BlownAlaskan

iTrader: (3)

When I go WOT, my afr seems stuck between 10 and 10.5:1. I've ran my pe/rpm table almost to 0 with seemingly no change. My trims are neg at idle and go zero like they should at WOT. My IFR is .7027 across the board, and my maf and ve tables are stock. COT has also been disabled. Any ideas?

MeentSS02

iTrader: (11)

Doesn't the VE table have some control over WOT? You might look in there...from the best of my knowledge, the PE table only deals with the fueling part. The VE table is the airflow portion...

txhorns281

iTrader: (12)

Your IFR is what now??? If it's .7027 for the whole table that's definitely not right. Essentially it's telling the PCM that the injectors are smaller then they are, which is holding them open longer (pulse width) and with your 57#ers, that's probably pushing the motor extra rich. Also, what unit are you using? That may make a difference...

And the MAF (if plugged in) will be what determines A/F production vs. commanded AFR. Otherwise in SD mode, the VE controls the airflow input.

jimmyblue

iTrader: (11)

First off check the commanded AFR (I prefer to view
the Fuel Air Multplier PID) against the actual measured
by wideband. This will tell you whether it's a problem
of calibration or command.

If you're getting what you asked for then you have to
look at the PE vs RPM and the Open Loop Fuel Air and
make sure COT (cat overtemp protection) is off, that
you aren't throwing excess fuel from the adders like
ECT etc.

If you are getting something that's more than a couple
percent off from commanded then it's airflow (probably
MAF above 4000RPM) or fuel (IFR table, excess fuel rail
pressure, etc.) calibration.

BlownAlaskan

iTrader: (3)

Injectors are siemens 57's from racetronix, I had to reduce the IFR to .7027 to get negative trims. Jimmy, I will pull up the commanded afr pid and see where it is at. I couldn't find the air/fuel multiplier in flashscan. What exactly is commanded AFR? Sorry guys, I'm a newb.

jimmyblue

iTrader: (11)

Commanded air-fuel ratio is what the PCM intends.
But the thing actually works on the basis of fuel
air multiplier (FAM), this is the 1.xxx value you see
in the PE, OLFA, COT tables etc. FAM = 14.7/AFR
(commanded).

57 is a big injector and the flow I would think should
go up to model them. I don't like using IFR to tune
the trims -except- if you had proper trims pre-swap
and are trying to get back to a known good cal. The
flow (and offset) should fit the fuel system and not
try to fix airflow calibration too (that's too much to
ask of one little table, after all).

BlownAlaskan

iTrader: (3)

The commanded afr (gm.afr) pretty much stayed locked at 14.68 and didn't seem to change at all while driving, it flucuated a little at idle. Im not sure I have the right pid? Regardless, my wideband showed consistantly richer than the commanded. Should I try to raise my ifr back up and adjust something else? I've never messed with any of the other tables other than IFR and PE/RPM. Continued thanks.

BlownAlaskan

iTrader: (3)

Forgot to mention, I was looking at the other units for my IFR, in gms/sec my IFR is 5.313

jimmyblue

iTrader: (11)

Commanded AFR will be 14.7 except at WOT (PE) and
maybe deceleration. It's the WOT bits you want to
focus on. The rest is closed loop and you don't care
(for purposes of this exercise).

BlownAlaskan

iTrader: (3)

Jimmy, just did a quick log and the commanded afr just sits at 14.68 including wot.??? Do I need to use a different PID?

BlownAlaskan

iTrader: (3)

First, I am runing a good bit richer than commanded AFR. When the commanded is 13.8 I am around 12.0.

I've tried slowly increasing the IFR to around 6.8, which brought my part throttle and WOT AFR closer to where they should be, but my L trims at idle are around +20. What should I adjust to get the trims back in line for idle?

txhorns281

iTrader: (12)

Once you get your IFR table correct, then you can move on to MAF/VE changes, this will take care of your trims and the resst of your fueling (if done correctly... )

BlownAlaskan

iTrader: (3)

txhorns281: What is the best way to get the IFR correct, I only have the IFR's that 3 people who had these same injectors gave me to go off of? Sorry guys, Im a total beginner!

txhorns281

iTrader: (12)

We know the IFR table for your stock 26.4 #ers right?

Ok so you need to make sure that you convert the flow rate to the same psi rating before we can do any scaling.

You take the sq root of: Desired PSI (58)/Current PSI (whatever psi your new injectors are rated at) and the multiply that by the flow rate (57 lb/hr)

This will get you the new lb/hr flow rate of your 57#ers on the LS1 fuel rail. Now take this # and divide it by 26.4 and that will get you your multiplier to scale you IFR values with.

And this should not matter if the units are in lb/hr or g/s, it's just a scalar unit that can be applied to the whole table.

BlownAlaskan

iTrader: (3)

txhorns281:Okay, let me see if I have this right: SQR(58/43.5) * 57 = 65.8179, then 65.8179/26.4 = 2.4931. Then 2.4931*2.7422(stock99IFR) = 6.8366.

Next question, how do I adjust the trims and then WOT from here? Continued thanks.

txhorns281

iTrader: (12)

Now you can do all the VE tuning junk that is highlighted on one out of every two threads on here... read up and ask later when you get stumped.