kvnnets
Well-Known Member
- Messages
- 1,002
- Location
- Oakville, Ontario, Canada
This might be helpfull.
" Tuned Pipes - Or how the Resonance Effect is affecting Performance"
We all know that the exhaust pipe and the length of the manifold have an
effect on our engine's power output, but how exactly does it work?
First, imagine an engine with all ports, like the one below:
http://www.twf8.ws/new/tech/tip/setup/twostroke.gif
In our two-stroke engines, the intake port and the exhaust port are open at
the same time. This means that the amount of fresh mixture that can be
trapped in the combustion chamber is limited. An engine produces the more power
the more fuel/air mixture detonates.
Thus, our goal is to increase the amount of fresh mixture burnt during each cycle.
To do so, we need something that prevents the fresh mixture from leaving the
combustion chamber unburnt.
http://www.twf8.ws/new/tech/tip/setup/backpressure.gif
You see that the burnt exhaust gases form a pressure wave
which goes to the end of the pipe (or the baffle), then
reverses direction and prevents the fresh mixture from leaving
the combustion chamber. This walve is called back pressure.
So, knowing all this, how can I improve my buggy engine's performance?
What you can do to tune the exhaust system to your liking is to change the
length of the exhaust (distance from engine's exhaust port to pipe's baffle).
You can normally tune that by adjusting the length of the coupler (connecting
tube between manifold and pipe). Making it longer means that the pressure
wave takes longer to come back. The result is better performance at low revs,
that's more bottom end, acceleration. Having a shorter exhaust means that
the pressure wave is back faster, so you have the resonance effect in the high
revs. The result is additional top speed.
From www.twf8.ws
" Tuned Pipes - Or how the Resonance Effect is affecting Performance"
We all know that the exhaust pipe and the length of the manifold have an
effect on our engine's power output, but how exactly does it work?
First, imagine an engine with all ports, like the one below:
http://www.twf8.ws/new/tech/tip/setup/twostroke.gif
In our two-stroke engines, the intake port and the exhaust port are open at
the same time. This means that the amount of fresh mixture that can be
trapped in the combustion chamber is limited. An engine produces the more power
the more fuel/air mixture detonates.
Thus, our goal is to increase the amount of fresh mixture burnt during each cycle.
To do so, we need something that prevents the fresh mixture from leaving the
combustion chamber unburnt.
http://www.twf8.ws/new/tech/tip/setup/backpressure.gif
You see that the burnt exhaust gases form a pressure wave
which goes to the end of the pipe (or the baffle), then
reverses direction and prevents the fresh mixture from leaving
the combustion chamber. This walve is called back pressure.
So, knowing all this, how can I improve my buggy engine's performance?
What you can do to tune the exhaust system to your liking is to change the
length of the exhaust (distance from engine's exhaust port to pipe's baffle).
You can normally tune that by adjusting the length of the coupler (connecting
tube between manifold and pipe). Making it longer means that the pressure
wave takes longer to come back. The result is better performance at low revs,
that's more bottom end, acceleration. Having a shorter exhaust means that
the pressure wave is back faster, so you have the resonance effect in the high
revs. The result is additional top speed.
From www.twf8.ws
just kidding. Well kind of.
