PE tuning-confused???

[kevmo777]

I'm satisfied with my ve table, maf table and spark table, now I'm working on my PE table. All that I've read tells me that if my afr is low <12.7 that I need to subtract from my table and add if >13.0. Well I did about 6 runs this morning and it seems that the more I subtract from the table, the lower my afr's go. I'm sure I'm missing something simple. I need a professional to tell me what I'm doing wrong. The car is a '01 Z06. Mods to the car are headers and high flow cats, x pipe, no mufflers. Thanks for any help. The scans and programs are as follows: the first is before I started (stock file), second is after I give up trying.
Attachment 22868

Attachment 22869

Attachment 22870

These are what I ended up with:
Attachment 22871
Attachment 22872

[angrygoat]

The PE table should not be tuned. It should be set and left alone. You set it at the AFR you want to run at and forget it. If after you set the AFR and log a WOT run and your AFR is still not matching, then either you VE or MAF transfer is off. To find out what to SET your PE table to, divide 14.7 by the AFR you want to run.

EX: 14.7/13.0 = 1.1307 <--- this is what you put in your PE table across the board

[kevmo777]

The PE table should not be tuned. It should be set and left alone. You set it at the AFR you want to run at and forget it. If after you set the AFR and log a WOT run and your AFR is still not matching, then either you VE or MAF transfer is off. To find out what to SET your PE table to, divide 14.7 by the AFR you want to run.

EX: 14.7/13.0 = 1.1307 <--- this is what you put in your PE table across the board

So then, if I set my table to read afr of 13:1 and I'm reading 12:1, do I adjust my ve table and maf at the same time or seperate (like the fuel trims)? This case I would subtract from the ve table and maf table-is that correct? Thanks. This is different then what "Tuning the right way" instructs.

[SweetS10V8]

IF you command 13 and you get 12, your VE/MAF numbers are too high and your getting too much fuel. You have to lower the numbers, your VE/MAF must not be correct.

[mowton]

So then, if I set my table to read afr of 13:1 and I'm reading 12:1, do I adjust my ve table and maf at the same time or seperate (like the fuel trims)? This case I would subtract from the ve table and maf table-is that correct? Thanks. This is different then what "Tuning the right way" instructs.

As stated above by angrygoat, set PE to what you desire and tune the VE and MAF (separately) as you would normally. Whats important is you can not tune the PE without a wideband. SweetS10V8 is correct, your MAF and o VE is not tuned properly at thos rpm area's.

The only difference between how you have been tuning outside PE is the commanded AFR. It will transition from Stoich to what ever you set the PE Equivalent ratio to at that RPM area. The AFR error percentage derived from the difference between the commanded and actual AFR continues to be your multiply factor. Once you have it tuned. You can merely change the PE value, and the AFR will follow with no error.

Ed M

[Frost]

So then, if I set my table to read afr of 13:1 and I'm reading 12:1, do I adjust my ve table and maf at the same time or seperate (like the fuel trims)? This case I would subtract from the ve table and maf table-is that correct? Thanks. This is different then what "Tuning the right way" instructs.

Are you saying that you purchased some type of tuning help material (book, workshop, whatever) that tells you to tune WOT by moving around PE numbers rather than calibrating your VE/MAF? Maybe they meant AFTER calibrating the MAF so that you get what you command AFR-wise, then you change PE. Maybe?

[KLUG'S SS]

If a book, dvd, etc.. was purchased with info stating that it's ok to "rape" your PE table then I would get your money back and tell them to burn that material.

[angrygoat]

I know thats what the tuningschool was publishing in their beginner's course until they added that supplement last year

[kevmo777]

If a book, dvd, etc.. was purchased with info stating that it's ok to "rape" your PE table then I would get your money back and tell them to burn that material.

This is the document I was using "Tuning the Right Way" by Bob Morrale. See attachment for pages explaining pe tuning.

I'm understanding the proper way to tune using maf/ve tables, but could someone explain to me why when I lowered my pe multiplier, my afr's went lower???? Is my config set up right?? If I'm understanding the ve tables, that would be the same as lowering thier values?? I have studied this trying to make sense of it, but can't come up w/ a reason why I got the results from the changes I made. Thanks again.

[kevmo777]

I know thats what the tuningschool was publishing in their beginner's course until they added that supplement last year

Where can I find that supplement? Thanks.

[69lt1bird]

You should turn off the cat over temp CAT while you are tuning.

[kevmo777]

You should turn off the cat over temp CAT while you are tuning.

Is that the reason that why I'm not getting the results I'm looking for? Do I need to be concerned about hurting my cats? I'm running high flow cats, w/ my rear o2 still enabled, that is why I never turned off the cot.

[69lt1bird]

You can turn it back on after you are done tuning. It will mess with your fueling while you are tuning, if you get the VE and MAF tables setup correctly you can turn it back on.

Like these guys said, the PE tuning method in that edition is not right. Just trust your wideband, set the AFR to what you want and tune the VE and MAF tables to that number.

[SweetS10V8]

Where can I find that supplement? Thanks.

Call Bob @ the Tuning school, tell him you are looking for the updated VE & MAF tuning supplement. He sends out a 1 time viewable link for you to print out. Or he can probably send you a copy through UPS.

You have to have your serial number obviously and probably have to of purchased the book within the last year.

Have you looked at the free link in LT1Birds sig?