07 Nightster exhaust
#11
07-10-2007, 09:48 PM
RE: 07 Nightster exhaust
I talk to my buddies while next to me they at a light,aren't too bad at an idle but once you start moving you can hear them plenty.
You can set off car alarms while putting through a parking lot....get in a parking garage and you can set 5 off at once. My buddy has cycle shack pipes they are similar.
You can set off car alarms while putting through a parking lot....get in a parking garage and you can set 5 off at once. My buddy has cycle shack pipes they are similar.
#12
07-10-2007, 09:49 PM
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#13
07-11-2007, 07:37 AM
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#14
07-11-2007, 06:48 PM
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#15
07-11-2007, 09:24 PM
RE: 07 Nightster exhaust
From the factory, what is the black bar, that the exhaust mounts to, underneath the exhaust?? it has two ports in it...looks like some type of bypass pipe for the exhaust, and acts as a hanger for it..what the deal with that?? Cross-flow pipe or somethin?? Shorts-shots or the Shorties like i have 
#17
07-12-2007, 11:20 PM
#20
07-14-2007, 05:22 PM
RE: 07 Nightster exhaust
ORIGINAL: Nyter
Ok..found that out the other night, when i installed my pipes..Whats the purpose for the crossover pipe?
Ok..found that out the other night, when i installed my pipes..Whats the purpose for the crossover pipe?
But i did find this on a mustang forum
LINK
NOW - A couple of people ask about the Cross Over on a Motorcycle - They usually only have 2 Cylinders.
It is actually a little more technical but I’ll try to keep it simple.
In the case of 4 stroke motorcycle engines, the reason for a cross over is this...
After a cylindar fires and the piston cycles “up” - exhausts gas vents through the Exhaust valves, along with the remainder of the “explosion”, exiting the cylinder into the exhaust system.
This explosion creates 2 pulse waves… a Sonic Pulse - and a Thermal Pulse.
When the faster Sonic Pulse leaves the exhaust it has created a vacuum in the pipe behind it, which air pressure will enter the pipe to fill the vacuum. This air will collide with the Thermal Pulse and cause it to reverse. The timing of this event causes exhausted gases to be returned to the cylinder while the exhaust valve is still open therein not allowing all the spent gas to escape and also polluting the environment for your next stroke cycle with fresh air/fuel mix.
This “Event” is call Reversion and seriously degrades performance and lifetime of valves and cylinder heads.
The Cylinders fire opposite of each other – or nearly so on a Harley. So when One side is firing, the other side is idle. Having the cross over pipe allows the pulses to dissipate back and forth between the tubes instead of - or before exiting the exhaust and therein greatly diminishing the effects of reversion and so improve performance and engine life.
Yes - you see a lot of bikes with duels and no cross over. These are usually "Tuned Pipes".. meaning their length and size are tuned to work with the S/T Pulse in such a way that reversion can not return to the engine before the exhaust cycle has ended.
It is actually a little more technical but I’ll try to keep it simple.
In the case of 4 stroke motorcycle engines, the reason for a cross over is this...
After a cylindar fires and the piston cycles “up” - exhausts gas vents through the Exhaust valves, along with the remainder of the “explosion”, exiting the cylinder into the exhaust system.
This explosion creates 2 pulse waves… a Sonic Pulse - and a Thermal Pulse.
When the faster Sonic Pulse leaves the exhaust it has created a vacuum in the pipe behind it, which air pressure will enter the pipe to fill the vacuum. This air will collide with the Thermal Pulse and cause it to reverse. The timing of this event causes exhausted gases to be returned to the cylinder while the exhaust valve is still open therein not allowing all the spent gas to escape and also polluting the environment for your next stroke cycle with fresh air/fuel mix.
This “Event” is call Reversion and seriously degrades performance and lifetime of valves and cylinder heads.
The Cylinders fire opposite of each other – or nearly so on a Harley. So when One side is firing, the other side is idle. Having the cross over pipe allows the pulses to dissipate back and forth between the tubes instead of - or before exiting the exhaust and therein greatly diminishing the effects of reversion and so improve performance and engine life.
Yes - you see a lot of bikes with duels and no cross over. These are usually "Tuned Pipes".. meaning their length and size are tuned to work with the S/T Pulse in such a way that reversion can not return to the engine before the exhaust cycle has ended.