When is VE in control vs. MAF?
03-12-2007, 02:59 PM
#31
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Originally Posted by 12secSS
By allow the ECM to add extra enrichment for harsh throttle transitions, you allow more fuel to stay in the mixture or add extra fuel caused by the vaporized fuel that has now been condense and is no longer atomized. This can also be adjusted, depending on the OS, for how long the extra enrichment is applied. I hope this helps. 
03-13-2007, 03:47 AM
#32
Originally Posted by 12secSS
Sorry to bring up an "old" thread, but this can be helpful to this topic.
To remedy that instant lean factor when you mash the throttle, you need to adjust the fuel transient tables. Some of these table depic the pool of extra fuel left over, that the ECM uses during harsh throttle transitions. This fuel, under low pressure, tends boil over easily and allows enrichment. But when you add pressure (open the throttle) and vacuum drops (N/A) or boost rises (FI), it causes the vaporized fuel to rain on the intake port. This causes the inital lean condition you exprience. By allow the ECM to add extra enrichment for harsh throttle transitions, you allow more fuel to stay in the mixture or add extra fuel caused by the vaporized fuel that has now been condense and is no longer atomized. This can also be adjusted, depending on the OS, for how long the extra enrichment is applied. I hope this helps.
To remedy that instant lean factor when you mash the throttle, you need to adjust the fuel transient tables. Some of these table depic the pool of extra fuel left over, that the ECM uses during harsh throttle transitions. This fuel, under low pressure, tends boil over easily and allows enrichment. But when you add pressure (open the throttle) and vacuum drops (N/A) or boost rises (FI), it causes the vaporized fuel to rain on the intake port. This causes the inital lean condition you exprience. By allow the ECM to add extra enrichment for harsh throttle transitions, you allow more fuel to stay in the mixture or add extra fuel caused by the vaporized fuel that has now been condense and is no longer atomized. This can also be adjusted, depending on the OS, for how long the extra enrichment is applied. I hope this helps.
03-13-2007, 10:06 AM
#33
Guys,
At the moment I have played with these values only. I adjust them in small quantities and test the initial hit of the throttle, trying to lessen the AFR spike (verified by my wideband). But I was told about them from people I regard as experts in the field (quite a few to list). Definately it is based on the injector design, which I would like to see a more robust injector spreadsheet (hint hint Marcin 
) that uses the injector specs and converts that data to minimum pulse width, offsets, etc ... Currently some injector info is hard to come by. 
Seems like this (fuel transient tables) are an uncharted territory for DIYer's.
At the moment I have played with these values only. I adjust them in small quantities and test the initial hit of the throttle, trying to lessen the AFR spike (verified by my wideband). But I was told about them from people I regard as experts in the field (quite a few to list).
Definately it is based on the injector design, which I would like to see a more robust injector spreadsheet (hint hint Marcin ) that uses the injector specs and converts that data to minimum pulse width, offsets, etc ... Currently some injector info is hard to come by. Seems like this (fuel transient tables) are an uncharted territory for DIYer's.
03-13-2007, 11:12 AM
#35
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Originally Posted by 12secSS
Guys,
At the moment I have played with these values only. I adjust them in small quantities and test the initial hit of the throttle, trying to lessen the AFR spike (verified by my wideband). But I was told about them from people I regard as experts in the field (quite a few to list). Definately it is based on the injector design, which I would like to see a more robust injector spreadsheet (hint hint Marcin ) that uses the injector specs and converts that data to minimum pulse width, offsets, etc ... Currently some injector info is hard to come by. Seems like this (fuel transient tables) are an uncharted territory for DIYer's.
At the moment I have played with these values only. I adjust them in small quantities and test the initial hit of the throttle, trying to lessen the AFR spike (verified by my wideband). But I was told about them from people I regard as experts in the field (quite a few to list).
Definately it is based on the injector design, which I would like to see a more robust injector spreadsheet (hint hint Marcin ) that uses the injector specs and converts that data to minimum pulse width, offsets, etc ... Currently some injector info is hard to come by. Seems like this (fuel transient tables) are an uncharted territory for DIYer's. if you know how it works, and at least have some mockup data to play with, i'd be more than happy make a new spreadsheet, but as of right now i just dont know how this stuff works. plus, my school is really getting in the way of my education...
if you got anything on these topics, email me or something, we need this badly, i hate hacking numbers blind without understanding
03-13-2007, 11:40 AM
#36
Originally Posted by dc_justin
That's my kind of territory.
Originally Posted by RedHardSupra
recently i came upon some math that could get us things like minimal pulse width and offsets, but we'd still need data. i'm talking with one company to get us more precise info, but that's nothing sure yet.
if you know how it works, and at least have some mockup data to play with, i'd be more than happy make a new spreadsheet, but as of right now i just dont know how this stuff works. plus, my school is really getting in the way of my education...
if you got anything on these topics, email me or something, we need this badly, i hate hacking numbers blind without understanding
if you know how it works, and at least have some mockup data to play with, i'd be more than happy make a new spreadsheet, but as of right now i just dont know how this stuff works. plus, my school is really getting in the way of my education...
if you got anything on these topics, email me or something, we need this badly, i hate hacking numbers blind without understanding
I found a website that had an extensive list of injectors and some data, I will find it and forward it to you (could be you have stumbled upon it). I will ask those that I know (as well as make a post on the HPT forum), of how it works and relay that info to the enthusiasts. I agree about playing with numbers, I much prefer to understand their function then mearly adjusting them.Good luck with your schooling.
03-20-2007, 10:06 PM
#37
Originally Posted by 12secSS
Sorry to bring up an "old" thread, but this can be helpful to this topic.
To remedy that instant lean factor when you mash the throttle, you need to adjust the fuel transient tables. Some of these table depic the pool of extra fuel left over, that the ECM uses during harsh throttle transitions. This fuel, under low pressure, tends boil over easily and allows enrichment. But when you add pressure (open the throttle) and vacuum drops (N/A) or boost rises (FI), it causes the vaporized fuel to rain on the intake port. This causes the inital lean condition you exprience. By allow the ECM to add extra enrichment for harsh throttle transitions, you allow more fuel to stay in the mixture or add extra fuel caused by the vaporized fuel that has now been condense and is no longer atomized. This can also be adjusted, depending on the OS, for how long the extra enrichment is applied. I hope this helps.
To remedy that instant lean factor when you mash the throttle, you need to adjust the fuel transient tables. Some of these table depic the pool of extra fuel left over, that the ECM uses during harsh throttle transitions. This fuel, under low pressure, tends boil over easily and allows enrichment. But when you add pressure (open the throttle) and vacuum drops (N/A) or boost rises (FI), it causes the vaporized fuel to rain on the intake port. This causes the inital lean condition you exprience. By allow the ECM to add extra enrichment for harsh throttle transitions, you allow more fuel to stay in the mixture or add extra fuel caused by the vaporized fuel that has now been condense and is no longer atomized. This can also be adjusted, depending on the OS, for how long the extra enrichment is applied. I hope this helps.
03-21-2007, 09:41 PM
#38
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Originally Posted by dewmanshu
I don't see these tables in HPT. (2002 and 2003 trucks) I see the transient tab. But nothing there. ARGHGHGHGHGHGHG!!!!!!
03-21-2007, 11:00 PM
#39
Originally Posted by 1slowsilverado
Are you sure about the 02? http://i59.photobucket.com/albums/g2.../Transient.jpg
03-21-2007, 11:31 PM
#40
Originally Posted by RedHardSupra
recently i came upon some math that could get us things like minimal pulse width and offsets, but we'd still need data. i'm talking with one company to get us more precise info, but that's nothing sure yet.
if you know how it works, and at least have some mockup data to play with, i'd be more than happy make a new spreadsheet, but as of right now i just dont know how this stuff works. plus, my school is really getting in the way of my education...
if you got anything on these topics, email me or something, we need this badly, i hate hacking numbers blind without understanding
if you know how it works, and at least have some mockup data to play with, i'd be more than happy make a new spreadsheet, but as of right now i just dont know how this stuff works. plus, my school is really getting in the way of my education...
if you got anything on these topics, email me or something, we need this badly, i hate hacking numbers blind without understanding
RIck