How many of you guys are tuning with Narrow bands on Idle and light cruising

[Allen Vos]

Just curious how many of you guys are using the factory narrow bands to tune idle and light cruising with Short and Long term fuel trims Vs Using a Wideband in Lambda with EQ ratio?

To me the wideband seems like the better way to go for idle and light cruising as opposed to the narrow bands.

Is there a specific reason to use the narrow bands?

Obviously only a wideband can be used for Power Enrichment as the narrow bands cant.

[Ben Charles]

Unless you’re tuning full time OL, let’s the narrow bands do idle and part throttle

[RDF1]

Just curious how many of you guys are using the factory narrow bands to tune idle and light cruising with Short and Long term fuel trims Vs Using a Wideband in Lambda with EQ ratio?

To me the wideband seems like the better way to go for idle and light cruising as opposed to the narrow bands.

Is there a specific reason to use the narrow bands?

Obviously only a wideband can be used for Power Enrichment as the narrow bands cant.

Are you going to enable the narrow bands once your done tuning with wideband?

Ive tuned some with wideband then used narrow bands to confirm everything aligns with the info i got from the wideband.

[LS ROB]

+1 for fuel trims.

[edcmat-l1]

Unless you’re tuning full time OL, let’s the narrow bands do idle and part throttle

Werd.

[Cringer]

Since the ECM uses narrowbands to determine the fuel trims during closed loop, so should you. You are tuning to make the ECM happy, not the dubiously accurate wideband.

[edcmat-l1]

"The PCM doesn't care what your wideband thinks!"

[sgod1100]

NBs here for all of my CL tuning...then WB for OL/WOT stuff. I've never understood why guys tune fully with a WB for a CL tune....only to have the NBs come back in and start making corrections

[Allen Vos]

Fair enough guys. The masses have spoken.

Narrow bands it is. lol

It does make sense to tune with NB as the PCM will use that all the time for correction which I will leave on.


What is better, tuning with STFT only or STFT and LTFT?

Or does it really matter?

[hjtrbo]

Ltft carries over into open loop. 6 of one half of the other, I turn off ltft and just use stft.

[Allen Vos]

Ltft carries over into open loop. 6 of one half of the other, I turn off ltft and just use stft.

That is exactly what I wanted to hear.

I tried STFT + LTFT and had a tough time getting things set correctly.

As soon as I only did STFT I had good results.

Which is why I asked If it made sense to tune with a Wide Band.

Thank You

[LS ROB]

What I have found that works well for me is to use STFT + LTFT to get all the data. I then create a graph for LTFT ONLY and make corrections based on the LTFT's. This has helped me to sneak up on my fueling since I filter data then use the LT's, which is an average in itself, from what i understand. I was shocked to find out just how much more violence was left in the motor.

[Allen Vos]

What I have found that works well for me is to use STFT + LTFT to get all the data. I then create a graph for LTFT ONLY and make corrections based on the LTFT's. This has helped me to sneak up on my fueling since I filter data then use the LT's, which is an average in itself, from what i understand. I was shocked to find out just how much more violence was left in the motor.

So maybe STFT is better to help mold a basic tune, and adding LTFT puts the finishing touches on it then LTFT only really fine tunes it?

[JayRolla]

Ltft carries over into open loop. 6 of one half of the other, I turn off ltft and just use stft.

I know people say this but I have never actually seen it change my OL fueling. I have had 15% positive LTFT's and PE was exactly what I set it too.

[JayRolla]

So maybe STFT is better to help mold a basic tune, and adding LTFT puts the finishing touches on it then LTFT only really fine tunes it?

I have done it both ways. I have found just using STFT is a bit quicker to get a clean VVE table. I also have not seen the postivie LTFT actually change PE in OL like many say it does. But to be sure most using LTFT just make sure trims are negative 0-5% since only positive fuel trims pull over to OL.

[04silverado6.0]

I normally tune in ol with wideband, set to stft only when done. I dont need ltft when my fuel trims are +/- 2. I do tune closed loop, stft only, with wideband for the wot stuff on email tunes. Makes it safer for the inexperienced eyes and right foot on the other end. If im getting results using my ballenger and aem widebands why change it up?

[Cringer]

I just turn LTFT off and keep them off. If you are ever "done" with tuning then turn them on. But the hard part of tuning, logging, revising the tune, driving, logging, etc is that you need to reset the LTFT learned values in the scanner before you drive and log each time (at least if you are making air/fuel changes). This is easy to forget and adds extra time and steps to the tuning process. And if you forget, then the potential for error starts to creep in your tune which will delay final results and have you going in circles.

The other argument is that the last LTFT value that is active will be carried forward into PE fueling. I have seen this happen on my E38. Which then throws off your attempts to calibrate PE air/fuel.

[Alvin]

The other argument is that the last LTFT value that is active will be carried forward into PE fueling. I have seen this happen on my E38. Which then throws off your attempts to calibrate PE air/fuel.

Only the positives do.

GM has been doing the same since the chip car days.

[Cringer]

Only the positives do.

GM has been doing the same since the chip car days.

Thanks for the clarification!

[Ben Charles]

LTFTs off or keep the fuel trims little negative and keep them on