Installed Muzzy exhaust system an PCIII

[Fergi]

Boy, that looks great and you lost a fair amount of topside weight. Where did you get it from? I really liked the left side look and I now understand more fully a 4 into 1 system. Thanks to all Roadhammer

I ordered the pipe directly from Muzzy. They also provided the map for the PCIII.

 

[Fergi]

BTW Fergi, nice looking bike, fast things usually are blurry!

Thanks Bigtime,

I'll try to do better on the pictures next time.

 

[bryguy322]

A while back i was looking at the muzzy system, but i read it had a clearance issue when corning. Just a little bit ago, I thought I read a post about Muzzy fixing that. Am I right or just cracked? I'm thinking on getting the system again, but I'm concerned about the dragging pipe. I also thought about the dw setup, but don't much care for the idea of grinding things down to make it work.

Edit: sorry, I did some more searching and found the following post. I believe that's the answer to me question.

Previous Thread

 

[exskibum]

Thanks, Bigtime. Again, I understand how a header works, I just don't understand once the exhaust gases reach the collector how it can be more efficient to route them out a single pipe than to route them out two (or more) of them....assuming that the single pipe isn't significantly larger, of course.
Don't mean to hijack the thread, Fergi. The bike...and the new pipe...looks great. I just never understood the logic behind going to a single exhaust on the FJR.

One important part is being left out of the explanation. It isn't so much that the header is more efficient getting the exhaust gasses out, but that it is more efficient at getting more mixture into the cylinders.

Each pulse of exhaust gas from an individual exhaust down tube entering the collector exerts a negative pressure wave (vacuum) back up another down tube, and the down tube lengths are tuned so that the negative pressure wave arrives at the exhaust port of the other cylinder during what is called "overlap". Overlap occurs at the end of the exhaust stroke, and beginning of the intake stroke -- both valves are open a little bit at those times. People tend to think in terms of 4 distinct strokes with the valve operation also being equally distinct, but it ain't that way -- just look at the shape of the cams to visualize the opening and closing of those valves as a gradual to full open to gradual close.

Because of this vacuum pulse arriving at overlap through the still open exhaust valve, more air fuel mixture is sucked into the cylinder from the intake tract (earlier) through the opening intake valve. And that air fuel mixture is traveling into the cylinder at a higher speed than without the vacuum influence. So, when the exhaust valve is fully closed, the greater inertia of the air fuel mixture also stuffs more of itself into the combustion chamber at higher pressure than if the header design had not influenced the volume and speed of the mixture entering the cylinder.

More mixture crammed into the cylinder at higher pressure = more power. Which explains why you typically see lower mpg with a tuned header but more power, and why you typically need to rejet a carb or map longer pulses on the injectors to get the appropriate air fuel ratio when it's getting more air into the cylinder. The obvious corollary is that adding a header without adjusting the amount of fuel coming through the intake tract will typically result in your engine running lean.

HTH

 

[RiderCoach Lar]

I appreciate that explanation of the dynamics of a tuned header, skibum. Can you take it one step further, however, and explain why routing the exhaust gases in the collector into one single pipe is better than routing them into two (or more)?

 

[exskibum]

I appreciate that explanation of the dynamics of a tuned header, skibum. Can you take it one step further, however, and explain why routing the exhaust gases in the collector into one single pipe is better than routing them into two (or more)?

Not really. You'd need to talk to someone with fluid dynamics or gas flow engineering expertise. Where's jestal?

I believe it has to do with maximizing the influence of the other pipes on the vacuum in the influenced cylinder, however, and that may be duration of the vacuum pulse during overlap, but I don't know for sure. I do know that a true 4 into 1 (4-1) generates more horsepower at top end RPMs at the expense of a mid range flat spot (therefore, usually a racing app nowadays), while a 4 into 2 into 1 (4-2-1) won't give you the same amount of top end RPM power as the 4-1 but minimizes the mid range flat spot. 4-2-1 is typically what we're talking about for street applications nowadays, and that's what the Muzzy is (look at its collector closely). IIRC, the Kerker 4-1 on my '75 Kaw Z1 was a true 4-1, and I'm lucky I didn't grenade that engine on a couple of occasions -- since it didn't have a rev limiter as far as I know.

FWIW, I understand that you have a lot more of this mechanism at your disposal with a 4 cyl engine than a 2 cylinder.

 

[Shifter125]

For those interested in Muzzy exhausts, I found a site with great prices...58cycle.com...bought the 4-1 stainless for my '08 for $637 delivered. Their prices for carbon / titanium cans are even better vs. list.

Link

 

[northsouth]

Thanks alot Shifter 125 - You just cost me $842 for a Titanium system. I need to stay away from this site for a while.