ShelGame
11-01-2011, 10:27 AM
I originally posted this in bfaroo's 'lean tip in' thread and thought it deserved a thread of it's own...
Here's the best description of the PumpShot calculation I can give. This is valid for T-LM/SMEC/SBEC; it's a little more complicated for the T3 stuff.
Pumpshot Calculations:
There are 2 Pumpshot calculations: MAP-based and TPS-based.
MAP-Based PumpShotPW:
AvgMAP --> AETIME is the time constant for the AvgMAP calculation. A higher time constant gives a longer-term average (and usually a higher DeltaMAP - see the next definition).
DeltaMAP --> DeltaMAP is the difference between the current MAP value and the calculated average MAP (AvgMAP). [DeltaMAP = MAP - AvgMAP]
PumpShotPW Calculation:
If DeltaMAP is less than MAPTRG then there is no MAP PumpShot;
If DeltaMAP is greater than MAPTRG and lower than MAPMAX, then use DeltaMAP in the PW calculation;
If DeltaMAP is greater than MAPMAX, then substitute MAPMAX for DeltaMAP in the PW calculation (DeltaMAP = MAPMAX);
Lookup the value from the AESLOP table (from coolant temp);
[PumpShotPW(MAP) = AESLOP_valule X DeltaMAP]
TPS-Based PumpShotPW:
AvgTPS --> THRTCN is the time constant for the AvgTPS calculation. A higher time constant gives a longer-term average (and usually a higher DeltaTPS - see the next definition).
DeltaTPS --> DeltaTPS is the difference between the current TPS value and the calculated average TPS (AvgTPS). [DeltaTPS = TPS - AvgTPS]
PumpShotPW Calculation:
If DeltaTPS is less than POSTRG then there is no TPS PumpShot;
If DeltaTPS is greater than POSTRG and lower than THRMAX, then use DeltaTPS in the PW calculation;
If DeltaTPS is greater than THRMAX, then substitute THRMAX for DeltaTPS in the PW calculation (DeltaTPS = THRMAX);
Lookup the value from the POSSLP table (from coolant temp);
[PumpShotPW(TPS) = POSSLP_valule X DeltaTPS]
I know it's still pretty complicated.
For a bigger TB, I would actually start with the POSSLP table. Add PW in the operating temp range.
Reducing THRTCN would actually have the effect of reducing the pumpshot, I think, because it would reduce the DeltaTPS value. Increasing THRTCN should also increase the PumpShot, as would increasing THRMAX.
If increasing POSSLP doesn't seem to help, try increasing THRMAX, too.
Similarly, for a heavily ported head, I would adjust the AESLOP table. Add PW in the operating temp range.
Reducing AETIME would actually have the effect of reducing the pumpshot, because it would reduce the DeltaMAP value. Increasing AETIME should also increase the PumpShot, as would increasing MAPMAX.
I think I'll add a sub-group to the MP Tuner templates to separate the PumpShot functions from the lean-out functions...
Here's the best description of the PumpShot calculation I can give. This is valid for T-LM/SMEC/SBEC; it's a little more complicated for the T3 stuff.
Pumpshot Calculations:
There are 2 Pumpshot calculations: MAP-based and TPS-based.
MAP-Based PumpShotPW:
AvgMAP --> AETIME is the time constant for the AvgMAP calculation. A higher time constant gives a longer-term average (and usually a higher DeltaMAP - see the next definition).
DeltaMAP --> DeltaMAP is the difference between the current MAP value and the calculated average MAP (AvgMAP). [DeltaMAP = MAP - AvgMAP]
PumpShotPW Calculation:
If DeltaMAP is less than MAPTRG then there is no MAP PumpShot;
If DeltaMAP is greater than MAPTRG and lower than MAPMAX, then use DeltaMAP in the PW calculation;
If DeltaMAP is greater than MAPMAX, then substitute MAPMAX for DeltaMAP in the PW calculation (DeltaMAP = MAPMAX);
Lookup the value from the AESLOP table (from coolant temp);
[PumpShotPW(MAP) = AESLOP_valule X DeltaMAP]
TPS-Based PumpShotPW:
AvgTPS --> THRTCN is the time constant for the AvgTPS calculation. A higher time constant gives a longer-term average (and usually a higher DeltaTPS - see the next definition).
DeltaTPS --> DeltaTPS is the difference between the current TPS value and the calculated average TPS (AvgTPS). [DeltaTPS = TPS - AvgTPS]
PumpShotPW Calculation:
If DeltaTPS is less than POSTRG then there is no TPS PumpShot;
If DeltaTPS is greater than POSTRG and lower than THRMAX, then use DeltaTPS in the PW calculation;
If DeltaTPS is greater than THRMAX, then substitute THRMAX for DeltaTPS in the PW calculation (DeltaTPS = THRMAX);
Lookup the value from the POSSLP table (from coolant temp);
[PumpShotPW(TPS) = POSSLP_valule X DeltaTPS]
I know it's still pretty complicated.
For a bigger TB, I would actually start with the POSSLP table. Add PW in the operating temp range.
Reducing THRTCN would actually have the effect of reducing the pumpshot, I think, because it would reduce the DeltaTPS value. Increasing THRTCN should also increase the PumpShot, as would increasing THRMAX.
If increasing POSSLP doesn't seem to help, try increasing THRMAX, too.
Similarly, for a heavily ported head, I would adjust the AESLOP table. Add PW in the operating temp range.
Reducing AETIME would actually have the effect of reducing the pumpshot, because it would reduce the DeltaMAP value. Increasing AETIME should also increase the PumpShot, as would increasing MAPMAX.
I think I'll add a sub-group to the MP Tuner templates to separate the PumpShot functions from the lean-out functions...