Phongeer Pipe

[01EliteSR]

I really like the look of the Phongeer but ahven't really heard one. Do they make a difference in sound? I'm looking to get one for sound and looks mainly but help to build on performance I'll add later. Thought i'd ask first though, what other mods do I need to add before i buy and install a Phongeer to my stock 2001 Elite SR? Jets, air cleaner, etc?

[Limp1144]

Hey friend i live in Tn not to far from you. I would not do an exhaust till you do a big bore kit. I sell all honda elite dio parts send me a im and i can get you hooked up cheap. or call me 615-243-1121 Tommy D. Peace

[Arnadanoob]

As it was said, don't go with an exhaust upgrade until a bore upgrade. The 2 stroke exhaust isn't anything like a 4 stroke muffler/can on motorcycles or cars. The pipe on a moped has a very unique function, which is to determine the point in which backpressure is formed at a particular rpm. A muffler on a 4 stroke is there to mostly muffle sound, the 2 stroke pipe sound is an inevitable byproduct of its actual function.

Regardless of all the internet misinformation, a 4 stroke muffler (anything past the exhaust valves) will improve performance as long as the backpressure is lessened (with respect to exhaust gas velocities and turbulence at lower levels). Backpressure in 4 strokes is bad, period. By replacing a 4 stroke pipe with one that offers less resistance will increase peak power potential. I dunno how people are under the impression that the exhaust system needs to create backpressure to generate torque, I guess all of them must've failed basic math and science miserably to believe that, might as well believe the world is flat too. I guess they think the clutch bears no load or something. Oh well.

In a 2 stroke setup, pipes are determined by what range (rpm wise) the engine will be operating at. 2 stroke engines have a much narrower power band so the pipe needs to be tuned for that rpm range. If it's a stock bike, noise, fuel consumption and pollution is a problem so the bike will be tuned for a lower rpm range. The pipe for this application will have a tendency to fill up with exhaust gasses and pressurize sooner so it provides backpressure sooner so that the intake charge is held in the cylinder sooner. For a race setup, the pipe will be more free flowing and will take much more effort to fill up, which means it'll likely realize full pressure at higher rpms, which means lower rpm performance is sacrificed to gain power at higher levels.

So if you arbitrarily replace your 50cc pipe with a PG Long for example, the PG long pressurizes at a much higher rpm range than your old pipe, which means more air and fuel will blow out the exhaust, your jets won't be able to provide enough fuel to keep the Air-Fuel ratio balanced, which means it'll run so lean it'll literally have no power, possibly even bog and die out eventually due to fuel starvation.

[Wheelman-111]

Greetings:

I admired Noobs many good points, but don't entirely agree. Pipes do make a difference in 4-strokes at the highest performance levels, although the exhaust system is nowhere near as it is critical as on 2-smokers. I agree that for lower output 4-strokes, those cam-operated valves ensure that the mixture stays where it belongs, whatever pipe you plug into the exhaust port. However for those that rev to stratospheric (16,000-23,000 RPM) levels with outrageous valve timing and extensive overlap, the pipe does have the same semi-"supercharging" effect if it's correctly tuned. (and kill much of its power if not...) Just like our bikes, a good pipe designer can fine-tune the graph of the torque curve significantly, although over a much narrower range than 2-strokes. Even Harleys can see a 3-5 horspower up or down from the right/wrong muffler. Furthermore, the phenomenon occurs even in unbaffled, constant diameter "drag pipes", which are tuned simply by chopping them off at the correct length.

I'd also suggest we stay away from meaningless terms like "backpressure" because it's not a static constant thing. It's tuning the frequency and timing of pressure waves. When they arrive just in time at the desired RPM, they shove a little good stuff back into the combustion chamber just before the valve (or port) closes. It's not the pressure, it's the wave pulse. Wherever I saw that little animation of a 2-stroke in action here lately, it was a great way to envision what's going on - in super-slow motion - with these little beasts. Just stare at it for 60 seconds and you'll see what I mean.

Otherwise, what Noob said.

[burnt_toast]

here's what a pg long sounds like, at idle and at speed w/ 28mm oko and open filter \\






and on a small local rally, fly by vid

http://www.youtube.com/watch?v=Ab-mq6t9sp8

[Arnadanoob]

The pressure wave found in 2 strokes are an element found in expansion chamber pipes and not all exhaust pipes are of that design. The PG Long is not tuned that way, the internal dimensions correspond to a specific internal volume which determines the rpm point in which the pipe is pressurized and starts to develop power. In comparison a PG Short pressurizes sooner and requires less total gas volume to pressurize. The PG Long has a larger internal volume so it can handle much more gas before it reaches its power zone. This is why the PG Long is a higher displacement pipe than the PG Short, in effect the PG Short has better midrange while the Long has a better top end range. Pipes of this design are much more sturdy and will generally be better for longevity.

The expansion chamber pipe design found here is based off of what Wheelman is saying.


These pipes are computer designed and mathematically determined for a specific shape tuned for a specific displacement engine. The idea behind this design is to provide power by using the reflected pulse generated by the exhaust gases hitting the convergent cone which helps to push some of the fresh intake charge that got blown out the exhaust port back into the cylinder. This gives the engine its powerful spikey nature and in general it's more efficient, however it becomes very loud and it won't last very long due to its design. The chamber pipe easily gets clogged with carbon, the stinger portion also tends to get caked on quite quickly, the pipe is often seeing higher internal pressure and since most of these pipes are made out of thin metal, the heat cycling takes its toll after a while. This is why these pipes are usually better for race only applications. In some pipes there's a spring loaded relief valve system which allows excess pressure to temporarily bleed out to prevent catastrophic failure.