FT500 SFI / FT500LITE SFI
55
Fuel tables adjust
Overall fuel trim
Bank B:
+ ,0
9
%
Main fuel injection table trim
+3,5
%
Bank A:
17.3 RPM compensation
This option is exclusive to the basic mode. The RPM compensation
is a percentage compensation applied to the main fuel table. The
calculation is automacally done considering the engine RPM and all
the other compensations. This way, a 3D table is not necessary, which
despite being more accurate, is harder then the basic mode and very
often doesn’t show a better result.
With the RPM compensation is possible to have a good tune in any
engine type, either a stock engine, race engine or with a variable
camshaft (Honda VTEC, Toyota VVT-i, BMW Vanos, etc).
Every engine has a specific fuel consumption peak around the maximum
torque rpm, so in the region additive compensation between 5 and
15% must be applied. In a stock engine the maximum torque is
normally between 2000rpm and 4500rpm, but to know exactly the
rpm a dinamometer is required. Anyway, this compensation will be
performed, because, to keep a constant AFR, more fuel will be needed
at the maximum torque rpm.
With the main fuel table and the RPM compensation, the ECU generates
internally a injection time vs load vs RPM table.
In all compensations the dead time must be discounted, so the value
can be related to amount of fuel, instead of pulse width purely.
RPM compensation
500 RPM
15
%
IMPORTANT
It is very important to check data continuity,
avoiding incoherent values that may produce
abrupt changes on the RPM graphic.
17.4 O2 Closed Loop
O2 closed loop reads O2 sensor and adds or removes fuel from the
main fuel table in order to reach the O2 target set up.
O2 cloed loop 4/9
λ
+
-
4000
RPM
3000
1,00
0,80
0,88
4250
0,88
0,90
0,80
0,88
0,75
1,00
0,90
0,80
bar
0,70
O2 closed loop 5/10
O2 closed loop on burnout, 3-step and 2-step
Disabled
Active, target map
Active, single value
Single value
0,75
λ
O2 closed loop 6/9
O2 closed loop on
idle by TPS
0,90
λ
General
Select O2 sensor position
Left bank
Right bank
Cylinder 1
Cylinder 2
O2 closed loop 4/11
Low load smoothness is the speed control for low load situations like
idle speed, where the O2 closed loop must reduce the compensation
for O2 variations.
Engine temperature for control start is a temperature limit below
which the O2 closed loop stays disabled and assumes the open loop
fuel tables
It is also possible to block the O2 closed loop under or above some
RPM limits. The “Lock below” parameter is used, i.e., on engines where
the O2 sensor is installed too close to the end of the exhaust, reading
free air below a certain RPM. The “Lock above” parameter is a limit to
disable the O2 closed loop and return to the open loop maps.
O2 cloed loop 4/9
λ
+
-
4000
RPM
3000
1,00
0,80
0,88
4250
0,88
0,90
0,80
0,88
0,75
1,00
0,90
0,80
bar
0,70
O2 closed loop 5/10
O2 closed loop on burnout, 3-step and 2-step
Disabled
Active, target map
Active, single value
Single value
0,75
λ
O2 closed loop 6/9
O2 closed loop on
idle by TPS
0,90
λ
