Dialing in MAF Question

[SOMhaveit]

I think maybe I've missed something about tuning the MAF after AutoVE.

I did the AutoVE tune and got my VE numbers real close & then I plugged the MAF back in and logged the MAF with the PID's.

Did I need to change any of the settings for doing the SD Auto VE before I plugged the MAF back in? I ask this because I got the MAF where I thought it was dialed in and went back to closed loop operation and my LTFT's were as high as +10%. I went back and adjusted the MAF and VE in and got the LTFT's to drop down in some areas, but it doesn't run as good as it did in SD.

I followed the Auto VE tutorial to the T for the AutoVE.

[joecar]

Did you re-enable the MAF by setting the MAF fail frequency back to stock (i.e. be sure that it is not throwing DTC's P0101,2,3)...?

[SOMhaveit]

I did reenable the MAF by resetting the failure numbers to stock and I don't have any DTC's.

[joecar]

Does your IFR table match your injectors...?

[joecar]

When you dialed in the MAF table, did you first set B0120 to 400 RPM...?

Did you apply the throttle transient filter in the MAF BEN map...?

[SOMhaveit]

I have the oem 28.5 Bosch and the IFR table from the 2002 Z06. My setup is essentially a LS6/Z06 ported & cammed. So, the answer is that I have not performed any calcs on the IFR. The oem Z06 IFR is different than the OEM LS1 IFR. Does it match? IDK.

I did not change B0120 to 400, I left it at 4000.

I did use the throttle transient filter.

[BlackGMC]

When you dialed in the MAF table, did you first set B0120 to 400 RPM...?

Did you apply the throttle transient filter in the MAF BEN map...?

So you reenable the MAF, but leave STFT and LTFT disabled and set B0120 to 400 so that the only calculations are based off of the MAF and VE?

[SOMhaveit]

Does your IFR table match your injectors...?

The answer appears to be NO based upon a IFR calculator linked from one of your posts - if I inputted the right values. I inputted 42.5 Rated Fuel Pressure, 58 for Rail Pressure, and 28.5 for Rated Flow Rate & the numbers are larger than my numbers in my tune file.

[joecar]

The answer appears to be NO based upon a IFR calculator linked from one of your posts - if I inputted the right values. I inputted 42.5 Rated Fuel Pressure, 58 for Rail Pressure, and 28.5 for Rated Flow Rate & the numbers are larger than my numbers in my tune file.If you change the IFR, you would have to scale the VE table by the same percentage...

[SOMhaveit]

I have not messed with the IFR except to use the 2002 LS6/Z06 numbers before the AutoVE. However, the oem tunes don't have numbers anywhere near the numbers from the spreadsheet by redhardsupra.

This is the kind of stuff tht has me a bit confused.

[mr.prick]

from my experience, you should forget about getting your LTFTs
to be 0%/-5%.
i have set my VE table and MAF to 3 different commanded values
and each time my LTFTs would vary quite a bit.
now i am using the roadrunner and still LTFTs are not 0%/-5%.
there is just too many variables (alt,hum,temp,etc) for
OLSD to be perfect all the time,
therefore CL/CLSD will not ever be perfect.
i`m sure some will disagree , but this has been my experience.

[SOMhaveit]

I guess I'll try to find time to redo some of it.

[kevinc]

If you change the IFR, you would have to scale the VE table by the same percentage...

Can you explain this statement further? I upgraded to Ford/SVO red 30# injectors, input the new IFR table based on RedHardSupra's injectors.xls sheet (30 lb/hr rated flow at 39.15 psi rail pressure, 58 psi new rail pressure). Didn't touch my VE table which is still stock, and in SD mode my LTFTs are right where I left them w/ the stock injectors...+0.8 to -2.3%. Did I need to scale my VE table as well?

[joecar]

Can you explain this statement further? I upgraded to Ford/SVO red 30# injectors, input the new IFR table based on RedHardSupra's injectors.xls sheet (30 lb/hr rated flow at 39.15 psi rail pressure, 58 psi new rail pressure). Didn't touch my VE table which is still stock, and in SD mode my LTFTs are right where I left them w/ the stock injectors...+0.8 to -2.3%. Did I need to scale my VE table as well?Hi Kevin,

Welcome to the forum :cheers:

The context was this:
- the OP had corrected his VE table based on IFR table that did not match his injectors;
- he then wanted to edit the IFR table to correctly match his injectors, i.e. bump IFR up by some percentage;
- he would then have to bump up his VE table by the same percentage;
By doing this his VE table would now be correct (after correcting his IFR table).


In your case, your VE and IFR tables were both correct, and you changed injectors, so all you need to do is recalculate your IFR table to match your new injectors (leave the VE table as is).