Improvements!

[12secSS]

I think I am very close to my 2001 Camaro SS being optimized as much as possible in the LTFTs. My wife and I have notice that the car responds a lot better than before ... even our mechanic friend that test drove it noticed "it runs a heck of a lot better".I think I will start tuning the STFT now. Below is my progress of my tuning, I have the LTFT & STFT of the OE tune vs my current results. The car only has Hooker LTs & ORY as the major A/F mod, as well as Throttle Body Bypass and Ported/Polished Throttle Body. State your opinion if so desired.

OE STFT average results


Tuning STFT average results


OE LTFT average results


Tuning LTFT average results

[Dixit]

Wow thats a pretty horrible looking LTFT table before and well done after.

Side question, how do you tune the STFTs? Ive just been tuning the LTFTs. Never heard anything or how to tune the STFTs

Dixit

[12secSS]

Thanks, that is what encouraged me to tune my SS. And to believe that at one point I tried using ATAP and a MAFT to tune that! LOL

To tune you STFT you simply disable the LTFT learning process, either by setting the learning process to off or setting the learning ECT value very high (250 degrees). Then the VCM will not use the LTFT values to adjust your A/F and you can directly add/subtract the STFT values from the VE table. If they are negative, you add that value ... if they are positive you subtract that value. Simple!

[luv2spd]

Um, if you have postive trims, you add to the ve table, not subtract. Positive trims equals too lean. Add to the ve to add fuel.

[12secSS]

The VE table is the Volumetric Efficiency table, how well the engine can breath. If I add more to a cell that has a lean (positive) value, it will go further lean. You want to richen it up. Vice versa for negative cells, those are running rich and you need to lean them out. This table is used to calculate the fueling requirements for each Kpa/rpm cell.

typo fixed: positive was negative

[Dirk_Diggler]

The VE table is the Volumetric Efficiency table, how well the engine can breath. If I add more to a cell that has a lean (negative) value, it will go further lean. You want to richen it up. Vice versa for negative cells, those are running rich and you need to lean them out. This table is used to calculate the fueling requirements for each Kpa/rpm cell.

Lets pick apart what you have typed here which by the is blatanly wrong


Yes the ve table is a Volumetric efficiency table ranging from 0-100 (0 beign less efficient 100 being most efficient). Your LTFT is a DIRECT representation of fueling. + numbers mean fuel was added and - numbers mean fuel was subtracted (cant get no simpler than that). If fuel was added then you were running lean and the opposite is true for fuel being subtracted. So taking your histogram where you have +4 the PCM is tellnig you that it has to ADD +4% of fuel to acheive the 14.7:1 AFR. If you wanted to correct this guess what you would have to do. ADD 4% to teh ve table at that map and RPM. If you subtract fuel you will be further in the hole and the next time you log you will be +8.

If you dotn beleive me or anyone else here you can do this for a test its only 27 seconds. Find a negative cell and apply you theory to it. Move in that direction by 10-20% and see what happens. I bet you'll come back and edit the post.....

I can also tell that you arent doing this by hand but are doing this with the copy paste feature. If this is the case look at a previous tune and then look at the one you just made and you will see with your own eyes that -LTFT cells get fuel taken away (lower ve values) and + LTFT cells get fuel added (higher ve values)

[WS6snake-eater]

Lets pick apart what you have typed here which by the is blatanly wrong


Yes the ve table is a Volumetric efficiency table ranging from 0-100 (0 beign less efficient 100 being most efficient). Your LTFT is a DIRECT representation of fueling. + numbers mean fuel was added and - numbers mean fuel was subtracted (cant get no simpler than that). If fuel was added then you were running lean and the opposite is true for fuel being subtracted. So taking your histogram where you have +4 the PCM is tellnig you that it has to ADD +4% of fuel to acheive the 14.7:1 AFR. If you wanted to correct this guess what you would have to do. ADD 4% to teh ve table at that map and RPM. If you subtract fuel you will be further in the hole and the next time you log you will be +8.

If you dotn beleive me or anyone else here you can do this for a test its only 27 seconds. Find a negative cell and apply you theory to it. Move in that direction by 10-20% and see what happens. I bet you'll come back and edit the post.....

I can also tell that you arent doing this by hand but are doing this with the copy paste feature. If this is the case look at a previous tune and then look at the one you just made and you will see with your own eyes that -LTFT cells get fuel taken away (lower ve values) and + LTFT cells get fuel added (higher ve values)

WORD TO YOUR MOTHER

[12secSS]

Man, a simple typo and you guys get very defensive. Sheesh, what happened to being nice and helpful. Sorry, didn't mean to insult you with my typo.

[MNR-0]

I still prefer the older method of adjusting your IFRs when running a MAF. VE and MAF re-cals change like the wind - literally! Adding to the air calcs. stuffs up a whole loot more than the IFR ever will. For example, raising measured air volumes can:

alter shift firmness for A4s
change the WOT path along your spark table
alter delivered TQ calcs hence all TQ related limiters

My approach is to get your Ariflow Modes in clsoed loop fuelling at optimum resolution then linearly rescale your IFRs. Its also good to be able to maintain a baseline cylinder fill to determine the performance gains of any mods down the track.

[Dirk_Diggler]

Man, a simple typo and you guys get very defensive. Sheesh, what happened to being nice and helpful. Sorry, didn't mean to insult you with my typo.

Your post had such conviction it, I had to set you straight. No harm we are still very helpful