Can't seem to lean out the A/F
#1
Can't seem to lean out the A/F
Did some monitoring over the weekend on the A/F and I'm running in 9.5s in every gear. I lowered the base FP from stock to around 27-28psi but it doesnt seem to make much of a difference, now around 10 A/F. Before, I did lowered my FP and my A/F went to 10.5 and I fined tuned with a SAFC but I havent touch the SAFC yet. I'm worried that if I keep this base FP, my correction factors is going to be around 15% which may affect my timing. I get 14.7 at idle and crusing so I know I'm not lean there but I just can get the WOT A/F to come up a bit. I dont mind running rich but 10.0 is a little tp much and my MPG is crappy.
Do you guys think I can get away to maybe lowering the FP 1-2 psi and tuner from there or should i keep the FP now and tune from there? I have yet to install J&S so it will help with the timing if I go this route.
BTW I'm running 500cc DW, z32 maf and stock ecu.
Do you guys think I can get away to maybe lowering the FP 1-2 psi and tuner from there or should i keep the FP now and tune from there? I have yet to install J&S so it will help with the timing if I go this route.
BTW I'm running 500cc DW, z32 maf and stock ecu.
#2
Originally Posted by jcy98maxse
Did some monitoring over the weekend on the A/F and I'm running in 9.5s in every gear. I lowered the base FP from stock to around 27-28psi but it doesnt seem to make much of a difference, now around 10 A/F. Before, I did lowered my FP and my A/F went to 10.5 and I fined tuned with a SAFC but I havent touch the SAFC yet. I'm worried that if I keep this base FP, my correction factors is going to be around 15% which may affect my timing. I get 14.7 at idle and crusing so I know I'm not lean there but I just can get the WOT A/F to come up a bit. I dont mind running rich but 10.0 is a little tp much and my MPG is crappy.
Do you guys think I can get away to maybe lowering the FP 1-2 psi and tuner from there or should i keep the FP now and tune from there? I have yet to install J&S so it will help with the timing if I go this route.
BTW I'm running 500cc DW, z32 maf and stock ecu.
Do you guys think I can get away to maybe lowering the FP 1-2 psi and tuner from there or should i keep the FP now and tune from there? I have yet to install J&S so it will help with the timing if I go this route.
BTW I'm running 500cc DW, z32 maf and stock ecu.
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#3
well the thing is, at 5psi I was running 9.5-9.6, i did all that and it went to 10.0. Then I thought okay, turn up the boost to bring more air into the motor, it'll lean it out a bit. Well I up the boost to 8psi and saw no different it was still pinned at 10.0-10.1. I was like WTF, I think I'm gonna datalogg sometime this week to see the whole graph. I had a passenger watch the display while I was on it so I didnt see it first hand.
#6
well theres some conflicting data, I think I30Mike and another person did some timing log and for some reason it didnt affect timing as much as it did. But thats just based off of a small sample. Advance timing isnt good for boost but niether is too much timing retard. I'm just trying to get some opinions on what I should do in regards to my situation.
http://forums.maxima.org/showthread....ht=safc+timing
http://forums.maxima.org/showthread....ht=safc+timing
#8
Did some SAFCII tunning, overall baseline datalogg shows a 10.0-10.3 A/F, did some negative adjustments on the SAFCII (at most 13%). Got the A/F to be a steady 11.5 uptop, still need to fine tune midrange but from 5k on its right at 11.5.
#12
well the safc hasn't really affected timing as much as poeple thought, this in relation to the old thread about the SAFC correction vs timing.
Plus my corrections aren't extremely high, the max at the moment is still less then 10%. I'll be installing the J&S shortly so I can have it at least monitor knock retard.
Plus my corrections aren't extremely high, the max at the moment is still less then 10%. I'll be installing the J&S shortly so I can have it at least monitor knock retard.
#13
Originally Posted by jcy98maxse
well the safc hasn't really affected timing as much as poeple thought, this in relation to the old thread about the SAFC correction vs timing.
Plus my corrections aren't extremely high, the max at the moment is still less then 10%. I'll be installing the J&S shortly so I can have it at least monitor knock retard.
Plus my corrections aren't extremely high, the max at the moment is still less then 10%. I'll be installing the J&S shortly so I can have it at least monitor knock retard.
Mike
#14
Originally Posted by mforrest100
I noticed that you are the second person that is going to run the J&S with knock retard only and not boost retard. I think i get that the point of getting the J&S unit is to prevent detonation by retarding the cylinder where the knock is coming from (correct me because I feel like i am 60% off) but why wouldn't you want it to retard the boost if it may sense the engine knocking.
Mike
Mike
Also I did consider just running knock monitor since I'm running stock timing, which the general consensus is good for around 9-10psi. With just the knock monitor you can running at "maximum" amount of timing and if/when it detonates, the J&S can catch it and retard it back at that point in time. Although this would work, I think it would wiser/safer to use the boost retard feature to retard a little bit of timing around that point and go from there.
So the plan is to install the unit first and getting it going before I turn the boost any higher and play with the boost retard at the time. Meanwhile, my 8psi spring is doing just fin and the A/F is not too bad.
#15
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I wouldn't be worried about the SAFC corrections your making to get to the ARF your at. From my expierence it doesn't mess with timing to any significant degree.
To the person who said to just turn the boost up to lean things out, that is not how it works. The maf will just register more and and add more fuel. There might be a slight change in AFR when upping the boost but not enough to make a huge impact.
To the person who said to just turn the boost up to lean things out, that is not how it works. The maf will just register more and and add more fuel. There might be a slight change in AFR when upping the boost but not enough to make a huge impact.
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jmlee44
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10-02-2022 02:13 PM