TUNING MAFLESS ?

[hpcubed]

Another question: With the maf disabled, the "idle airflow" parameters will be ignored? The computer is only using the VE table for air mass?

[jfpilla]

Another question: With the maf disabled, the "idle airflow" parameters will be ignored? The computer is only using the VE table for air mass?

No, they continue to function.

[hpcubed]

Another question: With the maf disabled, the "idle airflow" parameters will be ignored? The computer is only using the VE table for air mass?

No, they continue to function.

Ok, I understand the "effective area" is used and not maf.

So why do you think my car is idleing so rich when I unplug the maf? Is the VE table off or should I look elsewhere?

[jfpilla]

Another question: With the maf disabled, the "idle airflow" parameters will be ignored? The computer is only using the VE table for air mass?

No, they continue to function.

Ok, I understand the "effective area" is used and not maf.

So why do you think my car is idleing so rich when I unplug the maf? Is the VE table off or should I look elsewhere?

It's very likely the VE's. I'm assuming you are cammed. Start by lowering the VE's at 1200 by 15% 800 by 10% 400by 5%. That's to get you running well enough to log. Set your trims negative, using the VE table, then hook up the MAF. Reset the trims through the MAF table.
If you have stock injectors leave the IFRs stock. That will allow you to calculate your PE values.

Suggest you list your mods when asking for help.

[hpcubed]

Another question: With the maf disabled, the "idle airflow" parameters will be ignored? The computer is only using the VE table for air mass?

No, they continue to function.

Ok, I understand the "effective area" is used and not maf.

So why do you think my car is idleing so rich when I unplug the maf? Is the VE table off or should I look elsewhere?

It's very likely the VE's. I'm assuming you are cammed. Start by lowering the VE's at 1200 by 15% 800 by 10% 400by 5%. That's to get you running well enough to log. Set your trims negative, using the VE table, then hook up the MAF. Reset the trims through the MAF table.
If you have stock injectors leave the IFRs stock. That will allow you to calculate your PE values.

Suggest you list your mods when asking for help.

Thanks for the info jfpilla I will try what you suggest. Mods are now listed. I have been studying for about a month now and I think I got a pretty good handle on a lot of this stuff. But I don't quite understand what you meant by calculating the PE values if the IFR's are stock. How do you calculate the PE values? I thought that was determined by wideband or stock O2's?

[jfpilla]

Another question: With the maf disabled, the "idle airflow" parameters will be ignored? The computer is only using the VE table for air mass?

No, they continue to function.

Ok, I understand the "effective area" is used and not maf.

So why do you think my car is idleing so rich when I unplug the maf? Is the VE table off or should I look elsewhere?

It's very likely the VE's. I'm assuming you are cammed. Start by lowering the VE's at 1200 by 15% 800 by 10% 400by 5%. That's to get you running well enough to log. Set your trims negative, using the VE table, then hook up the MAF. Reset the trims through the MAF table.
If you have stock injectors leave the IFRs stock. That will allow you to calculate your PE values.

Suggest you list your mods when asking for help.

Thanks for the info jfpilla I will try what you suggest. Mods are now listed. I have been studying for about a month now and I think I got a pretty good handle on a lot of this stuff. But I don't quite understand what you meant by calculating the PE values if the IFR's are stock. How do you calculate the PE values? I thought that was determined by wideband or stock O2's?

If your injector flow rate table has stock values and you have stock injectors, you can calculate your desired PE rpm. If you divide 14.7 by the desired AFR you get the value for PE modifier rmp in mixture tab.
EX:14.7/13.0=1.13(modifier) 14.7/12.6=1.167

[GMPX]

If your injector flow rate table has stock values and you have stock injectors, you can calculate your desired PE rpm. If you divide 14.7 by the desired AFR you get the value for PE modifier rmp in mixture tab.
EX:14.7/13.0=1.13(modifier) 14.7/12.6=1.167

Or in the properties list in the Tuner select to view these values as AFR, not EQ.

Cheers,
Ross

[hpcubed]

Leaned out the mixture as jfpilla suggested and now the car idles fine. So now I am off and tuning.

Thanks.

[jfpilla]

If your injector flow rate table has stock values and you have stock injectors, you can calculate your desired PE rpm. If you divide 14.7 by the desired AFR you get the value for PE modifier rmp in mixture tab.
EX:14.7/13.0=1.13(modifier) 14.7/12.6=1.167

Or in the properties list in the Tuner select to view these values as AFR, not EQ.

Cheers,
Ross

Ross,
Nice feature. I can put the calculator away.
thanks
Joe

[hpcubed]

Did some logging. My trims are all in the -9 to -15's in the lower half of the map values. I can understand my volumetric efficiency being lower than a stock cam at low rpms but it seems that by 4000 rpm, the engines VE should be better than stock? Is this typical for a heads/cam engine?