Sniper EFI for boat.

[rivermobster]

Thanks, I've been called worse. That said, artificial intelligence is better than none at all.

"Opinions are like assholes, everyone has one and the biggest assholes make the loudest noise"
- Unattributed (apocryphal).

I wonder if you realize that what comes out of your keyboard, says more about you than anything else?

It's like you're stuck in a jr high school one-up-man-ship contest, and most of us are over that shit.

It's why we like it here.

So what Exactly brings You here?

 

[DaveH]

Sorry DaveH, I don't mean to be contradicting you at every turn but you are mistaken here again.

"longer pulse means a higher duty cycle which is what creates heat in the injectors."

No. You are assuming that the fuel injectors present a purely resistive (and constant) load and that's the main source of your misunderstanding. If the injector was purely resistive you'd be right, but it's not. Another misunderstanding is your use of the term "duty cycle". There is only one injector pulse per compression stroke and the duty-cycle is mostly dependent on RPM. Third, given the vapor pressure of gasoline, vapor lock in a 'recirculating cooled fuel rail' is impossible at 42PSI (Vortec 8100) and even more impossible at 60PSI (as on all the smaller GM marine engines). If vapor lock was a problem, they'd be INCREASING the pressure on the larger engine, because the larger engine produces more heat.

Heat produced by pintle-in-coil Injectors

1) The copper wire coil in each injector presents an inductive load (as every coil of wire does) and when we talk about the 'ohms' of an inductor we are really talking about 'impedance' -- primarily from 'inductive reactance' (XL = 2Pi*F*L) as the resistance of the copper is trivial by comparison. The thing about Inductive Reactance is that it varies GREATLY with frequency (F) and this becomes incredibly complicated when the voltage waveform is a square-wave (as it is in every EFI system). I won't go deep into the mathmatics (the Fourier Transfom), but there are dozens of injector voltage-vs-current oscilloscope traces on the web you can refer to if you need to see proof. I've attached one below.

2) Moreover, injectors like these are actually little 'solenoids' and they obey the same rules that all solenoids do -- when the injector voltage pulse comes on, there is a huge 'inrush' current flow that moves the iron core 'pintle' to 'open' and then once fully open, the current drops to about 1/5th during the 'hold open' phase. Fuel injectors on these systems are either 'saturated' design or 'peak and hold', both behave similarly, both are actually solenoid-actuated valves. If you've ever built an electromagnetic nail shooter (or it's big brother the RAIL GUN), the voltage vs. current profile is identical.

3) The Ohm's Law formula for the heat produced by any circuit (including injector coils and solenoids) is the formula for power in WATTS -- that's the current (I) SQUARED (!!) times the impedance (L) (in ohms), so the inrush current peak you see on the leading edge of the injector 'on' pulse is a much bigger deal than you'd think -- it produces an exponentially larger amount of heat in the process because that inrush current is SQUARED to convert to power (in watts). You may have heard this described as the "I-squared-R" formula but that's technically incorrect as it applies equally to L and C as well as R.

4) Accordingly, nearly ALL of the heat created by current flowing through an injector coil is created at the instant the injector is energized/opened and only a tiny fraction of total heat is added while the injector is held open for the duration of the pulse.

So...when pressure is reduced on the rail, the longer pulse width DOES allow cooled fuel more time to carry heat away from the injectors, just like I said, and because pressure is reduced this DOES NOT increase total fuel flow! This is why GM reduced the pressure to 42PSI (from 60PSI) in the Vortec 8100. Finally, if you look at the voltage vs current chart below, note that it takes a significant amount of time for the injector pintle to close after the voltage and current go to zero. That's because the pintle has to overcome 'back-emf' and push current back into the circuit, even as it also has to overcome fuel pressure to close and stop fuel flow.

Again, the whole confusion stems from failure to understand the difference between Resistance and Impedance and this confusion is common because both are expressed in Ohms.

View attachment 1374052

ya know i am about done with this. last post.

i come here to share info and my opinion, hopefully helpful to some, not create a hornets nest with other members.

whatever works for you, but may i suggest getting a life? (assuming that is possible and you arent a bot). long winded, over the top and insulting explanations are nothing more then something that has been said long ago....."if you cant dazzle them with brilliance, baffle them with bullshit". The mark of a truly smart/informed person is someone who can explain complex topics in simple terms for the uneducated to understand.

as for your BS on saturated vs peak/hold injectors, the relationship between duty cycle, time and pulse width, just tell me what sort of duty a merc MEFI 4 ecu really sees (all in full throttle and load), and since you mentioned the injection event only happens during the intake stroke, how many times does each injector driver fire the injector for a MEFI 4 at 6000rpm?

 

[RiverDave]

Well I think it’s time for a couple legit Turing tests..

@Racey @DaveH

Post one up and we will see if he passes

 

[white tortilla]

We need @ElectroNautical to go over and assert his dominant knowledge in the moon landing thread.

 

[RiverDave]

We need @ElectroNautical to go over and assert his dominant knowledge in the moon landing thread.

Well it seems to be overwhelmingly confident ignorance in terms of EFI..

 

[DaveH]

Well I think it’s time for a couple legit Turing tests..

@Racey @DaveH

Post one up and we will see if he passes

see post 201. it never said a word. kinda tell me what i need to know.

 

[Rajobigguy]

Congratulations! You managed to demonstrate high incompetence in spelling, english and deductive reasoning in only two short sentences!

Yep, depending on autocorrect is a lot like depending on a MAP sensor to determine how much air an engine is actually using.

 

[ElectroNautical]

ya know i am about done with this. last post.

i come here to share info and my opinion, hopefully helpful to some, not create a hornets nest with other members.

whatever works for you, but may i suggest getting a life? (assuming that is possible and you arent a bot). long winded, over the top and insulting explanations are nothing more then something that has been said long ago....."if you cant dazzle them with brilliance, baffle them with bullshit". The mark of a truly smart/informed person is someone who can explain complex topics in simple terms for the uneducated to understand.

as for your BS on saturated vs peak/hold injectors, the relationship between duty cycle, time and pulse width, just tell me what sort of duty a merc MEFI 4 ecu really sees (all in full throttle and load), and since you mentioned the injection event only happens during the intake stroke, how many times does each injector driver fire the injector for a MEFI 4 at 6000rpm?

So if it's your last post why does it end with a simplistic (and insulting) question? Answering you would either be insulting you OR playing the 'game' you accuse me of right?

So...re: "how many times does each injector driver fire the injector for a MEFI 4 at 6000rpm?" You might as well be asking "how many quarts-per-gallon go over Niagara Falls every hour?" I'd say your questions are far more insulting than my answers, like @Racey asking me "OK smarty, how do you tune air-fuel ratios on a diesel".

Insulting questions like that should will not be dignified with an answer. Thanks for playing. Game over.

 

[ElectroNautical]

Yep, depending on autocorrect is a lot like depending on a MAP sensor to determine how much air an engine is actually using.

And yet, that is exactly how it works, whether you think it's stupid or not.

 

[Rajobigguy]

Any yet, that is exactly how it works, whether you think it's stupid or not.

Any what yet? Oh never mind I guess it's a spelling/grammatical error.

 

[ElectroNautical]

see post 201. it never said a word. kinda tell me what i need to know.

Post 201? Saturday at 6pm I was out on the river, but I wouldn't have dignified @Racey with a response anyway. Glad you learned something though...

 

[4Waters]

Post 201? Saturday at 6pm I was out on the river, but I wouldn't have dignified @Racey with a response anyway. Glad you learned something though...

View attachment 1374139

What river?

 

[Racey]

So if it's your last post why does it end with a simplistic (and insulting) question? Answering you would either be insulting you OR playing the 'game' you accuse me of right?

So...re: "how many times does each injector driver fire the injector for a MEFI 4 at 6000rpm?" You might as well be asking "how many quarts-per-gallon go over Niagara Falls every hour?" I'd say your questions are far more insulting than my answers, like @Racey asking me "OK smarty, how do you tune air-fuel ratios on a diesel".

Insulting questions like that should will not be dignified with an answer. Thanks for playing. Game over.

Well, if it's game over then "Bye Felicia"

 

[ElectroNautical]

So what Exactly brings You here?

What exactly?

I came here because a friend/client of mine had asked me about converting his boat's twin V8 Crusaders to EFI last summer. We talked again last week and he mentioned that he'd decided against it because someone on RDP told him that you can't convert unless you install O2 sensors, and also he'd read (here) about engine fires. I told him MEFI marine engines don't need them and why. I showed him the Volvo Penta 8.1L in my Regal (MEFI-4; no O2 sensors), we walked over to look at a few others in the marina owned by friends (and my son's 2000 Mercruiser 7.4L MEFI-3) and other MEFI-2s and none of them had O2 sensors. Reading through the first eighty or so posts in this thread I began to understand what scared him off but frankly most of it (starting with needing O2 sensors on wet exhaust engines) was dangerous BS based on a lot of experience here with auto/truck EFI systems. Go back and look at my first post here responding to someone's experience with 1980's vintage Ford 5.0L Mustangs and how he used that experience make a number of wrong conclusions contributing to uninformed recommendations.

There's your answer.

 

[ElectroNautical]

Any what yet? Oh never mind I guess it's a spelling/grammatical error.

Got me! Should be "And yet..."

 

[ElectroNautical]

Has anyone done this? What are pluses and downsides? Is there a better choice?
I would really like to swap to EFI vs carb. It’s a 5.7 mercruiser.

Interesting (and last) thing I'll note before I leave this thread...did anyone here ask you about your "Use Case" i.e. "what problem are you trying to solve?"

On my river high octane marine gas is increasingly hard to find and none of our boats ever go on trailers. There are at least 15 river miles between marina gas docks so we have to deal with everything from 87 to 92 octane on any given day. So the #1 reason to upgrade IMO is to get automatic spark retard/advance from a 'knock sensor' signal feeding a MEFI to enable "Octane Adapt". Some of the newer carbuerated engines have knock-sensors but when you don't, an EFI upgrade is one way to do it (assuming the system has an input for a knock sensor).

Good luck with your decision.

 

[4Waters]

What exactly?

I came here because a friend/client of mine had asked me about converting his boat's twin V8 Crusaders to EFI last summer. We talked again last week and he mentioned that he'd decided against it because someone on RDP told him that you can't convert unless you install O2 sensors, and also he'd read (here) about engine fires. I told him MEFI marine engines don't need them and why. I showed him the Volvo Penta 8.1L in my Regal (MEFI-4; no O2 sensors), we walked over to look at a few others in the marina owned by friends (and my son's 2000 Mercruiser 7.4L MEFI-3) and other MEFI-2s and none of them had O2 sensors. Reading through the first eighty or so posts in this thread I began to understand what scared him off but frankly most of it (starting with needing O2 sensors on wet exhaust engines) was dangerous BS based on a lot of experience here with auto/truck EFI systems. Go back and look at my first post here responding to someone's experience with 1980's vintage Ford 5.0L Mustangs and how he used that experience make a number of wrong conclusions contributing to uninformed recommendations.

There's your answer.

I'm having a hard time believing that, where is the thread

 

[Rajobigguy]

Interesting (and last) thing I'll note before I leave this thread...did anyone here ask you about your "Use Case" i.e. "what problem are you trying to solve?"

On my river high octane marine gas is increasingly hard to find and none of our boats ever go on trailers. There are at least 15 river miles between marina gas docks so we have to deal with everything from 87 to 92 octane on any given day. So the #1 reason to upgrade IMO is to get automatic spark retard/advance from a 'knock sensor' signal feeding a MEFI to enable "Octane Adapt". Some of the newer carbuerated engines have knock-sensors but when you don't, an EFI upgrade is one way to do it (assuming the system has an input for a knock sensor).

Good luck with your decision.

I just put a new carb on it. It doesn't make sense to put any real effort into this particular engine when the supercharged EFI engine that I'm putting together is so close to complete.

 

[rivermobster]

What exactly?

I came here because a friend/client of mine had asked me about converting his boat's twin V8 Crusaders to EFI last summer. We talked again last week and he mentioned that he'd decided against it because someone on RDP told him that you can't convert unless you install O2 sensors, and also he'd read (here) about engine fires. I told him MEFI marine engines don't need them and why. I showed him the Volvo Penta 8.1L in my Regal (MEFI-4; no O2 sensors), we walked over to look at a few others in the marina owned by friends (and my son's 2000 Mercruiser 7.4L MEFI-3) and other MEFI-2s and none of them had O2 sensors. Reading through the first eighty or so posts in this thread I began to understand what scared him off but frankly most of it (starting with needing O2 sensors on wet exhaust engines) was dangerous BS based on a lot of experience here with auto/truck EFI systems. Go back and look at my first post here responding to someone's experience with 1980's vintage Ford 5.0L Mustangs and how he used that experience make a number of wrong conclusions contributing to uninformed recommendations.

There's your answer.

So you're saying you're new to forums, without saying your new to forums?

Every forum I've ever been on has had a selection of different people.

Some talk out there ass, and embarrass themselves, and some have solid knowledge.

Anyone with Working knowledge KNOWS 02 sensors are Mainly for protecting catalytic converters, under a wide range of conditions.

They are Not there for tuning.

Yet, most of us also know all the new bolt on, self learning tuners, pretty much require the addition of them.

We also put one into the CMI's on my buddies Stoker for a piggy back controller installation. Did it work? Hell yeah. No more soot on the transom, way less fuel usage, and the boat did run a touch better.

So from your explanation...

Seems to me you would have been better off educating your friend, rather than inserting yourself in here and trying to prove who's right and who's wrong? Did you forget to answer my question about what your posts say about you?

 

[counterpart7]

Well...I was sure you're not as dumb as that question, but if that's your best effort at a troll maybe I'm wrong?

I bet if I asked you for a performance cam for my kid's '96 SeaDoo Challenger you'd be ready to quote me a price.

Anyone notice the water in the background of this AI generated pic? I was skeptical whether or not it was a bot, but this(and a few other fails) gives me my answer...

 

[Bigbore500r]

Interesting (and last) thing I'll note before I leave this thread...did anyone here ask you about your "Use Case" i.e. "what problem are you trying to solve?"

On my river high octane marine gas is increasingly hard to find and none of our boats ever go on trailers. There are at least 15 river miles between marina gas docks so we have to deal with everything from 87 to 92 octane on any given day. So the #1 reason to upgrade IMO is to get automatic spark retard/advance from a 'knock sensor' signal feeding a MEFI to enable "Octane Adapt". Some of the newer carbuerated engines have knock-sensors but when you don't, an EFI upgrade is one way to do it (assuming the system has an input for a knock sensor).

Good luck with your decision.

Here's a fun one for ya . . .

Since you have now moved on to timing control - how do you think MEFI controls the timing?

 

[counterpart7]

On my 2001 Mercury Marine 496 MAG 8.1L engine I had Raylar just adjust the carburetor and it runs great now!

 

[4Waters]

Anyone notice the water in the background of this AI generated pic? I was skeptical whether or not it was a bot, but this(and a few other fails) gives me my answer...

Yup, zoom in

 

[Bigbore500r]

Well...I was sure you're not as dumb as that question, but if that's your best effort at a troll maybe I'm wrong?

I bet if I asked you for a performance cam for my kid's '96 SeaDoo Challenger you'd be ready to quote me a price.

Minnesota huh? MN numbers . . .

You must be Eric?

ElectroNautical LLC

electronautical.com

 

[ElectroNautical]

Anyone notice the water in the background of this AI generated pic? I was skeptical whether or not it was a bot, but this(and a few other fails) gives me my answer...

 

[Bigbore500r]

I must be on ignore.....pitty

 

[rivermobster]

I must be on ignore.....pitty

You must also be slow today...

Call me when you get a minute? Thanks.

 

[counterpart7]

View attachment 1374186 View attachment 1374185

No way, more pics from the internet! Congrats, the bot learned how to use google...

 

[ElectroNautical]

Here's a fun one for ya . . .

Since you have now moved on to timing control - how do you think MEFI controls the timing?

Already asked, already answered. Look up in the thread for "Base Map", "Knock Sensor" and "Octane Adapt", or if you need help click here.

View attachment 1374174 View attachment 1374175

 

[Bigbore500r]

Already asked, already answered. Look up in the thread for "Base Map", "Knock Sensor" and "Octane Adapt", or if you need help click here.

It uses a table Eric. A table.
The entire computer references tables….

Table.

 

[4Waters]

Already asked, already answered. Look up in the thread for "Base Map", "Knock Sensor" and "Octane Adapt", or if you need help click here.

Did you find the thread yet?

 

[Racey]

It uses a table Eric. A table.
The entire computer references tables….

Table.

Would you say the values in these tables are "looked up"?

Who needs an O2 sensor whe the mefi can learn from the knock sensor? You don't need to tune any of those tables just pet it ping and the Mefi self learns

 

[ElectroNautical]

It uses a table Eric. A table.
The entire computer references tables….

Table.

So Jerry, tell me where the Octane table is? Do you modify that table every time you fill up?

 

[mattyc]

What exactly?

I came here because a friend/client of mine had asked me about converting his boat's twin V8 Crusaders to EFI last summer. We talked again last week and he mentioned that he'd decided against it because someone on RDP told him that you can't convert unless you install O2 sensors, and also he'd read (here) about engine fires. I told him MEFI marine engines don't need them and why. I showed him the Volvo Penta 8.1L in my Regal (MEFI-4; no O2 sensors), we walked over to look at a few others in the marina owned by friends (and my son's 2000 Mercruiser 7.4L MEFI-3) and other MEFI-2s and none of them had O2 sensors. Reading through the first eighty or so posts in this thread I began to understand what scared him off but frankly most of it (starting with needing O2 sensors on wet exhaust engines) was dangerous BS based on a lot of experience here with auto/truck EFI systems. Go back and look at my first post here responding to someone's experience with 1980's vintage Ford 5.0L Mustangs and how he used that experience make a number of wrong conclusions contributing to uninformed recommendations.

There's your answer.

The original post was asking about sniper efi, a holley product, not mefi. All the examples you just stated were factory offerings that were designed and engineered without o2 sensors and NOT a conversion like your friend / client was inquiring about. Apples and oranges.

 

[Racey]

The original post was asking about sniper efi, a holley product, not mefi. All the examples you just stated were factory offerings that were designed and engineered without o2 sensors and NOT a conversion like your friend / client was inquiring about. Apples and oranges.

And they had extensive dyno tuning with O2 sensors and then those engine packages are finalized and the tune/calibration is locked to work with that specific configuration.

O2 sensors are not needed to run the motor. But they are extremely helpful in safely tuning one in the first place.

 

[mattyc]

And they had extensive dyno tuning with O2 sensors and then those engine packages are finalized and the tune/calibration is locked to work with that specific configuration.

O2 sensors are not needed to run the motor. But they are extremely helpful in safely tuning one in the first place.

A saying comes to mind, something about a nail and a head?

 

[ElectroNautical]

The original post was asking about sniper efi, a holley product, not mefi. All the examples you just stated were factory offerings that were designed and engineered without o2 sensors and NOT a conversion like your friend / client was inquiring about. Apples and oranges.

Yes, that's right. But I only introduced MEFI to illustrate the example of a Marine EFI system that did not use or need O2 sensors. And OBTW Holley certainly DOES operate (in 'open loop' mode) without them.

 

[Bigbore500r]

Would you say the values in these tables are "looked up"?

Who needs an O2 sensor whe the mefi can learn from the knock sensor? You don't need to tune any of those tables just pet it ping and the Mefi self learns

Yes, just let it rip free like the wind! Things will work themself out just fine

 

[Bigbore500r]

So Jerry, tell me where the Octane table is? Do you modify that table every time you fill up?

No, but riddle me this oh mysterious one - where does your MEFI get its spark advance values from? A crystal ball? Jesus? It uses a table, just like when it determines fueling .

You’re gonna dig this hole to China …. Unfortunately you’ll discover they use tables in their EFI programs too

 

[ElectroNautical]

Minnesota huh? MN numbers . . .

You must be Eric?

ElectroNautical LLC

electronautical.com

Bingo Mr. Hovet! After all this, you win the prize!

 

[Bigbore500r]

So Jerry, tell me where the Octane table is? Do you modify that table every time you fill up

No need to - because REGARDLESS of what fuel you put in, the ECM reads the spark advance table (yes…another table) and sets timing based on the numeric value shown in that cell for load and rpm.

If it is equipped with knock sensors and detects knock, it will then….well, your not gonna believe this but…..IT WILL THEN REFERENCE A TABLE for knock retard values to apply for that cell for load and RPM.

You’re gonna dig this hole to China aren’t ya …. Unfortunately when you get there, you’ll discover they use tables in their EFI programs too….

Table for 2 please!

 

[ElectroNautical]

It uses a table Eric. A table.
The entire computer references tables….

Table.

Yes Jerry, a base map is visually represented as a table, which is why you are confused. A 'Look-up Table' is a different thing with a different purpose. This also has been explained above.

Maybe this will help. When you do your taxes, you might use a "Look-up Table" but if you are smart enough to do the math (or have a calculator) you will pay less if you actually do the math and multiply for yourself.

Tax "Look-Up Tables" https://www.irs.gov/instructions/i1040tt

 

[Bigbore500r]

Bingo Mr. Hovet! After all this, you win the prize!

I hope the prize is you coming to the realization that EFI (all types, even MEFI) use tables.

If it’s not - I’ll just take a gift card to Applebees I guess

 

[Bigbore500r]

Yes Jerry, a base map is visually represented as a table, which is why you are confused. A 'Look-up Table' is a different thing with a different purpose. This also has been explained above.

Maybe this will help. When you do your taxes, you might use a "Look-up Table" but if you are smart enough to do the math (or have a calculator) you will pay less if you actually do the math and multiply for yourself.

Tax "Look-Up Tables" https://www.irs.gov/instructions/i1040tt

Holy shit…..your finally backpedaling after 10 pages and coming around!

The ECM uses tables! Tables that you can’t see in your basic diagnostic software!

Step one is admitting your condition. Step 2 is working to improve it. Good job!

 

[DaveH]

So if it's your last post why does it end with a simplistic (and insulting) question? Answering you would either be insulting you OR playing the 'game' you accuse me of right?

So...re: "how many times does each injector driver fire the injector for a MEFI 4 at 6000rpm?" You might as well be asking "how many quarts-per-gallon go over Niagara Falls every hour?" I'd say your questions are far more insulting than my answers, like @Racey asking me "OK smarty, how do you tune air-fuel ratios on a diesel".

Insulting questions like that should will not be dignified with an answer. Thanks for playing. Game over.

actually knowing how many time an injection event happens for a given RPM is very basic math....if you are into this stuff which you claim to be. and its important too, especially with a MEFI1-4.

ill wait for your answer.

 

[ElectroNautical]

Yes Jerry, a base map is visually represented as a table, which is why you are confused. A 'Look-up Table' is a different thing with a different purpose. This also has been explained above.

Maybe this will help. When you do your taxes, you might use a "Look-up Table" but if you are smart enough to do the math (or have a calculator) you will pay less if you actually do the math and multiply for yourself.

Tax "Look-Up Tables" https://www.irs.gov/instructions/i1040tt

Since we all know I'm not a bot now (thanks to Jerry Hovet's research) I can show my Electrical Engineer's chops and provide ya'll another example from ABYC.

If you use the 'base map' tables from ABYC E-11 to choose the gauge and insulation temperature rating of boat wiring, you will be wasting money 90% of the time, but the calculations you need to do compute an economically optimal gauge of wire are beyond the capabilities of electricians who are not electrical engineers. The tables in ABYC E-11 are safe 'starting values' but almost always result in oversized wiring.

Anybody want to see the tables and/or the calculations that can be used to save money on copper? Copper has gotten REALLY expensive lately...

 

[Bigbore500r]

Since we all know I'm not a bot now (thanks to Jerry Hovet's research) I can show my Electrical Engineer's chops and provide ya'll another example from ABYC.

If you use the 'base map' tables from ABYC E-11 to choose the gauge and insulation temperature rating of boat wiring, you will be wasting money 90% of the time, but the calculations you need to do compute an economically optimal gauge of wire are beyond the capabilities of electricians who are not electrical engineers. The tables in ABYC E-11 are safe 'starting values' but almost always result in oversized wiring.

Anybody want to see the tables and/or the calculations that can be used to save money on copper? Copper has gotten REALLY expensive lately...

Why don’t you answer the question your being asked…..how many times does MEFI fire a single cylinder’s fuel injector at 6000rpm?

 

[DaveH]

yes please post your rule of thumb for a given load and length of run.

Since we all know I'm not a bot now (thanks to Jerry Hovet's research) I can show my Electrical Engineer's chops and provide ya'll another example from ABYC.

If you use the 'base map' tables from ABYC E-11 to choose the gauge and insulation temperature rating of boat wiring, you will be wasting money 90% of the time, but the calculations you need to do compute an economically optimal gauge of wire are beyond the capabilities of electricians who are not electrical engineers. The tables in ABYC E-11 are safe 'starting values' but almost always result in oversized wiring.

Anybody want to see the tables and/or the calculations that can be used to save money on copper? Copper has gotten REALLY expensive lately...

 

[counterpart7]

Hi Eric
Your website is worse than your understanding of MEFI. Also, it's riddled with spelling errors.

 

[Racey]

Yes Jerry, a base map is visually represented as a table, which is why you are confused. A 'Look-up Table' is a different thing with a different purpose. This also has been explained above.

Maybe this will help. When you do your taxes, you might use a "Look-up Table" but if you are smart enough to do the math (or have a calculator) you will pay less if you actually do the math and multiply for yourself.

Tax "Look-Up Tables" https://www.irs.gov/instructions/i1040tt

Lol, no a look up table is exactly what bigbore states, it's used because there is no amount of mathematical modeling a mefi can do to perfectly,.or even remotely select the proper fueling.

The table is used to fill in values in place of some gigantic formula that wouldn't work because sensor data isn't a perfect representation of the mass of air injested or the general efficiency of the engine. and also the mefi does not have the ability to know the fuel mass data either as there are many variables there that need to be accounted for on the fuel side as well.

The processing power of a mefi IC isn't that great on top of all this as well. Look up tables save massive amounts of processing time and also give the end user the ability to account for conditions that fall outside the boundary of a "theory of everything" equation thay doesn't exist anyway.