GuitsBoy

iTrader: (4)

Is there any way to log VE correction? Also, are there VE correction cells similar to FTC's?

When I tuned my VE table, I set the VE correction uppper and lower limits to 1.001 and .999 respectively to essentially take VE correction out of the equation. I then re-enabled my MAF and got my fueling inline with the MAF enabled. Now I decided to set the VE correction limits back to stock, and all of a sudden my fueling is completely jacked up. Im hitting AFRs of 18:1 at idle. How can I log VE correction to try and square things up?

Bill Bowling

iTrader: (6)

What software are you using?

Bill

GuitsBoy

iTrader: (4)

HPTuners, of course

Jpr5690

iTrader: (13)

Cant You Do Lift Tuneing Of Your Ve (with A Disabled Maf)

GuitsBoy

iTrader: (4)

Whats "Lift" tuning??? Never heard of that.

Anyway, the VE table was tuned in SD (MAF Unplugged) with the correction factor effectively disabled (set limits close to 1). I then tuned it using the MAF and got that in line. Then when I set the VE correction limits back to stock, the tune went out of whack.

Jpr5690

iTrader: (13)

Basically You Unplug The Maf And Log Your Long Term Fuel Trims Then Apply Your Lifts Against Your Ve Table ....(this May Be What Your Already Doing)

GuitsBoy

iTrader: (4)

No LTFTs. im running open loop. Im logging via wideband.

But now that I understand what youre saying, yes, im quite familiar with the process. Although may I suggest this to you for future: I find its easier to set your LTFTs to 0 and lock them, then just log STFT averages. Much quicker process, and better resolution, since youre not locked into FTCs.

VE correction is somthing a little more advanced than basic VE table tuning. The correction factor is a multiplier thats used by the ECU to get dynamic airflow and your maf readings to match. Lets say your MAF is telling you that your flowing 2.5 g/sec, but your dynamic airflow reads 2.0 g/sec (based off of VE and rpm). The computer would [supposedly] adopt a VE correction of 1.25. Heres an equation: [Dyn Air] x [VE correction] = [MAF].

My question is that if the VE and the MAF tables were dialed in, why would the VE corection stray so far from 1.000 once it was re-enabled?

Jpr5690

iTrader: (13)

In Theory If Your Ve Is Tuned And Your Maf Is Tuned Shouldent You Have A Correction Factor Of 1?

And If Not Dosent It Just Mean Your Ve Dosnt Match Your Maf (so Just Retune One To Match The Other)

GuitsBoy

iTrader: (4)

Yes, In theory it should.

Apparently thats not the case. The two matched when the correction factor was locked at 1. When I removed the constraints and it the correction factor was now able to move freely between 0.5 and 1.5, the MAF and VE no longer match.

I disabled the MAF again to check my speed density tune, and so far everything seems normal in SD world.

Jpr5690

iTrader: (13)

Well Lets Sit Back And See Whos Got The Answer....(i Sure As Hell Dont)