Hi, I am using TunerPRO RT, and tweaking my MAF tables for $1F bin, using a 1F.XDF, for a 85 870ecu L98.

I am lean and am bumping up the air flow values in the MAF tables 1-6 to force richer fueling at those count values.

For those familiar with this, you know that the valid values for the tables are based on a different scalar for each table, and that the highest stock value in each table is very close to the max value dictated by the scalar. I read about changing the scalars by editing the parameter XDF info tab, under the conversion tab, for the global table equation.

For example the T1 conversion value is 0.089844. Which is 23/256. So 23 is the T1 table scalar. I used a new scalar of 25, which comes to 25/256 = 0.09765625, and changed the T1 global table equation. I bumped up the scalar for each T1-T5(T6 is always 1) by 2-4 so that I could increase the max values evenly across the tables, making sure to match the end of the prev table to the beginning of the next. My change was moderate about 10% increase, just to test how much richer the increased values would affect the AFR on my wideband.

This didn't work. The AFR became so lean that the car would barely run. It was like the ecu had its scalar conversion hard coded and my change to the XDF conversions just calculated values that were too low when used for the AFR calcs causing too lean results.

For those who are familiar with this, did I misinterpret the way to change the XDF conversion values to allow higher max values on each table?

Thanks