Kennyspec

So the stock MAP sensor maxes out around 215kpa ~ 16psi so what is controling the fueling process above 215kpa??? The VE table is maxed out at 215kpa so its it just the MAF HZ that you tune to control fuel???

stotte20

holy **** i have no clue what you are saying. but im interested to learn or is this canadian psi??

Acidangel_5.0

kappa.. canadian psi

he is talking about fuel maps for boosting over 16 psi

foff667

are you running SD all the time ie no maf?

EvlPeanut

Kappa?? kpa is an abbreviation of kilopascal... a Kilopascal is unit of measurement for pressure in the International System of Units, not just a Canadian thing.

Kennyspec

ni am not but if i was what would happen???? it would just use the value in the 215kpa column in the VE table even though its over 215kpa right?????

and when not in SD mode it would use the value in the 215kpa column and rely on the MAF for all other fueling calculations????

c24na

good question...haven't gotten that far yet.

listening.

Nate

Kennyspec

im sure foff667 will have a answer for us.........he seems to be full of usefull knowledge

Witt

MAF is the primary means of air metering. Your MAP sensor is 2.5 bar, your table is 2 bar. When you go out of range on the VE table, it just uses the last known good value which would be the 215kpa column.

This is correct, its relying on the MAF all the time. MAP is just used to check for MAF failure and to calculate an air model to check for electronic throttle control failure, unless you force it into SD.

zinner

I think that some people have experimented with an LT1 MAF with some success. This will allow you to not go above the HZ limits of the MAF table.

06blackg85ss

iTrader: (1)

I think the sensor it good to over that, but the tables in the stock PCM don't read it... Goes by PE table after that.

foff667

The reason I asked was kinda to make a point...when you not in SD the maf does most of the work rather then the VE table the maf isnt just there to sit around looking pretty.

So the life after 215 has very little bearing in the overall fueling for the most part unless your running SD all the time.

When the maf is in play you can use the maf/pe tables to do most of your fueling adjustments.

Witt

You'll have to do some SD tuning if you plug 60lb injectors in there, or you'll be in limp mode pretty quick. But running SD is mainly a waste of time because of the 2 bar limit on the software.

RaineMan

what about all the guys running a 2.9" pulley? Isn't that over 16psi?

06blackg85ss

iTrader: (1)

I"m running 60lb injectors and the car runs fine... just added @3% to the Ve table and no problems..

Witt

Yes, however, they are also using a mass airflow sensor. This is only a problem if for some reason you would want to run in speed density. I imagine the turbo swap/twincharge guys would have a fun time dealing with this if they removed their MAF.

Because of the IFR table going out of range down low in vacuum, the VE needs to be changed to reflect that. You still have a MAF so its not affecting fueling, but you might be close on what the PCM considers failure for the P0068 MAP-MAF correlation test. You can disable this through the Engine Diagnostic tab, but you'll lose cruise control because the PCM doesn't know if the ETC is working correctly.

Kennyspec

i thought that you "set" the PE table to what AF ratio you want. ex. 14.7/12.0= 1.225

so if i want a 12.0 AF ratio all the way up to 7000rpm i would just set all the values in the PE table to 1.225??? How do i use the PE table to adjust fuel when my MAP is maxed at 215kpa??

wouldnt i just log the % error in the MAF histogram comapring my commanded afr to actual???? and use the MAF to control my AF ratio and not worry that the map is maxed out at 215???

Witt

1) Yes, that is correct, assuming you removed all other sources of enrichment such as piston protection and cat over temp enrichment.

2) The PE table is based on RPM, not map, the 215 kpa value doesn't affect it.

3) Yes, also correct.