Whipple Install, now Split LTFT, and Lean Split at WOT

[10_SS]

Yea my Lm1 was a pile if junk I thought anyway and the analog output signal is better on the NGK, but anything that I have no way of verifying makes me nervous. Anybody want to buy an LM1? I have one for sale

[DSteck]

How do you expect to verify any wideband?

I use three separate NGK AFX widebands. I just broke into the four digit power level on my Z06 "trusting" one of my AFX widebands.

[10_SS]

I don't think you can, really just curious if there was a way to put the AFX to hold say 11.0, and verify hptuners showed the same reading... But I read the display value is 0.1-0.2afr off of stoich.. So curious what the two should read at 11.0. Guess it doesn't really matter as long as the values don't drift right? I tune till the motor is happiest.

I was able to start my old car then shut it off and the AFR would kinda hold the rich value (~11afr) long enough to check the display vs. the logging software, and tweak the formula accordingly so they match... Wondering if people bother to check that with the AFX/hptuners combo?

I wonder this since the MAF calibration is so heavily dependant on this wideband signal.

[DSteck]

Wow. You really shouldn't put that much "thought" into it.

[Area47]

you're making this way more complicated than it really needs to be.

[HRD]

I just broke into the four digit power level on my Z06 "trusting" one of my AFX widebands.

Not to get off subject, but are you able to hook that much power on the street?

[DSteck]

Not to get off subject, but are you able to hook that much power on the street?

I've only driven it on the 935whp/881ft-lbs setting. Has to be in third on DRs to bite, although now its too cool out to hook up.

[10_SS]

I've only driven it on the 935whp/881ft-lbs setting. Has to be in third on DRs to bite, although now its too cool out to hook up.

Is that in the Vette? I drove a Vette with a stovk LS3 and it was so much lighter than the camaro the difference was insane!

[10_SS]

Wanting to know if the AFR calibration is right in HP Tuners on a brand new setup is overthinking? That's an interesting way to look at it.

The picture shows Stoich (14.67) AFR readings using DSTeck's recommended cal info which on my setup is close showing an average of 14.5AFR, this is with -1% MAF vs. WB AFR error, and -4.7 LTFT error.

The PCM is targeting 14.67 and very steady at what it's holding, so it seems I would want to make the WB AFR in HP Tuners match the PCM's commanded AFR which we can only assume is properly running at 14.67.. so at least Stoich would be stoich in the PCM, in HPTuners, and the wideband outputting into HP tuners. If don't make these match, every time I adjust the MAF using the MAF Error histogram, I will create LTFT's that continue to grow away from 0%.

Right now there is 0.2AFR error in the wideband according to HP Tuners Stoich, so if I simply shift the offset up by 0.2AFR to make 14.5 = 14.67, then this would fix any tuning problems, and worse case sure a real 11.1AFR would = 11.3AFR, or it could possibly tighten up the error at that AFR.

If anybody knows if the PCM actually create's an average of 14.5afr when it's commanding 14.67AFR, then this would be the only reason I wouldn't want to adjust the reading.

[DSteck]

Jesus. The PCM biases towards slightly rich in closed loop. Stop mucking with trying to adjust the transfer function.

[10_SS]

I meant how do I know HP Tuners is displaying the correct signal from the WB..

All you have to do is log data from the AFX while it's unplugged, then turn it on. As it warms up it will go to 1.0 Lambda like you said, but also I found next it goes low (0.62 Lambda) right after.

Quick and easy test that I was looking for, helped me calibrate and VERIFY my HPtuners readings were correct, everybody should do this since they will see how far off or how close there HPTuners calculations really are.

This formula gives me 9.10AFR low, and 14.68AFR at 1 lambda: 0.6992 (14.68) + 9.095 (9.10). If I messed that part up no big deal as now I can change the formula to compensate, easily!

I never run calculated anything when it comes to sensors since calculations are never perfect. Fine tuning is always required.

[DSteck]

If the proper function doesn't give accurate readings, then you have a power and ground issue. Changing the function to suit one data point is just bad practice. How do you know an adjustment to the linear multiplier isn't needed?

People should really stop this whole voltage offset crap. I don't understand why everybody thinks that's the right approach.

[10_SS]

Yes there very well might be grounding differences between cars as there always will be, especially between platforms. Calculating is fine to get you close but I've always had to verify and adjust to get it perfect.

Same is true for the MAF. Every car is different.

EDIT: BTW, I have the AFX wired direct to the battery, with a relay turning it on/off. It's the perfect setup as far as ground issues go.

Also, this way, at any time I can check at startup log that my HPtuners shows 14.68 then 9.10, if it doesn't show those two numbers exactly, then I know something is drifting.

It's a linear output, so 9.10-14.68 should be right in line. Now, even if I kept the 14.68 reading 14.60 or even 14.58, would that change anything else? Not really, but at least this way it's as accurate as it can possibly be, and it only took less than 5 minutes to do so not a big deal.

[DSteck]

[Area47]

Ds. you're forehead is rather bloody from slamming it in to the desk. take a break.


those who are over the edge on analytical discrepancy can cause more harm than good.