Predator newbie, need help with my first tune>>
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Predator newbie, need help with my first tune>>
Trying to read up as much as I can with the little time I have, lots of good info out there, but still all very confusing to me as this is one aspect in automotive I've always overlooked. I know have a Predator with S/W 1.03v. Not sure if 1.04v came out yet? Anyways, need help tweaking the stock uploaded tune the Predator flashed my pcm with. Below are the numbers I was able to get with a passenger writing them down.
Mods: Direct Flow Lid, Green Filter, Smooth Bellows, and Jantzer ported TB, stock thermostate, stock everthing less the suspension work.
Idle (ECT = 217* @ 780-808rpm):
LT Bank 1: 0.78% steady
LT Bank 2: 2.34% steady
Spark: 21.3-23.8
H02 Bank 1 Sens 1: 700-850mV (jumping)
H02 Bank 1 Sens 2: 790-800mV
H02 Bank 2 Sens 1: 700-790mV (jumping)
H02 Bank 2 Sens 2: 770-785mV
Knock Retard: 0
Cruising (55mph, 5th gear, 1800rpm, IAT = 69*):
LT Bank 1: 4.69%
LT Bank 2: 3.91-4.69% (jumping)
Spark: 35.4
H02 Bank 1 Sens 1: 750-760mV
H02 Bank 1 Sens 2: 760-775mV
H02 Bank 2 Sens 1: 770-775mV
H02 Bank 2 Sens 2: 770mV
Knock Retard: 0
WOT (2nd gear, pedal to metal, up to 5700rpm, IAT = 69*):
Spark: 26.9
H02 Bank 1 Sens 1: 900mV
H02 Bank 1 Sens 2: 915mV
H02 Bank 2 Sens 1: 895mV
H02 Bank 2 Sens 2: 905mV
Knock Retard: 0
*NOTE* (ranges were hard to get when pinned to the seat)
Now from what I learned, we don't look at the short term banks, but only the long term as they seem to stay steady. WOT H02 Banks should be in range of 890-910mV of which looks like I'm within spec, less Bank 1 Sens 2 by 5mV. My Fuel Trims, or Long Term Banks seem to be running high + numbers meaning the pcm is adding in fuel to offset a lean condition? My WOT spark should be in range of 27-30*? So does this mean i can increase mine?
At this point I am pretty much lost in what to do. Do I reduce PE to compensate for the High LTrims? But this in essence would lower my H02 reading causing a lean WOT?
Please help, not sure what to do with this...
Oh, at the top of the rpm I heard a slight difference in the exhaust note, or engine tone, almost like sparking type noise or pinging as it could be? Dunno, still dead 0 on the knock retard. Please take it slow with me as I don't know all the termanology and their meanings, theories, etc.
Thanks for any help!
Mods: Direct Flow Lid, Green Filter, Smooth Bellows, and Jantzer ported TB, stock thermostate, stock everthing less the suspension work.
Idle (ECT = 217* @ 780-808rpm):
LT Bank 1: 0.78% steady
LT Bank 2: 2.34% steady
Spark: 21.3-23.8
H02 Bank 1 Sens 1: 700-850mV (jumping)
H02 Bank 1 Sens 2: 790-800mV
H02 Bank 2 Sens 1: 700-790mV (jumping)
H02 Bank 2 Sens 2: 770-785mV
Knock Retard: 0
Cruising (55mph, 5th gear, 1800rpm, IAT = 69*):
LT Bank 1: 4.69%
LT Bank 2: 3.91-4.69% (jumping)
Spark: 35.4
H02 Bank 1 Sens 1: 750-760mV
H02 Bank 1 Sens 2: 760-775mV
H02 Bank 2 Sens 1: 770-775mV
H02 Bank 2 Sens 2: 770mV
Knock Retard: 0
WOT (2nd gear, pedal to metal, up to 5700rpm, IAT = 69*):
Spark: 26.9
H02 Bank 1 Sens 1: 900mV
H02 Bank 1 Sens 2: 915mV
H02 Bank 2 Sens 1: 895mV
H02 Bank 2 Sens 2: 905mV
Knock Retard: 0
*NOTE* (ranges were hard to get when pinned to the seat)
Now from what I learned, we don't look at the short term banks, but only the long term as they seem to stay steady. WOT H02 Banks should be in range of 890-910mV of which looks like I'm within spec, less Bank 1 Sens 2 by 5mV. My Fuel Trims, or Long Term Banks seem to be running high + numbers meaning the pcm is adding in fuel to offset a lean condition? My WOT spark should be in range of 27-30*? So does this mean i can increase mine?
At this point I am pretty much lost in what to do. Do I reduce PE to compensate for the High LTrims? But this in essence would lower my H02 reading causing a lean WOT?
Please help, not sure what to do with this...
Oh, at the top of the rpm I heard a slight difference in the exhaust note, or engine tone, almost like sparking type noise or pinging as it could be? Dunno, still dead 0 on the knock retard. Please take it slow with me as I don't know all the termanology and their meanings, theories, etc.
Thanks for any help!
Last edited by SilverSmoke; 09-28-2004 at 02:00 PM.
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Damn you took it up to 6700rpm From what you've said you have stock cam and internals so you don't need to go past 6000rpm. My predator set my timing at WOT to 31 so I don't think you need to increase it much if anymore. Just keep increasing your PE until your LTFT's go to 0 at WOT. Increasing PE mean you'll run richer at WOT. Decreasing PE will only make your positive LTFT's at WOT even higher which means you'll run even leaner.
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Originally Posted by SilverSmoke
WOT (2nd gear, pedal to metal, up to 6700rpm, IAT = 69*):
My WOT spark should be in range of 27-30*? So does this mean i can increase mine?
Oh, at the top of the rpm I heard a slight difference in the exhaust note, or engine tone, almost like sparking type noise or pinging as it could be? Dunno, still dead 0 on the knock retard. Please take it slow with me as I don't know all the termanology and their meanings, theories, etc.
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ill read more later but if high rpms u hear or think u hear pinging then add some fuel, about 1.5% and see if it goes away, if not go up another percent and that should fix it if its it pinging based on your o2 readings, yeah they really dont mean much but can help. my car likes it abut 920 mV. i wouldnt go over 29* of timing at WOT all the way up to redline. u need the fuel trims tuned to under 0% so u can get the WOT tuned better i think. send that info to diablo and get a tune. sorry i read thsi fast so if i repeated something or didnt say enough ill get back later