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View Full Version : Scaling MAF for Supercharged GM LS1



RamAir
December 27th, 2012, 01:40 AM
Has anyone tried to scale the MAF to be used in a supercharged application on a LS1 (with 12psi boost it does peg it early)? I would really like to increase the limit of 512g/sec but I think it is a software limit? Enabling the MAF instead of going speed Density provides better driveability and response over varying atmospheric conditions.

joecar
December 27th, 2012, 07:12 AM
The LS1B MAF limit of 512 g/s is in the PCM.

You would have to scale the IFR/MAF/VE down by the same factor, and you would have to shift any tables that reference airmass or airflow.

RamAir
January 4th, 2013, 02:49 AM
Can EFILive change the MAF hard limit of 512g/s in the PCM? This would really be great because for those cars that have a blower, we would not have to try to scale everything or go to speed density.

joecar
January 4th, 2013, 07:14 AM
No, it's a limitation of the PCM hardware.

correction: it's a limitation in the OS/code section as Greg says in the next post below.

eficalibrator
January 7th, 2013, 02:51 AM
You can't change the 512g/s limit, as this is in the code section, not the calibration data. However, it is possible to scale your calibration data down to stay under the code's limitations and still have a perfectly functioning control system. The loss of resolution is not significant in most cases. The procedure for scaling injectors/MAF has been discussed on here before and is covered in detail in my professional training materials.

RamAir
January 8th, 2013, 01:21 PM
Greg,

How will I know if the MAF is accurate to around the 70lb/min mass airflow value that I will need for the blower? Is the loss in resolution stemming from the scaling percentage employed to the MAF? If this is effective, why would most tuners still want to go to speed density?