Fuel cells questions????
Re: Fuel cells questions???? Fuel Cell info can be seen by simply logging it on autotap along with other data.
LS1 Edit cannot change your fueling maps specific to the individual fuel cells. Instead, we have to make block adjustments to the entire fueling schedule of the car via the injector flow rate table, MAF table, PE table, fuel-air multiplier table, Volumetric Efficiency tables, and IAC tables.
Each table is specific for certian situations of the car. For example
Injector Flow Rate Table: Changes fueling for all applications
MAF Table: Changes fueling for all close loop and WOT fueling (has side effects though)
PE Table: Changes fueling for WOT only.
Fuel Air Multiplier: Changes fueling for open loop upon start-up and "limp home" mode
Volumetric Efficiency Table: Changes fueling for all open loop fueling (has side effects though)
IAC Tables: Changes fueling for idle, park, neutral, "in gear" condition.
You need to determine where you want to adjust your fueling, and then make the changes to the necessary tables.
Good Luck,
Kevin
LS1 Edit cannot change your fueling maps specific to the individual fuel cells. Instead, we have to make block adjustments to the entire fueling schedule of the car via the injector flow rate table, MAF table, PE table, fuel-air multiplier table, Volumetric Efficiency tables, and IAC tables.
Each table is specific for certian situations of the car. For example
Injector Flow Rate Table: Changes fueling for all applications
MAF Table: Changes fueling for all close loop and WOT fueling (has side effects though)
PE Table: Changes fueling for WOT only.
Fuel Air Multiplier: Changes fueling for open loop upon start-up and "limp home" mode
Volumetric Efficiency Table: Changes fueling for all open loop fueling (has side effects though)
IAC Tables: Changes fueling for idle, park, neutral, "in gear" condition.
You need to determine where you want to adjust your fueling, and then make the changes to the necessary tables.
Good Luck,
Kevin
Re: Fuel cells questions???? What side effects are there for editting the MAF table (bumping it up 10%) <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" /> Other then getting fuel trims down?
<small>[ November 21, 2002, 04:20 PM: Message edited by: ChrisV 02 - Z28 ]</small>
<small>[ November 21, 2002, 04:20 PM: Message edited by: ChrisV 02 - Z28 ]</small>
Staging Lane
Joined: Aug 2002
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From: Plano, Texas
Re: Fuel cells questions???? When you increase your MAF table, you assign a higher grams/second value at a given rpm.
That, in turn, is used to calculate the grams/cylinder value that determines the timing value the car will use (see High Octane table), typically lowering the timing, as grams/cylinder and rpm increases.
That, in turn, is used to calculate the grams/cylinder value that determines the timing value the car will use (see High Octane table), typically lowering the timing, as grams/cylinder and rpm increases.
TECH Regular
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Re: Fuel cells questions???? Has anybody tried adjusting high load spark curves after MAF scaling ?
My LTRIMs are around -4 for fuel cell 0 and gradually increase to around +5 for cells above 7. Would block scaling of MAF table work ?
Also, how are the on-gear and rolling part throttle fuel cells decided by PCM ?
My LTRIMs are around -4 for fuel cell 0 and gradually increase to around +5 for cells above 7. Would block scaling of MAF table work ?
Also, how are the on-gear and rolling part throttle fuel cells decided by PCM ?
Re: Fuel cells questions???? Yes, you can increase the timing curve after you modify the MAF curve, but rather than spend the time modifying both it is just easier to leave the MAF curve alone and play with the injector flow rate table instead.
The GM timing table is pretty accurate for lightly modified cars, and it is best to keep the trends that they have already set in to the timing. Heavily modifying the MAF curve throws all of this out of whack.
The GM timing table is pretty accurate for lightly modified cars, and it is best to keep the trends that they have already set in to the timing. Heavily modifying the MAF curve throws all of this out of whack.
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Re: Fuel cells questions???? Can you give any brief description on how to target particular fuel cells with injector flow rate table ? How to prevent extra fuel @WOT while scaling for LTRIMs this way ? Using PE table ?
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Re: Fuel cells questions???? It is best to tune Part-throttle Lterms by makeing block adjustments to the Injector Flow Table then do WOT via the PE table. This in my opinion is the "right" way to do it and will ensure the least amount of tuning complications in the future.
To answer your question though:
You can make specific adjustments to individual injector flow rate cells to obtain desired results.
Here is generally what your car is doing for specific MAP. MAP is a direct function of TPS and RPM
0 - 10: WOT
15 - 35: Spirited Driving / Transient
40 - 50: Highway / Mid RPM Driving
55 - 75: Idle / Low RPM Driving / Around Town
80+: Deceleration
Like I said above though. It is best to make block adjustments to the Injector Flow Table, THEN tune WOT with the PE table.
Good Luck,
Kevin
To answer your question though:
You can make specific adjustments to individual injector flow rate cells to obtain desired results.
Here is generally what your car is doing for specific MAP. MAP is a direct function of TPS and RPM
0 - 10: WOT
15 - 35: Spirited Driving / Transient
40 - 50: Highway / Mid RPM Driving
55 - 75: Idle / Low RPM Driving / Around Town
80+: Deceleration
Like I said above though. It is best to make block adjustments to the Injector Flow Table, THEN tune WOT with the PE table.
Good Luck,
Kevin
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TECH Apprentice
Joined: Jan 2002
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From: Murphy, TX
Re: Fuel cells questions???? </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by pekkaz:
<strong>Also, how are the on-gear and rolling part throttle fuel cells decided by PCM?</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">FTC (0-15) is determined by MAP and RPM.
<strong>Also, how are the on-gear and rolling part throttle fuel cells decided by PCM?</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">FTC (0-15) is determined by MAP and RPM.
TECH Regular
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Re: Fuel cells questions???? Thanks guys, I just put a new fuel filter in and will do some ATAP again to check if something changed.
If I don't scale MAP 0-10, does that mean it does not change WOT fueling ? Is there one to one mapping between these numbers and the table ?
If I don't scale MAP 0-10, does that mean it does not change WOT fueling ? Is there one to one mapping between these numbers and the table ?
Re: Fuel cells questions???? I'm not sure what you mean by 1 to 1 mapping?
If you change your injector flow table for all points other than 0 to 10, then yes your WOT fueling will remain unchanged.
A word of advice though. If your Injector Flow Table has too large of a step (ie there is a 20% difference between the 0-10 MAP and the rest) you can end up causing your car to either hesitate or bog when going WOT. This is another reason it is best to stick with the PE table for WOT tuning.
Good Luck,
Kevin
If you change your injector flow table for all points other than 0 to 10, then yes your WOT fueling will remain unchanged.
A word of advice though. If your Injector Flow Table has too large of a step (ie there is a 20% difference between the 0-10 MAP and the rest) you can end up causing your car to either hesitate or bog when going WOT. This is another reason it is best to stick with the PE table for WOT tuning.
Good Luck,
Kevin
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Re: Fuel cells questions???? Kevin, by 1 to 1 mapping I ment does for example 0-10 in your post map to 0-10 in the flow rate table or do you have to map it somehow. I suppose the mapping is direct( 1 to 1 ).
How about PE vs. flow rate scaling, if you scale WOT flow rate by, say 97%, will the scaling of PE table by 97% maintain WOT a/f ?
Thanks,
Pekka
How about PE vs. flow rate scaling, if you scale WOT flow rate by, say 97%, will the scaling of PE table by 97% maintain WOT a/f ?
Thanks,
Pekka
Re: Fuel cells questions???? By 0-10, I am talking about the number along the upper row. The numbers by which your injector flow numbers are organized. This is your MAP or Manifold Air Pressure. The second row of numbers is the g/sec that your injectors flow for that Manifold Pressure.
Power Enrichment is a calculated increase in fuel delivery for WOT. The way the numbers work, a 3% increase in the P.E. table is suppose to be a 3% decrease in WOT a/f. However, in reality it doesn't work that way. As a rule of thumb a 2-3% increase in the P.E. table is equal to 1 a/f point.
For example (on a stock car)
PE value of 1.2403 is equal to about 11.9 a/f ratio
PE value of 1.2403 * .98 is equal to about 12.9 a/f
The injector flow table does not operate on the same principle. You have to "mess" with the table is small percentage steps.
<small>[ November 26, 2002, 08:13 AM: Message edited by: NoGo ]</small>
Power Enrichment is a calculated increase in fuel delivery for WOT. The way the numbers work, a 3% increase in the P.E. table is suppose to be a 3% decrease in WOT a/f. However, in reality it doesn't work that way. As a rule of thumb a 2-3% increase in the P.E. table is equal to 1 a/f point.
For example (on a stock car)
PE value of 1.2403 is equal to about 11.9 a/f ratio
PE value of 1.2403 * .98 is equal to about 12.9 a/f
The injector flow table does not operate on the same principle. You have to "mess" with the table is small percentage steps.
<small>[ November 26, 2002, 08:13 AM: Message edited by: NoGo ]</small>
Re: Fuel cells questions???? </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Kevin V 2002 SS:
<strong>In Auto Tap or LS1 Edit, other than monitoring "which" cell it is in, where can you view or revise what the parameters are "in" the cells.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">We cannot make specific adjustments to the fuel cell maps (specific fueling tables applied for different fuel cells) other than Fuel Cell 22. Fuel Cell 22 can be modified with the P.E. table.
Fuel Cell 22 is a suedo open loop operation that is applied at WOT and a few other occasions.
<strong>In Auto Tap or LS1 Edit, other than monitoring "which" cell it is in, where can you view or revise what the parameters are "in" the cells.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">We cannot make specific adjustments to the fuel cell maps (specific fueling tables applied for different fuel cells) other than Fuel Cell 22. Fuel Cell 22 can be modified with the P.E. table.
Fuel Cell 22 is a suedo open loop operation that is applied at WOT and a few other occasions.
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Re: Fuel cells questions???? </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">where can you view or revise what the parameters are "in" the cells </font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">To view you need to log current fuel cell and parameters you want to look at. Take a 15 minute drive using variable loads. Then dump the data out and sort by fuel cell in a program of your choice. Don't log many parameters at the same time, even then you may need to discard some values because of obvious glitches.