AutoVE MAF calibration clarification needed

[Redline Motorsports]

Just completed at AVE tune on an 04' GTO that we did a 377 Procharged motor in. All went well thus far and have all the cells dialed in at 0 to -4 % all the way to 4500 rpms and just about 85-90 KPA. I am not going to go any further as the car gets way to hot under load that long. I would think the area that I tuned is the overall area of cruise and idle and anything much out of that is getting into PE mode.

I want to leave the car in OL so I am not going to go back and reenable CL. Next step would be to reenable the MAF and make a map to log htz. vs BEN. My question is; do I go back to the PE/RPM and reload my desired AFR at WOT (currently at 14.63) to the desired AFR and then run the car through the different cruise cells and cut and paste........what do you do with WOT fueling and the MAF???

I am confusing myself on who comes first.

Howard

[SSpdDmon]

How much boost are you running? You'll have to becareful with altering the MAF on a forced induction car as you may max out the MAF due to the 512 grams/sec limit in the PCM. That's why people either go with a SD tune or end up altering the injector flow tables and PE tables to get the desired AFR. If you end up playing with the injector and PE tables, it could alter all the work you've done in SD. If you stopped tuning at 80kPa, the first four cells (0-20) or so of the IFR table shouldn't affect your SD tune since they are referenced to manifold vacuum. In other words, atmospheric pressure minus manifold pressure (MAP) equals manifold vacuum. Typically, atmospheric pressure is close to 100kPa depending upon your elevation.

[Dirk Diggler]

if this car is seeing more that 8lbs of boost i would leave the maf alone you will max it out around 8 psi and if you are hell bent n using it switch to the 85mm as they take a little more before the top out

[Redline Motorsports]

I already tuned the car three months ago, and 4000 miles later, and it runs great. I am only trying to clean up the cruise fueling at the TRIMS have been close to 20 % positive. The car has made 602 RWHP and 540 RWFT on 7.5 PSI no problem.

I just want to know how to finalize a VE tune after the VE table is completed. When you make a map for the htz. vs BEN what do you use as the heading on the column side?

Also what comes first; set the PE to the commanded and then make a cycle to log the BEN?

[Dirk Diggler]

I just use rpm and set it to 8000 or value.

[Redline Motorsports]

OK,

what about the order of steps aftert he base VE is done?

[Dirk Diggler]

I assume you are using COS3 i would continue using the RPM vs MAP vs AFR table

[Redline Motorsports]

Actually I am still on the stock os!;)

[Dirk Diggler]

Use PE vs RMP and leave the Commanded OLFA table like you set for VE stuff. Personally I dont seethe point int diabling PE I like to tune the car the way it will be driven and CAREFULLY dialing it in slowly bringing it up through the range but thats me

[Redline Motorsports]

Ok how about this;

I did a htz. vs. BEN map. Once you get towards 6000 hrtz. you are just about in the range that PE is starting. How far do you log into before you need to adjust the PE x RPM table. I guess if I command a AFR of 11.8 at 4700 rpms and up then when I log the htz/BEN that whatever the MAF needs to be calibrated to to get the 11.8 is what gets changed in the MAF cal. The MAF is still the last determiner over the VE...correct?

I know what I am trying to say but don't know if I am saying it right!:bash:

This is just mearly to clarify my thoughts.

[joecar]

Howard,

Good questions mate.

If the VE table is correct, then just set the PE to whatever you want
(what you set is what you will see on the WBO2, because the VE is dialed in);
if you have a dyno, you can see what PE curve gives the best TQ and HP.

Then make the MAF agree with the airflow that your VE says.

Yes, that's correct, adjust the MAF so the wideband AFR matches the commanded AFR
(your efforts are to maintain this match).

MAF is used above 4000 RPM, combination MAF/VE is used below 4000 RPM.

Cheers
Joe

[SSpdDmon]

I would adjust part throttle so that you eliminate the possibility of positive long term fuel trims. You can actually increase the upper end of the curve by about 16% before you hit the 512 grams/sec mark. So, I'd adjust the lower end of the curve until you hit that 16% increase over stock and continue it as a constant to the top. Then, go with the PE adjustment from there. Hopefully, you don't need a 16% increase before ~6000Hz where your PE is starting to kick in. The other option could be to adjust where your PE comes on based on TPS% {B3616}.

[Redline Motorsports]

I guess in hine sight I could have globally multiplied the MAF table by 15% then. This would have added 15 % of fuel to the entire VE range.

When I checked the LTRIM history all cells where the same amount of positive error. I already got the VE on the money and did a light pull with the MAF enabled up to about 6000 htz. My question again is that should I set the PE/RPM back to the values I originally had (which where kind of off from the real AFR) or should I just set it to what I want, make a hard pull and let the error be cleaned up with the MAF table?

Howard

[TAQuickness]

Just hitting the basics for clarification

VE table = air flow table
MAF Cal = air flow table
{B3605} = Fuel table
PE = Fuel table

The PCM does not measure airflow - ever. The PCM relies on sensor values (MAP, RPM, MAF, etc...) and then looks up air flow in a table. *Air flow is a generic term I'm using for various air values used by the PCM*

{B3605} represents the base fueling. At any given ECT & MAP, the PCM will look up an EQ ratio.

Final commanded AFR = {B3601} / EQ Ratio

PE is a conditional fuel table with several tables effecting when it becomes de/active and how fast it becomes de/active.

The PCM will use the PE table only if the EQ values in the PE table are greater than the values in {B3605}. In other words, the PCM uses the richer of the two values.

With PE disabled:
In OLSD, at any given engine condition (except startup), the PCM will look up the respective EQ ratio, respective air flow, and calculate an injector pulse.

In OLMAF, at any given engine condition (except startup), the PCM will look up the respective EQ ratio, respective air flow (under 4000 RPM = blend of VE table and MAF table, over 4000 RPM = MAF table), and calculate an injector pulse.

When PE is enabled, the fueling becomes a variable, hence disabling PE in the AutoVE tutorial (KISS). Having PE enabled on a stock OS makes sense because {B3605} is based on ECT & MAP. However, OS3 and OS5 utilize {B3647} in place of {B3605} and allow us to command fuel for any RPM & MAP. The higher resolution of {B3647} allows you eliminate the use of the PE table, thus eliminating the transient data produced by PE transitions.

Hope this helps.