Can't remember where I got it but the open loop enleanment calculation looks like this:
correction_value = FRCSFT * ACT + (1-FRCSFT) * ECT
What is FRCSFT? Can't find an explanation anywhere.
Open Loop Fueling (FRCSFT)
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big_bertha
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decipha
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Re: Open Loop Fueling (FRCSFT)
You can see it in your math.
Its a percentage of act to ect to use for the input lookup value.
if FRCSFT == 1.0; 1.00 * ACT + ( [1-1]=0 * ECT == all ACT determines the input scaling
if FRCSFT == 0.5; 0.50 * ACT + ( [1-0.5]=0.5 * ECT == Half ACT and half ECT determines the input scaling
if FRCSFT == 0.0; 0.00 * ACT + ([1-0)=1 * ECT == all ECT determines the input scaling
so the temperature use for the lookup function is going to be a percentage of ACT to ECT determined by how much percentage you choose to you in that FRCSFT scalar.
On a cold start ECT and ACT is going to be identical so doesn't matter. But on hot starts ECT should be at full operating temp and ACT should be down near ambient (ideally) unless the IAT is in the plenum which would be nearer to ECT due to heat soak.
Ideally you can use all ECT for input scaling by setting the FRCSFT scalar to 0 which is how all never strategies function.
Its a percentage of act to ect to use for the input lookup value.
if FRCSFT == 1.0; 1.00 * ACT + ( [1-1]=0 * ECT == all ACT determines the input scaling
if FRCSFT == 0.5; 0.50 * ACT + ( [1-0.5]=0.5 * ECT == Half ACT and half ECT determines the input scaling
if FRCSFT == 0.0; 0.00 * ACT + ([1-0)=1 * ECT == all ECT determines the input scaling
so the temperature use for the lookup function is going to be a percentage of ACT to ECT determined by how much percentage you choose to you in that FRCSFT scalar.
On a cold start ECT and ACT is going to be identical so doesn't matter. But on hot starts ECT should be at full operating temp and ACT should be down near ambient (ideally) unless the IAT is in the plenum which would be nearer to ECT due to heat soak.
Ideally you can use all ECT for input scaling by setting the FRCSFT scalar to 0 which is how all never strategies function.