Question on BPW constant / switch
Thread Starter
Le Mans Master
Joined: Feb 2005
Posts: 6,475
Likes: 564
From: Clearwater Florida
Question on BPW constant / switch
In the constants and switches category on the 32B mask there is a switch for Base Pulse Width calibration method ( x = calc ) ... What is this for ? Will it affect or block changes made to the BPW vs Lv8 map ? And / or changes made to AE categories ? Which way should it be set ? It is currently x'ed ................
Safety Car
Joined: Sep 2001
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From: Glenbeulah Wi
That switch eliminates the automatic pulse width calculation from the computer and instead uses the BPW table to determine the base fueling before corrections. It is useful with cars that have very large cams and keep going rich at idle. The O2 sensor gets confused by the excessive oxygen in the exhaust and the computer keeps adding in fuel to eliminate the issue which in reality keeps making it richer. It also eliminates the max commanded pulse width that is programmed into these cars when you add in very large injectors. The stock calc mod limits the amount of fuel that can be added no matter how much fuel you are asking it to add, (to a max factory preset amount). If you run very large injectors and command a large fuel pulse the BPW mode eliminates this restriction and allows you to add in as much fuel as you want.
I use the BPW mode when I am tuning large cammed large injector cars that make lots of HP or use E85 fuel and make lots of HP.
I use the BPW mode when I am tuning large cammed large injector cars that make lots of HP or use E85 fuel and make lots of HP.
Thread Starter
Le Mans Master
Joined: Feb 2005
Posts: 6,475
Likes: 564
From: Clearwater Florida
That switch eliminates the automatic pulse width calculation from the computer and instead uses the BPW table to determine the base fueling before corrections. It is useful with cars that have very large cams and keep going rich at idle. The O2 sensor gets confused by the excessive oxygen in the exhaust and the computer keeps adding in fuel to eliminate the issue which in reality keeps making it richer. It also eliminates the max commanded pulse width that is programmed into these cars when you add in very large injectors. The stock calc mod limits the amount of fuel that can be added no matter how much fuel you are asking it to add, (to a max factory preset amount). If you run very large injectors and command a large fuel pulse the BPW mode eliminates this restriction and allows you to add in as much fuel as you want.
I use the BPW mode when I am tuning large cammed large injector cars that make lots of HP or use E85 fuel and make lots of HP.
I use the BPW mode when I am tuning large cammed large injector cars that make lots of HP or use E85 fuel and make lots of HP.
Safety Car
Joined: Sep 2001
Posts: 4,148
Likes: 544
From: Glenbeulah Wi
Thanks for the response ... however , I am still unclear as to which position the switch should be in to accomplish what you are suggesting above ... pardon my ignorance ... but switch on does what ? switch off does what ? What other settings are affected by each switch position ? For example : in TunerPro RT using the 32B XDF , I have a Base pulse width vs Lv8 and RPM chart ... which switch position accomodates changes made here .........
Advanced
Joined: Jun 2009
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From: St. Louis Missouri
I use tunercat so I am not 100% familar with the tunerPro settings. The switch should either turn on the base pulse width table or it should turn on the calc mode. If you want to use the BPW table you need to determine which switch setting turns on the table eliminates the calc mode.
I recently forced it to stay in open loop to avoid the idle going rich.
I will give this a try. thanks for the tip
Thread Starter
Le Mans Master
Joined: Feb 2005
Posts: 6,475
Likes: 564
From: Clearwater Florida
I use tunercat so I am not 100% familar with the tunerPro settings. The switch should either turn on the base pulse width table or it should turn on the calc mode. If you want to use the BPW table you need to determine which switch setting turns on the table eliminates the calc mode.
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Safety Car
Joined: Sep 2001
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From: Glenbeulah Wi
The computer caculates its own base pulse width based on the inputs received from all the sensors. The only thing that is effected in BPW mode is the base pulse width, all other tables are still used and they are added or subtracted to the BPW that is shown on the table. You are telling the car what BPW should be used for that load position and then all the table modifiers are added to that BPW.
Thread Starter
Le Mans Master
Joined: Feb 2005
Posts: 6,475
Likes: 564
From: Clearwater Florida
The computer caculates its own base pulse width based on the inputs received from all the sensors. The only thing that is effected in BPW mode is the base pulse width, all other tables are still used and they are added or subtracted to the BPW that is shown on the table. You are telling the car what BPW should be used for that load position and then all the table modifiers are added to that BPW.
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