There have been numerous discussions on how the 4B11 ECU re-flash should be to maximize engine output. Here is a brief summary on how and the rationale for it. Rather than be immersed with the number of parameters to be changed during the 4B11 ECU re-flash, only a few will be considered as they are what matters most.
This write-up is applicable to those who leave their intakes and exhaust stock or replace them with aftermarket performance intakes and exhausts. Please note that all else is left status quo, for example, camshafts, fuel regulators, CVT programming and etc.
1. Advance Timing
Advancing timing yields a crisper response with more torque and a quicker rise in power delivery before MIVEC @ 4250rpm. However, there is a torque dip at 2500-2600rpm. After MIVEC @ 4250rpm, output gains of around 7-8bhp at the crank especially from 5500rpm – 6000rpm.
a) Via Valve Timing
The 4B11 re-flash must set the valve timing at the following values at all engine loads (rpm) by fixing the cam actuator to maximum advance.
Intake Valve
Open (BTDC) -25 Degrees
Close (ABDC) -23 Degrees
Exhaust Valve
Open (BBDC) -24 Degrees
Close (ATDC) -20 Degrees
The Valve Timing method can only advance the timing to the limits set by 4B11 camshafts. Beyond the -25 Degrees in the Intake Valve Open (BTDC) for example, is impossible.
b) Via Karmen Vortex Air-Flow Sensor (Intake Valve Only)
To advance the timing further beyond the -25 Degrees (BTDC) to -30 degrees, for example, the 4B11 re-flash must be able to manipulate the Karmen Vortex Air-Flow Sensor.
The recommended advance timing in this respect is 6 degrees, bringing the total advance timing in the example able to -31 Degrees for BTDC and –29 degrees for ABDC.
2. AFR
The 4B11 re-flash should manipulate the AFR on a tiered approach rather than a one size fits all approach. The OEM programming for the 4B11 is relatively lean below 3000rpm and thereafter rich (in the 12s).
Tier 1 AFR should manipulate the 3000-4250 rpm to be relatively lean, around 13.0 – 14.0 or at OEM levels. Tier 2 AFR should be richer around 12.3 – 12.8 (more so if timing is advanced).
3. Maximum Throttle Compensation - Fuel Tank Differential Pressure Sensor/Power Steering Sensor/Air Conditioning Sensor
Ever noticed that the 4B11 is more responsive and powerful when the tank is more than half empty? Obviously the vehicle is lighter, but test is removing mass to simulate a more than half empty fuel tank (while the tank is full) has shown that the performance was no better. The 4B11 re-flash should manipulate fuel tank differential pressure sensor to tell the ECU that the tank is more than half empty (higher pressure and more evaporation). This tells the Evaporative Emission Purge Solenoid to tell the throttle to make maximum compensation for emissions control.
For the Power Steering Sensor and the Air Conditioning Sensor, the 4B11 re-flash should manipulate these sensors so that maximum throttle compensation is enabled.
4. Soft Limiter
The 4B11 has a standard built in soft limiter at 200kmh. The 4B11 re-flash should remove it so that speed gains above 200kmh is faster.
5. Rpm Limiter
The 4B11 rpm limiter is set at 6125rpm. The 4B11 re-flash should limit it to 6000rpm. Real world results have shown that there engine output (power and torque) reduces significantly after 6000 rpm. In general, 4B11 maximum power in produced between 5900 – 6000rpm.
6. Throttle Response
The 4B11 re-flash should not alter the OEM throttle response beyond that of the throttle compensation levels. Real world results have shown that this does not increase the performance of the 4B11 or any other vehicles in any way whatsoever. Furthermore, the CVT ECU programming would override this throttle response and limit output to OEM levels.
7. MIVEC
The 4B11 re-flash should not alter the OEM MIVEC @ 4250rpm. Altering it does not yield more engine output. Furthermore, its power delivery does not match to the CVT ECU program. However, some may prefer the earlier power deliver at the expense of an earlier power taper at higher rpm. Real world results show that the performance gains are minimal at best.
Lancer Nation 
Home 
Latest images 
Register 
Log in 
