User Manual

THRO CURV – THROTTLE CURVE
An ideal throttle set up is linear in nature where ¼ stick results in ¼ RPM, ½ stick results in ½
RPM etc. However, many of today’s gas engines employ pumping carburetors which do not
produce a very linear response. Instead, they cause engine RPM to increase very rapidly from
low throttle up to about ½ throttle and then very slowly from ½ throttle to full throttle. When the
carb is open ½ way the engine may be running at 75%-90% of its maximum RPM. Obviously
not an ideal situation.
A linear throttle response can be obtained with the THRO CURV function by causing the throttle
servo to move in an exponential fashion. In other words, the servo will move very little for the
first ¼ - ½ of stick movement and then move more rapidly as the stick is advanced further.
When properly adjusted, the THRO CURV function will result in a linear throttle response
where there is a noticeable RPM change with each click of throttle stick movement.
THRO CURV can also be used to set up a special throttle response where the engine quickly
comes up to a certain RPM and then advances very slowly to provide precise RPM control for a
specific throttle range before continuing on to full throttle. Such a curve is useful for torque
rolling, rolling circles and other maneuvers where the throttle response is slowed or flattened-out
for a particular throttle range.
If the TWIN E function has been activated for twin-engine aircraft, independent throttle curves
are available for each engine to help eliminate any discrepancies in the throttle response between
the two engines.
Obtain the Throttle Curve function by selecting THRO CURV in the FUNCTION List.
Function
Name
ENT
LIST
CLR
Pos.0
L 1 2 3 4 5 H
[
THRO CURV
]
0
Position –
changes from 0
to 1 when switch
is moved
SW SELECT
THRO EXP
STK INH OFF
IN 50 OUT 50
Point-L
Point-1
Point-2
Point-3
Point-4
Point-5
Point-H
0.0%
INH
INH
50.0%
INH
INH
100.0%
Current
Point
setting
Throttle
Stick
Position
Throttle
Servo
Position
Current
Position being
viewed/set.
Will be RTH.0
if Twin Engine
is active
Throttle used
as switch
between
throttle
curves 0 & 1
Select Switch
to switch
between
throttle
curves 0 & 1
Exponential
ON/OFF
Points That Can Be Ad
j
usted
Cursor – Moves
with throttle
stick. Currently
at ½ throttle
Graph showing
throttle curve. X-
axis = throttle stick,
Y-axis=throttle
servo
C
curve is defined
urve/Line – the
by the values
set for the 7
points
JR XP9303 Detailed Function Descriptions 50