tuning vehicle not using any wideband

[SSpdDmon]

so then you are pretty much telling me that if I do not have a wideband to do auto Ve then this won't work..

if so that is BS.

you might might not be understanding what I am tryign to say.

I just wanna take my car to the dyno put the sniffer on the tail pipe and change parameters.

IE fuel and timing.

Now the question is wich one do I use Backup or Main. and is there any other for fuel.


I mean Auto Ve is like auto tune right. When I tune my EMs on my 4 banger i just tune it with dyno wideband and that is it.

do you guys understand now ?

thanks,

Ed

I get what you're trying to say. What we're trying to say is the AutoVE is an in-depth procedure that most tuners don't go through the trouble of doing. If you're just interested in dialing in your AFR and timing on the dyno, that is entirely possible. Tweak the timing and play with PE until you get the desired results. However, take note of your fuel trims prior to hopping on the dyno because they will most likely be reset after you flash in a tune. This is important because if they are positive (say 6%) and you dial in the AFR after flashing it a few times when they're at 0%, they're going to go right back to 6% after some driving and they'll carry over to WOT making you 6% too rich.

The 'old school' way of doing things is to notice where the fuel trims are at, make some adjustments to the Inj. Flow Rate table to get them close to zero, and dial in WOT with the PE table. That can be done before and on the dyno using the ltfts and a WB. That's the quick way to get it done....no touching VE unless it's cam'd and you need to pull fuel so it'll idle.

[dsmlights]

understood thanks for the info guys i am finally getting this. now I should adjust PE modified based on rpm correct?...

Well isen't PE adjusted by NB02 feedback? can someone explain to me how PE actually works.

So then adjusting the VE Main table is a nono for WOT tuning.


Man guys I am sorry I am asking so much, but i am just geting confused with all the diff tuning stuff there is .

anymore info you guys have will be great.

thanks,

Ed

[dsmlights]

there are so many PE table wich one should I use PE based on rpm ?

thanks,

Ed

[SSpdDmon]

PE vs. RPM is used.

PE is a part of open loop. In open loop (i.e. when the NBO2 sensors are ignored), the PCM reviews several tables like PE, Commanded Fuel in Open Loop, Catalytic Converter Protection, etc. Under the current conditions reported by the different sensors (ECT, MAP, etc.), it looks up all commanded AFRs and correction factors that apply. It then takes the richest value of the bunch and bases it's perceived fueling requirements based of that value.

The only time the O2 sensors have anything to do with WOT or open loop is when during closed loop, the PCM learned that fueling was off and it introduced positive long term fuel trims. Those fuel trims will then carry over to WOT. Negative fuel trims do not carry over. When tuning, you should always be targeting LTFT=0% when in closed loop.

See post #5.

[dsmlights]

so since my car is pretty much stock my ltft should ne around 0 right ?? then I should just change my PE to about 12.6 or so and I should be good right. Also what will happen if I change

VE Main table?? can I do that or is that not a good thing to do.

[ScarabEpic22]

Stock LTFTs are probably not 0, GM tunes these to be on the safe side with a conservative calibration that will work for every engine they make. Tuners like us go in and tweak the cal so we can get the most performance out of our specific engine, and therefore LTFTs will probably need to be adjusted a little.

[dsmlights]

but as for right now since i am pretty much stock and I am trying to lean out to make a few more whp. then I could just adjust my pe to 12.5 and be done with it for now. right.

[Doc]

So then adjusting the VE Main table is a nono for WOT tuning.

Actually, it's a emphatic yes! Not to be confusing but, all I was trying to say was unless you have more mods and plan on investing the time-researching here and all over the net and, acquire a V1/V2 and a WB02 you are going to get the most overall satisfaction with your dyno session by adjusting PE vs. RPM and timing.

Man guys I am sorry I am asking so much, but i am just geting confused with all the diff tuning stuff there is .

There is no limit to the information you can dig up on this forum from it's members and the massive amount of published information contained herein.

The only thing "we" collectively ask is for you to immerse yourself in it and ask pointed questions- as you now are begining to do. Most members will not spoon feed questions like "So I want to go fast and get hot chicks..."

anymore info you guys have will be great.

Ok, chew on this....

http://carprogrammer.com/Z28/PCM/LS1/Holden_LS1.pdf

[TAQuickness]

If you are looking to tune WOT only, and the goal is simply to lean out a tad for more RWHP, then the PE table is what you're after.

If you intend to make adjustments to any of the air flow tables:
OLSD = backup VE table - then transfer to MainVE for MAF operation
OLMAF = MAF table