Knowing which parameters to monitor with the Accessport can help determine if that’s the case. Generally, Dynamic Advance Multiplier (DAM), Feedback Knock Correction, and Fine Knock Learning are relevant when monitoring knock. DAM represents a global adjustment to ignition timing.
Is fine knock learn normal?
According to Cobb, DAM of 0.6 to 1 is normal, and fine knock learn and feedback knock of 0 to -4 is also normal on the 2015+ WRX.
What should my dam be?
A normal and healthy engine running normal and healthy fuel should have a DAM that is 1.0 for 32 Bit ECUs and 16 for 16 Bit ECUs. An exception to this is immediately after the ECU is reset, the DAM will be set LOWER THAN the maximum value (0.5 OR 12) for the OEM map and allowed to increment when the car is driven.
What causes dam to drop?
As the DAM was intended for Octane adjustment, the primary cause of the DAM dropping on a stock motor is likely fuel quality. HOWEVER, chronic DAM scaling can be indicative of vacuum leaks or even oil dilution.
What should AF correction 1 be at?
Af learning 1 varies from ej to fa. This is your real time fuel trim. For the ej platform values -8 to +8 while the engine is under load are acceptable. For the FA values -16 to +16 are acceptable (sourced by speaking to Ian at Maperformance who spoke with cobb), however values of -8 to +8 may be considered normal.
Should I worry about fine knock learn?
Under a quality tune, you should therefore NEVER have any Fine Learning Knock Correction. If you do experience it, it’s likely because you have too much timing, or your AFR is off and you’re running a bit too lean. In your case it looks like this happens as your turbo is spooling.
How much knock is normal?
Typically 0.5 degrees is a good starting point. If you are using multiple knock sensor on different banks of the engine (for example in a V6 or V8 application) then there are individual long term knock trim maps for each bank of the engine.
What does negative knock mean?
Negative “Knock” numbers mean that the PCM is detecting no detonation and ADDING Timing on its own.
What does DAM stand for Subaru?
Dynamic Advance Multiplier (DAM): This value represents a global adjustment to ignition timing. In general, this value is determined by historical detonation/knock as well as the default mapping value.
What does DAM stand for cars?
Generally, Dynamic Advance Multiplier (DAM), Feedback Knock Correction, and Fine Knock Learning are relevant when monitoring knock. DAM represents a global adjustment to ignition timing.
What is TD boost error?
TD Boost Error shows where your car is under or overboosting. Keep in mind, you also won’t always hit the requested boost pressure under every circumstance. For example this value isn’t very useful when you aren’t driving at full throttle.
Why do Subaru engines knock?
Detonation Knock
Most commonly, this is caused by using fuel with an insufficient octane rating for your car. If your vehicle requires premium fuel (such as a turbocharged Subaru WRX), this kind of knock can be caused by accidentally filling up the vehicle with regular grade fuel.
Is feedback knock okay?
In general, we consider Feedback Knock Correction ~-2.5 degrees or less to be “normal” and not of major concern.
Is knock bad?
Also known as engine ping or detonation, an engine knock is a sound and reaction that occurs when there is a second unplanned ignition or explosion within a cylinder that is separate from the regular controlled ignition from a spark plug. In other words, knock is bad news for your engine.
How can I control knocking?
Because pressure and temperature are strongly linked, knock can also be attenuated by controlling peak combustion chamber temperatures by compression ratio reduction, exhaust gas recirculation, appropriate calibration of the engine’s ignition timing schedule, and careful design of the engine’s combustion chambers and …
How do you stop engine knocking?
How to prevent engine knock?
- Retard Ignition Timing. Once the knock sensor receives the signal that knocking has started inside the cylinder, it sends the signal to the ECU. …
- High Octane Fuel. …
- Lower Compression Ratio. …
- Low Cylinder Temperature.
What is engine knock count?
#3 · Dec 23, 2015. Straight from Hondata. The knock count is increased each time the ECU determines that the knock sensor records a knock type event from the engine. The knock count is recorded for each individual cylinder. The knock recording of the ECU is not affected by altering the knock sensitivity tables.
What does a negative AF correction mean?
Negative values indicate fuel is being removed. … Positive values indicate fuel is being added as a result of the correction. Negative values indicate fuel is being removed. AF Learning 1 Idle 1 (AF Learning Idle1) -> Long-term (learned) fueling correction during idle conditions below the RPM breakpoint.
What does af learning mean?
A/F Learning 1
Positive numbers indicate that fuel is being added. Negative numbers indicate that fuel is being removed. The closer to zero the better, but generally, the acceptable range would be +/- 10%. Negative corrections beyond 10% mean the ECU is pulling lots of fuel.
What is AFR correction?
AFR Correction is how far the ECU is correcting from the base map. A negative number means that it is subtracting fuel and a positive number means that it is adding fuel. So in your case it is subtracting roughly 10% at idle to meet the AFR you input in the Air Fuel Ratios on the tablet.
What is a dam do?
A dam is a structure built across a stream or river to hold water back. Dams can be used to store water, control flooding, and generate electricity.
What causes knock WRX?
The Octane Level of Your Fuel Is Too Low
Premature combustion causes a knocking sound. While most Subaru models only require 87-octane fuel, some models like the WRX and the BRZ require higher-octane fuel. … If you notice this kind of knocking, buying an octane booster might help the issue.
What is a boost creep?
“Boost creep is a condition of rising boost levels past what the predetermined level has been set at. Boost creep is caused by a fully opened Wastegate(s) not being able to flow enough exhaust to bypass the housing via the Wastegate(s) itself.