DO TORQUE CONES WORK??
No they dont work. You are F%$^%& up the cylinder fill.
This how an exhaust system works.
"Dt" will be around 0.45 x Piston diameter for high revs and 0.5 x Piston diameter for torque.
This how an exhaust system works.
(A) Primary Pipe.
Often a parallel tube, particularly in cheaper production road machines, but ideally a tapered
primary pipe should be used to control the expansion rate of the high speed gas slug ejected
from the port and to convert its kinetic energy into pressure energy.
70
Often a parallel tube, particularly in cheaper production road machines, but ideally a tapered
primary pipe should be used to control the expansion rate of the high speed gas slug ejected
from the port and to convert its kinetic energy into pressure energy.
70
(B) Primary Divergent Cone.
Controls initial expansion of the pressure pulse and is often combined with :
(C) Secondary Divergent Cone.
Which finally controls the pressure pulse expansion to
induce the negative pulse, which travels back to the port
to help scavenge the cylinder.
(D) Expansion Chamber.
Length acts as a time control before throttling of the gas
slug which starts at :
(E) Convergent Cone.
Which throttles down the slug to the :
(F) Tail Pipe.
The size of which controls the high back pressure reverse
"plug", which in turn pushes the overspill of intake charge
back into the cylinder before the piston shuts the door.
The whole sequence, using correctly designed
components, will result in a cylinder filling efficiency of
more than 100% at the "tuned" engine speed.
True design formulae for these systems are highly
complex and still not quite fully understood, but outlined
below is a simplified starting point for those who want to
have a go themselves :
41910 x TD
Length "G" in mms = ----------
R.P.M.
Where TD is transfer port duration in degrees.
R.P.M. is desired "on pipe" R.P.M.
41910 x ED
Length "H" in mms = ----------
R.P.M.
Where "ED" is exhaust port duration in degrees.
41910 x (TD + C)
Length "J" in mms = ---------------
R.P.M.
Where "C" will control the length of the parallel section
and lengthen time before reverse plug starts.
Find this empirically by starting at 0 and increasing in intervals of 5.
"De" will be around 2.25 x Piston diameter for high revs and 2.0 x Piston diameter for torque.
Controls initial expansion of the pressure pulse and is often combined with :
(C) Secondary Divergent Cone.
Which finally controls the pressure pulse expansion to
induce the negative pulse, which travels back to the port
to help scavenge the cylinder.
(D) Expansion Chamber.
Length acts as a time control before throttling of the gas
slug which starts at :
(E) Convergent Cone.
Which throttles down the slug to the :
(F) Tail Pipe.
The size of which controls the high back pressure reverse
"plug", which in turn pushes the overspill of intake charge
back into the cylinder before the piston shuts the door.
The whole sequence, using correctly designed
components, will result in a cylinder filling efficiency of
more than 100% at the "tuned" engine speed.
True design formulae for these systems are highly
complex and still not quite fully understood, but outlined
below is a simplified starting point for those who want to
have a go themselves :
41910 x TD
Length "G" in mms = ----------
R.P.M.
Where TD is transfer port duration in degrees.
R.P.M. is desired "on pipe" R.P.M.
41910 x ED
Length "H" in mms = ----------
R.P.M.
Where "ED" is exhaust port duration in degrees.
41910 x (TD + C)
Length "J" in mms = ---------------
R.P.M.
Where "C" will control the length of the parallel section
and lengthen time before reverse plug starts.
Find this empirically by starting at 0 and increasing in intervals of 5.
"De" will be around 2.25 x Piston diameter for high revs and 2.0 x Piston diameter for torque.
"Dt" will be around 0.45 x Piston diameter for high revs and 0.5 x Piston diameter for torque.
Last edited by DRAGO'S BIKE WORKS; May 25, 2011 at 07:19 AM.
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