Injuner or some with good tunning skills need help

[iwon]

How do i use this table...

%change to fuel/air ratio vs. cool temp. at wot

do i lower the amount to lean out , and raise the number to richen?

also is there a forumla used to caculate the amount to add or subtract?

what affects will 10 less from 34.4 at 20 degrees C, equal how much with the o2s drop?

and should this table be used over

%change to fuel/air ratio vs. rpm at wot.

but note when i used %change to fuel/air ratio vs. rpm at wot.
to lean out i droped every table by .1 which cause extreme lean conditions.

and one quick question, is there any long term affects of lieing to the computer telling it theres larger injectors there then what are really there.

i only say this cause me and my friend are on the verge of just putting his 24 pound injectors back in if we cant get the rich condition under control
soon.

so any help will be grateful


[This message has been edited by iwon (edited July 24, 2002).]

[Injuneer]

I can't really help you with the stock PCM... I don't use it, I have a MoTeC. I think Chris Bennight has some good info on how to use the PE tables.... try this link, and it may lead you to others:

http://www.carprogrammer.com/Z28/PCM...g%20Advice.htm



------------------
Fred
94 Formula A3: 381/TH400/N2O

Advanced Tech Posting Guidelines
Detailed Mod's List
11.513@115.59 on motor; 11.162@127.67, 1.643 60' on a 125-shot. Going with a 275-shot this year

[iwon]

"It takes a lot of change to make a difference of just 1/2 a point AFR ( like 6-7 % PEvsRpm in my experience.)"

i have this printed out and i read this and the supercharged version also.

TunnerCat dosnt say Pevs.Rpm but im guessing that the table i was talking about "is the same table in LT1_edit" am i correct?

where i first learned of changing this table was this article that the lt1 edit guys had in there advanced tunning sections


At 176 Degrees F (where my car was running at the dragstrip), I changed the values to:

3200: 0
3600: 2
4000: 1
4400: 2
4800: 2
5200: 2
5600: 2
6000: 3
6400: 3
6800: 3

And end up with AFR's of

3200: 12.348
3600: 12.054
4000: 12.201
4400: 12.054
4800: 12.054
5200: 12.054
5600: 12.054
6000: 11.907
6400: 11.907
6800: 11.907

As opposed to the stock AFR's of:

3200: 12.348
3600: 12.054
4000: 12.201
4400: 12.054
4800: 11.025
5200: 10.878
5600: 11.319
6000: 11.907
6400: 11.907
6800: 11.907

And this dropped my O2 numbers from mid 900 mV's to high 800 mV's.


Now the only that is weird is that he droped his by atleast "1" point his o2s fell to lean but not to dangerous mid 800's.

when i droped my friends by ".1" his o2s went to 820-840 which i feel is way to lean.

basicly what i want to know is is there any way i can lower this , cause i did see the o2s drop Buttt by not so much.

thanks alot-Nick

[Injuneer]

You are putting way too much faith in the OEM narrow-band O2 sensors. They are not that accurate at the A/F raitios we want to tune for. The curve of lambda (A/F ratio) vs. mV's is so flat that a very large change in A/F ratio makes a very small change in mV's. But, the sensor is EXTREMELY sensitive to its operating temperature at these A/F ratios, and a change in operating temperature can cause more change in mV output that a change in A/F ratio.

You really need to be careful with these. I would say after you think you have it close, put is on a chassis dyno with a wideband and verify everything. Do not rely heavilly on the OEM O2's.

[iwon]

i completely agree with u on that, but really we just want to lower it enough so, it dosnt backfire and spit raw fuel at idle, i have the stain marks to prove it :^).

hmm but do u know if saying it has 38 instead of its 36 will cause harm? will that throw the S-trim L-trim?

thanks for all ur help before and thanks for what ever else u give me