help the engine breath and sound good.
Anyway - I personally can't bring myself to pay $700 for cans, hose clamps and 24" of stainless when the materials are like $100 tops and the cans are universal. Its gonna take allot of this before I buy. . . but thats just me. . . Cr@p, the least they could do is make it hang on the OEM rubber insulated hanger that's on the bike.

FinalImpact said:

I can't jump on the wagon on that. AFR will do more than back pressure, a lean run can kill any engine. As an engines performance goes up so does the fuel consumption to reduce detonation and keep the burn cool so valve guides don't stick and head pop off.

On a 1 - 10 scale back pressure is more of the 1 than the 10 as far cooling is concerned. In terms of back pressure it does affect chamber filling and efficiency. You change the back pressure it changes the engines filling characteristics and turning is required to maintain proper AFR.

It seems we've ran off topic.

EDIT: let us not forget: ignition and cam timing, dwell and overlap. All greater impact than back pressure but back pressure does effect the tune and IS part of the total package when dialing in performance, reliability, driveability.

Click to expand...

I completely agree. I thought he was just asking about back pressure it's self.