As I read and make notes in some books I bought , I figured there is some things to share here, that people don't seem to talk about too much on the interwebs when I've been doing my information hunts.
CK5
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Into the rabbit hole of EFI tuning. ( Speed density/VE )
- Thread starter bix
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This should be helpful, nice find.
This should be helpful, nice find.
What struck me with this right away is most of our fuels here are " up to 15 % " ethanol unless you buy premium which is stated as Ethanol free or close to. So right off the bat all the information about having my ECU trying to accomplish 14.7 AF ratio, which is what everyone talks about, is wrong for the fuel thats in my tank right now. With premium fuel being around 1.75 a LITRE, ive contemplated running e85 in it for the perfomance and cheapness. But thats for when i actually know how to tune this thing better.
This book is to say the least very informative.. many of these equations wont find space in my head to live permanently, but its so interesting to know what my ECU is actually doing in a Speed density / VE system to calculate injector pulsewidth , and therefor fueling to match the air thats entering each cylinder
I figured with the proflo/holley systems that a few guys are running on here , this information might help some.
I'm basically just gonna puke stuff into here that I'm learning as someone who knew nothing before getting this Holley system, and honestly always thought you'd have to be pretty big nerd...
Turns out I am a nerd for the details... So naturally I've taken a liking to all this stuff, even though I'm going to have to re read this book a few times I'm sure, plus others depending how far I want to learn... Hense the rabbit hole because I can be a tad neurotic and compulsive when it comes to information.
Some more stuff I learned today .
Turns out I am a nerd for the details... So naturally I've taken a liking to all this stuff, even though I'm going to have to re read this book a few times I'm sure, plus others depending how far I want to learn... Hense the rabbit hole because I can be a tad neurotic and compulsive when it comes to information.
Some more stuff I learned today .
Yeah, as soon as my terminator finally gets here I'll have to jump into tuning head over heels myself.
Good info
I hear ya there. I'm in the same boat! I can't own a rubics cube and be okay with only finishing one layer. Luckily the Holley system is set up to be pretty easy to use but, I want to get to the point where I can have my learn compensation at 10%. And do all my changes myself when I notice a problem area and then tune correctly for power adders when the time comes for a pro charger or supercharger.
I stumbled upon this publisher of books when I was re assembling my LY5 with AFM. I was very impressed by the small clear font, key information and reference points. And figure it's trust them again when it came to trying this Avenue. So far I know this book already has more than I'll understand in it so I'm happy. Here's the book as reference. It is geared more towards speed density than MAF but still explains maf systems. The same author published another book focusing on MAF systems.
Exactly ,right!? Any power adder being adaptable was a huge selling point for me. Also being able to toss it on more motors as time passes with just a new harness, is not the worst thing either. The dominator is way too advanced for me to begin with, but the terminator seems to be just what i need to last me a few projects, aka 15 years haha.And that's why I went with the Holley.... Future turbo tuning
They seem to be a good publisher. We probably have the same LS book, it covered every aspect of the gen3/4 ls engines. Was impressed compared to the archeaic info in a haynes manual, although they are still worth having for sure.
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To complicate things less, your engine likely won't care one way or another if it shifts a total of a half a point of A/F ratio. Don't sweat the whole 14.56 to 14.7 stoich, that small difference really doesn't matter and you won't be able to feel that, and likely won't be able to measure it on the acceleration performance, especially at low load where you can actually run closer to stoich.
I think you'll find the self tuning is very good on the Holley if you don't have any exhaust leaks and your cam is reasonable, you just need to set it up correctly with the wizard, and it will do most of the work for you.
I think you'll find the self tuning is very good on the Holley if you don't have any exhaust leaks and your cam is reasonable, you just need to set it up correctly with the wizard, and it will do most of the work for you.
ive heard lots of different opinions about the holley system just doing its own thing the whole time.. I know the engine wont be noticably different form 14.7 to 14.2 really but i dont want to run it any leaner than necessary. Also here most fuels have up to 15% ethanol which im guessing would bring the ideal AF ratio down to about 14.0 which seems like a big enough difference but im not one to know really. Just going by what ive read?
Do you mean resonable as in not something thats got 270/280 and 105 LSA ? The cam i have in there is a mild, stage 2 truck cam so im not expecting it to cause too many issues except a bit of a higher idle possibly.. to provide good vacuum.
You talking 270 @ 050 I take it? I'm mainly talking too much overlap. Stage 2? Is that 1/3 race? Or 1/2?
Just kidding. Not knowing what brand you have I am going to assume a truck cam will be fine, unless its a cam for a truck pulling motor, in that case, it likely will need "assistance". The more overlap, the higher the RPM needs to be for it to not get tricked into thinking it's lean from the overlap letting the intake air mix into the exhaust at low RPM, which the O2 sensor sees as lean, and it tries to correct, but it can't.
So as you get more overlap, the trick I like to use is to limit the learning below a certain RPM, up to 2500 RPM depending on the cam, so that it can only remove fuel, and not add it. 0% on fuel adding below that RPM. Then limit the closed loop correction to a small amount, maybe 10% or less on the addition. Then you have to tune below that RPM manually. But with a standard cam, say right around 230 duration @ .050" or below, it will work just fine for the most part. But it does depend on the whole combo, LSA, engine size, etc. Also, this is not a set number or a cutoff, its just about where it can start to cause issues at lower RPM above that duration, below 1500 or something. But again, its more about the overlap, not the duration. For EFI I like to keep the LSA at 112 or above NA, for forced induction then 114-118 depending on the combo. Although if you want a rough idle, a peaky motor, or have a carb then I go lower on the LSA.
Also, when you are tuning at low load cruise, where you can be almost stoich, but I still wouldn't unless its a MPG queen, 14 to 14.7 isn't going to matter much to be honest. Although I wouldn't run it at 14.7 anyway, as stated in the previous sentence.
Just kidding. Not knowing what brand you have I am going to assume a truck cam will be fine, unless its a cam for a truck pulling motor, in that case, it likely will need "assistance". The more overlap, the higher the RPM needs to be for it to not get tricked into thinking it's lean from the overlap letting the intake air mix into the exhaust at low RPM, which the O2 sensor sees as lean, and it tries to correct, but it can't.
So as you get more overlap, the trick I like to use is to limit the learning below a certain RPM, up to 2500 RPM depending on the cam, so that it can only remove fuel, and not add it. 0% on fuel adding below that RPM. Then limit the closed loop correction to a small amount, maybe 10% or less on the addition. Then you have to tune below that RPM manually. But with a standard cam, say right around 230 duration @ .050" or below, it will work just fine for the most part. But it does depend on the whole combo, LSA, engine size, etc. Also, this is not a set number or a cutoff, its just about where it can start to cause issues at lower RPM above that duration, below 1500 or something. But again, its more about the overlap, not the duration. For EFI I like to keep the LSA at 112 or above NA, for forced induction then 114-118 depending on the combo. Although if you want a rough idle, a peaky motor, or have a carb then I go lower on the LSA.
Also, when you are tuning at low load cruise, where you can be almost stoich, but I still wouldn't unless its a MPG queen, 14 to 14.7 isn't going to matter much to be honest. Although I wouldn't run it at 14.7 anyway, as stated in the previous sentence.
Awesome, thanks so much for the info. Its nice to hear things from guys who are experienced in the field, and i can trust. The main problem i was having, was that i didnt have enough base knowledge to understand the different opinions of the internet, and i was getting lost in all the "knowledge"... So i figured lets learn some foundational work, to help me judge what information people are giving out and make my own opinions based on results im getting.
The cam isnt anything crazy, its 218/227 112+2, .522/.524 Lift , I was just throwing an obnoxious number out there to try and relate to what reasonable was as i knew my cam was pretty mild.
Makes sense to alter the closed loop comp % and fuel trim learning percentages down low. My plan was to get a good idle first, good start up cold/hot, and then hopefully let the ecu make corrections from that baseline. I did notice that with the bigger injectors the ECU was removing fuel instead of adding it ther last time i fired it up, and I havent ran any data logs yet or driven it, so really my information gathered is about 5%. Its nice to get some understanding of the whole thing for when the time comes.
I spent $700 to have my terminator x tuned and honestly it made a difference but I'm also tweaking the tune as I go. My closed loop comp % is within 1 or 2 and I'm transferring the learning curve to base every few drives.
I have yet to get the trans to shift properly though, it likes to go in and out of OD.
I have yet to get the trans to shift properly though, it likes to go in and out of OD.
Is it going in and out of OD or is it the converter locking and unlocking? Only reason I ask is I had a dodge that had a similar thing I ended up wrapping the wire from I believe the alternator to the TCM (it's been nearly 20 years so forgive the memory) in foil and that stopped it. It was some electronic interference.
