Yes, definitely the same here. The coolant needle is always leaning left lol
Makes sense why 150 IAT2 isn't near a death sentence for the timing on E85...cylinder temps stay low that sensor upstream just doesn't realize it
Lets talk Iat2
- Thread starter JuStAkId
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Yes, definitely the same here. The coolant needle is always leaning left lol
Makes sense why 150 IAT2 isn't near a death sentence for the timing on E85...cylinder temps stay low that sensor upstream just doesn't realize it
I know you have a timing table that shows that. Some others seem to have a contradicting table. I am getting an email tune from Lund right now that is supposed to address this. I don't have any tables of my own to prove it, just what I have learned from here and Modularfords. Hopefully someone else can chime in
Anyone who has access to SCT tuning software or similar can open up the stock tune as it comes from Ford and show you the same thing.
Yeah both pictures i posted were me on the freeway. My IAT1s will be at just about ambient. In stop and go they will shoot way up.
I dont see how timing can only be pulled past 150?? If i make my runs any my IATs are starting at 120-125 ill run 2-3mph slower than if i cool it down and run with IATs at 100ish. EVERYONE i have talked to says after 100 its a progressive table the limits your timing. Plus with my Aeroforces i can see timing at WOT and it seems to change quite a bit based on IAT temps.
I dont see how timing can only be pulled past 150?? If i make my runs any my IATs are starting at 120-125 ill run 2-3mph slower than if i cool it down and run with IATs at 100ish. EVERYONE i have talked to says after 100 its a progressive table the limits your timing. Plus with my Aeroforces i can see timing at WOT and it seems to change quite a bit based on IAT temps.
Anyone who has access to SCT tuning software or similar can open up the stock tune as it comes from Ford and show you the same thing.
Malcolm is right. I checked on this last night as I was tinkering with the tune on mine. I think I dropped mine to start pulling timing at 135 degrees, I wish my town would bring E85 then I could spend another few $1000 on fuel system mods and start my tune all over again lol.
My Vampire shows no hint of detonation on my combo pre 150F IAT2s so I've left mine as is.
Good to know. I actually turned mine back to 150 in my tune last night. I don't know why but last night when I was logging I was getting one degree pulled from some where even though my IAT2s were below the 135 mark, the only change I had made was that table. After all that I read in LaSota's book that at 150 degrees you're probably detonating but just don't know it, so its good to hear from someone with equipment to comment on it. Now I just need to find what is pulling my timing at WOT.
That's tough to figure out because so many things affect timing. IAT2 is just the common one most people know. Also remember to check load/RPM etc. and look in the spark tables and see what currently commanded timing was at that spot. Most people just look for one number like 18 degrees or whatever and when they don't see it assume the car is pulling timing. But as you know commanded timing will vary greatly depending on load & RPM among other things and it's not always timing been pulled. It would be nice if there was a PID to datalog pulled timing and perhaps a second PID of codes that tells you want modifiers specifically are pulling it.
It exist in some other PCM, its called KR, knock retard, it will tell you how much timing is pulled. Not having a knock sensor on our cars doesn't help for that...
Right. That would tell you for knock but the ECU will also pull timing for various other reasons, coolant temps, intake air temps, engine load etc. I don't know them all by heart but there's a few.
I wonder too if things changed with later production runs as I see Malcolm has an 03. I had always thought the 04s did pull tiny amounts between 100-140 then a major amount at 150. My computer code is AMZ1
What I showed above is from AMZ2 the final strategy Ford released for these cars. I've also gone back and checked YDH1 which I believe was one of the first and it's exactly the same at 150F.
My load at max is only about 1.8, I set my top two rows in the borderline table to be identical and renormalized them so my top row is 1.999 and my second is about 1.60 instead of 1.699. I didn't like that my load drops down into the low 1.7's that's was too close to the 1.699 and didn't want to drop into my next lowest cell and command more timing. I wish my load was higher but when I went BP modifier method and return I really had to cut a lot of fuel out of it and that brought load down. I think the top two rows were 16.5 and it was commanding 15.5.
Edit: How did you get to look at YDH1?, I thought the only strategy that's available was AMZ2.
oh, ok. Well, there goes that theory. I'm sure its the same for all then.
Not that I plan on running a stock tune any time soon (lol)...but still good info to know. Thanks!
Nope you can get YDH1 as well. SCT says AMZ2 is better but have no explanation as to why.
Anyone who has access to SCT tuning software or similar can open up the stock tune as it comes from Ford and show you the same thing.
The PCM interpolates the values between the two points. For example, at 100* total spark retard will be 0*. It will progressively increase until it reaches 150* and then spark will be retarded -60 multiplied by the value in the correct position in the "Spark Retard ACT Multiplier" which is based on load vs RPM.
So, halfway at 125* IAT2 the PCM should derive a value of 30* and multiply it by the current position in the "Spark Retard ACT Multiplier" table. At say 1.3 load and 4000 RPM the value is 0.0507. 30*0.0507 is 1.52* of spark retard.
If you wanted to not have spark retarded until a specific IAT2 you would need to explicitly have that value in the table and put 0 in for the value.
Interpolation is done everywhere in the PCM. The MAF Transfer Function is a good example.
Riley
Great post glad you did it because I was about to try to post something similar but no where near as well written. I just ran another log and my car is pulling a little over a degree. I got to thinking that EEC interpolates between values in other tables so why wouldn't it in this one. After doing my best to do the math and using all the multipliers i got a number of spark retard similar to what I was seeing in my log.
Now what I'd like to know is when you hear people mentioning how much timing they got if that was before or after the mulipliers go into effect.
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I know my IAT2 temps would fluctuate between 25-30* over IAT1 while just cruising.
Great to know! Devil is always in the details! Lol
I really need to get that lasota book and a copy of prp.....won't be making any significant changes as my car runs awesome....but would be a great way to learn
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