beginner guide to ve tuning with STFT, HELP!!!

[hafs99]

Hi all,

I recently purchased HP tuners and am starting to tune my truck. I have a 2000 5.3 silverado and have done the basic things like turning off COT and Torque management. Im looking for an updated guide to VE tuning without a wideband since my current budget as a college student is very limited. I found Cpigs guide but have seen posts saying it is out of date. Does anyone have a document that goes step by step on how to do basic tuning without a wideband, or can someone help guide me along the way. I understand the basics of how to find find where my LTFT and STFT are by disabling the MAF and going into SD and making the low octane table the same as the high octane. I had reset by LFTF earlier this week and drove over a hundred miles and my LTFT are all between 8 and 0 on both banks. My SFTF are between 4 and -4, and i have data logged from 0 to 4000 rpm. I am now stuck though because i dont know which route to take when tuning with the STFT alone.

My tuck has a CAI and full straight pipe, no cats.

[tbrtuning]

Don't worry about STFT by themselves. Just add then to LTFT. Long term is a learned value updated by the short terms over time. So long term is the starting point and short term is applied on top of that. You can add the two together to get the complete correction at the time

[hafs99]

So i should just coppy the LTFT and STFT tables out of the scanner and do past special add in the VE primary and secondary table?

What was the reason then for people saying to disable PE and LTFT and then enable MAF and pulse the petal from 0-100% TP for each rpm cell

[tbrtuning]

You can do it that way. When you get into PE you lose your fuel trims being accurate. If you just want to tune for where you are in closed loop and blend out the changes you're fine without doing that.

If you want to tune WOT to be as accurate as possible without a wideband then keeping it out of PE is the way to go though. Pull some timing out to keep it safe if you're going to do that though.

[hafs99]

Alright so ill copy and past my tables for LTFT and STFT into my VE tables. Do i need to tune for WOT then, or can i just leave the rest as is until i get a wideband? I should then be able to re-enable my MAF then too correct?

[tbrtuning]

You're getting into something kind of questionable there honestly...

Use a new graph with the math LTFT+STFT and paste multiply not add for one thing.

If you do not tune for PE filter out data where it's commanding richer than stoich for one thing. I also would try to continue trends you see further down the table. Example being if 4k RPM and 60 kPa is the highest you have data and you're pretty consistently having LTFT+STFT adding 5% more fuel up to 60 kPa at 4k go ahead and add 5% (or a little more to be safe) to higher airflow at 4k also. If you see more and more needing adding at higher loads continue that pattern the best you can out to where you don't have data.

[1364838952]

I agree with Riden.. The maths graph will be your best bet if using narrow band O2's for now. Please be certain that after you paste % by half into your VE table that you look at a 3d Graph of what your new table looks like and smooth any mountain tops, or spikes, and also any dips (lean spots). Do not just expect that you can paste, burn, and be done. You will need to smooth the table to avoid any large jumps from one cell to the next to make a smooth transition in fueling.

This video may be of help; https://www.youtube.com/watch?v=R5lp...D_8mwtqj1G5teT

[tbrtuning]

Good call mentioning it being smooth. I forget that most new tuners just copy and paste.

[anniversaryss]

Use the Math paramter stft+ltft and log the axis against what your VE says

[bk2life]

log the axis against what your VE says

what does this mean? or, more importantly, how do you set this up in he scanner?

[blindsquirrel]

what does this mean? or, more importantly, how do you set this up in he scanner?

screenshot.15-03-2023 18.27.18.png screenshot.15-03-2023 18.27.37.png

screenshot.15-03-2023 18.28.11.png

That's my VE table... yours will be different. Make the graph match the column & row axis labels in your VE table. Simple copy/paste.

[bk2life]

Make the graph match the column & row axis labels in your VE table..

thank you. i figured as much, but, wanted to carlify for the next person that comes along this post like i did.

[phuz]

Why, when pasting in the LTFT + STFT values, are we doing a multiply by half? Is that so that we're doing this in baby steps and not being too aggressive?

[TheMechanic]

Why, when pasting in the LTFT + STFT values, are we doing a multiply by half? Is that so that we're doing this in baby steps and not being too aggressive?

Yes. Baby steps. Keeps you constantly, incrementally, towards a zero instead of an overshoot back and forth.