ZL1Killa

iTrader: (17)

I looked at my log of my car with EFI Live scantool and found at around 2krpm I'm getting 5.3 degrees of Knock retard and my ltrims are staying positive almost all the time (up in 10's and 20's)...I'm assuming I dynoed like this and the car made 374HP and 388TQ? the place that dynoed my car didn't say anything about it spark knocking...nor can I or my dad tell

Well, I have done LSX intake mani (90mm), NW TB, Kooks 1 3/4 headers, no cats, turned off cat protect, and tried to lean out my car via the PE based on rpm. I also adjusted my injectors for the actual 54psi that my fuel pressure is (stock 28.8# injectors). When I did so the numbers in g/sec went up, from 3.6172 @ 0kPa to 4.0391 @ 0kPa (using the spreadsheet from RedHardSupra) is this the way that it is supposed to go or is it supposed to get smaller?? I think I'm wrong on that because all that has been discussed..

anywho..anyone got some advice??
I'm going to richen back the PE table and mess with the VE table today and see what happens...

I don't think its going to be that big of a deal since within the next few days I will have a Wideband and I will be doing the SD autotune write up at EFI LIVE


here is the log if anyone wants to take a look..

WS6FirebirdTA00

iTrader: (33)

how did you get actaul fuel pressure of 54? throw a gauge on there and check. stock fuel pump for me 58 psi. with it in at 54 it will be running richer, plus the injectors are rated at 58 psi (4 bar). reset the fuel trims and relog. too rich a mixture can cause knock as well. what is your timing set to in the areas you get knock? and is it just at wot? i would think a ve table that is off could cause this as well as pe table and ifr table askew. what is the pe set to right now? and what readings are you getting on the o2s?

ZL1Killa

iTrader: (17)

woh....okay um.... we measured the fuel pressure with a gauge (the fuel pressure previously was 43.5-set at stock tune; we then measured it and found at WOT that the pressure went down as low as 56psi so we just picked a safe number and used 54psi).

What do I do to reset the fuel trims?? just throw a tune in right (even the same tune)??? We know from the dyno that the car is running about a 13.6:1 ratio under 3krpm and above that it is running a 12.1:1 ratio What my dad thought was since it was at 2k and from the log we were coming off of the throttle that it was running to lean at decel (w/throttle blade closed)

I KNOW our VE table is off. I also have changed the pe table to run from 13.6 down to 13.0 at high rpm...

WS6FirebirdTA00

iTrader: (33)

well get the ve back in line and then do pe to richen it up down low. check out what your fuel pressure is at idle and some other vacuum points and create a table based on that. ive seen odd fueling with ifr table being off. like i said in the other post, my stock tune was set to 58 psi right on the nose up to 5 decimals, not a thing different about it. maybe someone tinkered with the car at one time? i dont know. thats normally the wrong way most tuners richen a car up. you woudlnt believe how rich 4 psi would make the car, its enough to matter.

resetting the fuel trims in hp tuners can be done iwht the scanner, dont know about efi

ZL1Killa

iTrader: (17)

ok well messed with the VE table and PE table and it dropped to 2.9 kr @WOT around 5krpm...lol

WS6FirebirdTA00

iTrader: (33)

what is your timing going to at WOT?

WS6FirebirdTA00

iTrader: (33)

before KR

ZL1Killa

iTrader: (17)

22.5 at knock retard about 25 before it started. You are talking about the spark adv right?

WS6FirebirdTA00

iTrader: (33)

yeah, set the pe all to about 1.14 and go out and tune. look for lean spots in the table, have to look at the o2s until you get the wideband. whatever the values are now do this.

(old value/new value)+0.02= what to multiply yuor ve table by from 80 kpa and up. this will correct the ve table and richen it up some as well. try that and work from there on it. make sure the trims are reset as well.

ZL1Killa

iTrader: (17)

we modified the PE table and that seemed to make things worse around 44-4800rpm

here is a screen shot, I will do what you said mike...then i'll let ya know

WS6FirebirdTA00

iTrader: (33)

ok, ill check on something else when i get home too

ZL1Killa

iTrader: (17)

alright...mike I followed what you said. I used 1.13 instead of 1.14 and then i just went out and logged. After pulling out onto Wilson's 2nd main drag and going throttling it up till I hit 50mph I noticed the KR went to 1.6 degrees once I let off the throttle after going into 2nd gear. This is the first screenshot--1.6kr


So I stopped and saved that log and went down the second strip again. On this run I was nailing it thru 1st and 2nd--then saw the kr of 1.1 degrees and this was at full throttle about to switch from 1st gear to second gear--screenshot-1.1kr

this kr seems to be happening right after I let off the throttle when it passes under 5krpm ??

WS6FirebirdTA00

iTrader: (33)

i would keep tweaking the VE table, sounds like its getting better though right? what are the fuel trims now? and what do the o2s read? at wot

ZL1Killa

iTrader: (17)

well what I did was change the PE table to 1.13 all over. And what is really funny is that I had a stock 01 corvette 6spd tune....so I compared VE's and just pasted the 01 vette VE in place of my VE..that moved the spark retard from 2k to the 5k...LOL

so now I have 1 degree of spark retard at around 5k. Would you say add to the ve around those areas or take away values from those areas??

DAMN I NEED A WIDEBAND!!!!!!! C'MON DYNOTUNE.ORG SHIP IT!!! FAST!!! LOL

WS6FirebirdTA00

iTrader: (33)

yeah you want to get the ve right, cause that commanded afr shoudl be ok, but the wideband will tell you the truth

ZL1Killa

iTrader: (17)

ok well we lowered the PE table down to 1.12 from 5k on up and it gave us 0.5 kr in degrees

so then for kicks i did 1.11 from 5k on up and I now have no knock retard


Now, mike. what are you saying i should do with the VE table?? I should get my wideband sometime soon here and I read the SD tune from EFI LIVE. What have you done to tune yours?? do you have a MAF??

ALSO...

Add to numbers in the VE table does what??
Take AWAY from numbers in VE table does what?? (i think i remember this but just checking )

WS6FirebirdTA00

iTrader: (33)

adding makes it richer, and vice versa. its odd that lower pe helped. that means you leaned it out. what where your o2 voltage readings at WOT?

TAQuickness

iTrader: (28)

I just looked at the log in your first thread... You really need to work on the VE table.

You are running very lean. Positive Fuel trims indicate you are running lean. Negative indicate you are running rich.

When you add to the value in the VE table, you are telling the PCM there is more air in the cylinder, and therfore get more fuel.

When you subtract from the value in the VE table, you are telling the PCM there is less air in the cylinder, and therfore get less fuel.

Can you post a recent log?

ZL1Killa

iTrader: (17)

if anyone has EFI LIVE...TAQUICKNESS do you?? I can send you my tune file and see what you think.

My Air/fuel ratio meter (connected to the O2's) says that it is rich...?? at WOT

there are two log files attached. The one titled 0.5KR is the one where PE was changed to 1.12 above 5krpm and the one titled none is where the PE table was changed to 1.11 above 5krpm

ZL1Killa

iTrader: (17)

should i set the PE table to say run at 13.0:1 air to fuel (based on a 14.63:1 stoich) and then mess with the VE table (go ahead and increase it by a good percentage??)

My wideband will be here Monday... but it is being shipped and it was handled with speed...DynoTune.org is awesome!!! Dean even called me to answer any questions I had.

I'm thinking about looking at the LTFT's tomorrow and seeing where they are going high and adjusting the VE table higher at those areas and leaving it alone until I get my wideband