Sniper EFI for boat.

[Racey]

Here is something you will have a hard time comprehending:

 

[counterpart7]

Holy shit bots are getting impressive… kinda scary

 

[Rajobigguy]

Resolution: The rules say (1) a member (not the owner) will hold the bet. Consistent with the rules, I nominate the OP @Rajobigguy, and will accept any amount he's comfortable with, as long as he (or any other non-affiliated MEMBER on this site) can demonstrate an understanding of what a "Look-Up-Table" is. The criteria for demonstrating understanding will be the identification of the five-letter humorous acronym used to describe the function of a look-up table by the inventor circa 1960.

Weasle #2: Talking your way down to a $1 bet? LoL...hardly worth my time. Nice try. I would think your reputation here is worth more than that.

Resolution: Let's use your $10K number as a start, but as you knew before suggesting it, nobody without a vested interest is going to bite on escrowing that much.

Weasle #3 You already know that GM/Delphi has published (in dealer-confidential documents) the details needed to modify MEFI parameters, and I am putting 566 pages into evidence, right here, right now. I guarantee that document will provide all the details proving that there are no "Look-up-Tables" in any GM MEFI system.

Last comment...nothing you posted above (screenshots, etc.) has anything to do with a "Look-Up-Table". You are confusing MEFI PARAMETERS presented in a TABULAR FORMAT with "LOOK UP TABLE VALUES".

This explains your problems comprehending. You simply don't know the meaning or function of a "LOOK UP TABLE".

So, my evidence is uploaded to the cloud HERE. Bring it on Racey, let's get on with the bet.

Just because I asked if anyone had any input on Snipper (and similar throttle body’s) on boats doesn’t mean that I’m not familiar with EFI systems. I fully understand the differences between speed density and mass airflow. I also understand fuel maps and look up tables . The thing is I doubt that you would want me to make judgments because you are wrong. It appears that you have read the instructions but never did a deep dive into the programming.

 

[Bigbore500r]

Embrace AI they said…..it will be fun they said……

 

[4Waters]

Embrace AI they said…..it will be fun they said……

I was troubleshooting my security cameras with AI and I typed "AI is stupid" or something like that because it couldn't comprehend my question. Anyway it responded "Bots have feelings too and that hurt them"

 

[rivermobster]

It's like ChatGPT, LOF and Grads had a threesome.

Probably the best post in the thread...

 

[RiverDave]

Holy shit bots are getting impressive… kinda scary

I don’t think this is an ai bot..

 

[rivermobster]

I don’t think this is an ai bot..

I think it's someone who took a vocational training class, back in 2005, saved the training book, and now knows everything everything about EFI, from reading that ONE book, every night, before he went to sleep!

Maybe his dad is a TV repair man, and has an Awesome set of tools?

 

[Bigbore500r]

I don’t think this is an ai bot..

Whatever it is, it runs in real time without lookup tables…

 

[Rajobigguy]

Whatever it is, it runs in real time without lookup tables…

And has a MAP sensor so you can just Jack the fuel pressure up and it automatically corrects the fuel map and injector duty cycle.

 

[mash on it]

And has a MAP sensor so you can just Jack the fuel pressure up and it automatically corrects the fuel map and injector duty cycle.

Old school Cummins drivers had vice grips and dimes, so there's that.

Dan'l

 

[ElectroNautical]

Just because I asked if anyone had any input on Snipper Sniper (and similar throttle body’s bodies) on boats doesn’t mean that I’m not familiar with EFI systems. I fully understand the differences between speed density and mass airflow. I also understand fuel maps and look up tables . The thing is I doubt that you would want me to make judgments because you are wrong. It appears that you have read the instructions but never did a deep dive into the programming.

No, sorry...I've programmed more look-up-tables than everyone here combined, starting back in the day when we used visicalc on an Apple II to do the math.

A few years back my son told a story about a girl in his computer science class who got in the professors face and said she had proof that the Apollo Moon Missions (and the moon landing) were all a hoax. The 'evidence' she provided as 'proof' was that the computer in the LEM (codename "Luminary") was no where near powerful enough to perform the mathmatical calculations needed to determine fuel flow to the engine throughout the decent phase and that Luminary099 was so weak it could not even calculate the value of PI. She was right about that but showed off her ignorance in the process.

The professor (a retired aerospace engineer) responded "Of course it couldn't...it didn't even try because it couldn't, and didn't need to. The values needed were calculated in advance here on earth using Mainframe computers and the results merely stored as Look-Up-Tables in the code that went to the moon...". Now she knows what IBM (inventor of Look-Up-Table indexing) acronym CADET stands for...Can't Add Don't Even Try.

In the Marine world, beginning with MEFI-1, there are no pre-calculated, stored values that are "looked-up" to determine what the injector pulse widths will be ONCE THE ENGINE IS RUNNING, what the spark-advance will be ONCE THE ENGINE IS RUNNING, or even what the VE of the engine is ONCE THE ENGINE IS RUNNING and ACTUALLY PUMPING AIR. As soon as the sensors come online (typically in seconds or milliseconds) the base map goes out the window and MEFI tunes EVERYTHING. MEFI can do this because it does floating-point math millions of times faster than the earliest EFI systems could and infinitely faster than Luminary099, which could do exactly ZERO FLOPs.

The first mistake you and Shane are making is confusing a MEFI configurable "Parameter" (like rev limit) with a 'Tuning', and all your subsequent errors stem from there.

An engine might be modified with a valve train that allows it to run at higher RPM, so one might change the Rev Limit PARAMETER to increase the operational envelope and allow higher RPMs, but that is not a 'tuning'. A MEFI Vortec 8100 might be mechanically modified (by Raylar, for example) from stock 375HP to 520HP such that it can inhale more air...and then needs more fuel than the mysteriously GM-downrated 42PSI regulator will allow, and so putting the fuel rail pressure regulator back to 60PSI is needed, but this is also not 'tuning', it is merely done to make more fuel available match the increased air available. MEFI does ALL the tuning math in REAL TIME.

The second mistake you are making is confusing a 'Base Map' with a "Look-up-Table". In MEFI, the 'Base Map' is only ever used ONCE -- when an engine is first started and run, and then it is ignored as the MEFI controller takes over and does ALL the tuning in REAL TIME. A MEFI configuration file has BASE MAPS including initial PARAMETERS for spark advance, injector pulse widths, and any other things the system can't know until the engine is actually RUNNING. As soon as the engine is running, MEFI starts tuning EVERYTHING. Spark advance is increased or decreased depending on the output from the Knock Sensor, injector pulse widths are changed based on MAP (vacuum), BARO, RPM, IAT, ECT and in MEFI-5 and above, even fuel temperature (if the engine remarketer chooses). Once MEFI has figured out the 'tuning', it will continue using the values it calculated and the 'dumb' Base Map is never seen again.

Bob LLoyd at Full Throttle Marine has one of the very few 800HP prop-shaft dynamometers out there and I can tell you've never seen (or heard) one. I could describe the sound these things make if I thought you'd believe it, but I'm not going to 'cure' either of you.

"The difference between ignorance and stupidity is one of them is curable." Frank Zappa; quoted in "The Negative Dialectics of Poodle Play" 1996

https://www.riverdavesplace.com/forums/threads/nordic-rage-with-raylar-525-ho.128627/

Vortec 8100 / 8.1L / 496MAG Mercury Marine Performance Parts Upgrade - Raylar Big Power

Vortec 8100 / 8.1L / 496mag mercury marine performance parts upgrades.

www.raylarengineering.com

"Full Throttle Marine" "lloyd" "raylar" - Google Search

www.google.com

 

[Eliminator21vdrive]

HOLEESHIT! SMH! It still has to know what it needs to be.

 

[ElectroNautical]

No, sorry...I've programmed more look-up-tables than everyone here combined, starting back in the day when we used visicalc on an Apple II to do the math.

A few years back my son told a story about a girl in his computer science class who got in the professors face and said she had proof that the Apollo Moon Missions (and the moon landing) were all a hoax. The 'evidence' she provided as 'proof' was that the computer in the LEM (codename "Luminary") was no where near powerful enough to perform the mathmatical calculations needed to determine fuel flow to the engine throughout the decent phase and that Luminary099 was so weak it could not even calculate the value of PI. She was right about that but showed off her ignorance in the process.

The professor (a retired aerospace engineer) responded "Of course it couldn't...it didn't even try because it couldn't, and didn't need to. The values needed were calculated in advance here on earth using Mainframe computers and the results merely stored as Look-Up-Tables in the code that went to the moon...". Now she knows what IBM (inventor of Look-Up-Table indexing) acronym CADET stands for...Can't Add Don't Even Try.

In the Marine world, beginning with MEFI-1, there are no pre-calculated, stored values that are "looked-up" to determine what the injector pulse widths will be ONCE THE ENGINE IS RUNNING, what the spark-advance will be ONCE THE ENGINE IS RUNNING, or even what the VE of the engine is ONCE THE ENGINE IS RUNNING and ACTUALLY PUMPING AIR. As soon as the sensors come online (typically in seconds or milliseconds) the base map goes out the window and MEFI tunes EVERYTHING. MEFI can do this because it does floating-point math millions of times faster than the earliest EFI systems could and infinitely faster than Luminary099, which could do exactly ZERO FLOPs.

The first mistake you and Shane are making is confusing a MEFI configurable "Parameter" (like rev limit) with a 'Tuning', and all your subsequent errors stem from there.

An engine might be modified with a valve train that allows it to run at higher RPM, so one might change the Rev Limit PARAMETER to increase the operational envelope and allow higher RPMs, but that is not a 'tuning'. A MEFI Vortec 8100 might be mechanically modified (by Raylar, for example) from stock 375HP to 520HP such that it can inhale more air...and then needs more fuel than the mysteriously GM-downrated 42PSI regulator will allow, and so putting the fuel rail pressure regulator back to 60PSI is needed, but this is also not 'tuning', it is merely done to make more fuel available match the increased air available. MEFI does ALL the tuning math in REAL TIME.

View attachment 1374002

The second mistake you are making is confusing a 'Base Map' with a "Look-up-Table". In MEFI, the 'Base Map' is only ever used ONCE -- when an engine is first started and run, and then it is ignored as the MEFI controller takes over and does ALL the tuning in REAL TIME. A MEFI configuration file has BASE MAPS including initial PARAMETERS for spark advance, injector pulse widths, and any other things the system can't know until the engine is actually RUNNING. As soon as the engine is running, MEFI starts tuning EVERYTHING. Spark advance is increased or decreased depending on the output from the Knock Sensor, injector pulse widths are changed based on MAP (vacuum), BARO, RPM, IAT, ECT and in MEFI-5 and above, even fuel temperature (if the engine remarketer chooses). Once MEFI has figured out the 'tuning', it will continue using the values it calculated and the 'dumb' Base Map is never seen again.

Bob LLoyd at Full Throttle Marine has one of the very few 800HP prop-shaft dynamometers out there and I can tell you've never seen (or heard) one. I could describe the sound these things make if I thought you'd believe it, but I'm not going to 'cure' either of you.

"The difference between ignorance and stupidity is one of them is curable." Frank Zappa; quoted in "The Negative Dialectics of Poodle Play" 1996

https://www.riverdavesplace.com/forums/threads/nordic-rage-with-raylar-525-ho.128627/

Vortec 8100 / 8.1L / 496MAG Mercury Marine Performance Parts Upgrade - Raylar Big Power

Vortec 8100 / 8.1L / 496mag mercury marine performance parts upgrades.

www.raylarengineering.com

"Full Throttle Marine" "lloyd" "raylar" - Google Search

www.google.com

Re: "...but never did a deep dive into the programming." LoL. And you have? Can you even name the programming language that was used to take advantage of the first (mid-1970's) commercially available computers that could actually do floating-point math? I've written 10's of thousands of lines of code in that language. If you knew anything, you'd at least know that.

 

[ElectroNautical]

HOLEESHIT! SMH! It still has to know what it needs to be.

Yes...it's called "doing the math" and "computing the answer"...

 

[ElectroNautical]

Holy shit bots are getting impressive… kinda scary

Ever hear of a little thing called the "Turing Test"? No? Not surprised...

 

[ElectroNautical]

Yes...it's called "doing the math" and "computing the answer"... View attachment 1374036

So, anyone here getting it? Just for fun, here is the code from Luminary099 that had to bring PI along with it from Earth because it could not do the math. And LOL...the value of PI here is actually incorrect! Who can spot the error?

 

[Runs2rch]

So, anyone here getting it? Just for fun, here is the code from Luminary099 that had to bring PI along with it from Earth because it could not do the math. And LOL...the value of PI here is actually incorrect! Who can spot the error?

You still here?!

 

[ElectroNautical]

Good job @DaveH and @Racey running off our EFI bot

Or maybe not so much? Mindless syncophantic minions are not in short supply here. Neither are stupid laughing emoticons.

 

[ElectroNautical]

You still here?!

Yes, some of us are off enjoying our boats on beautiful weekends instead of making stupid comments about stuff they can't comprehend and punctuating them with even stupider emoticons.

Hint: multiple identical emoticons doesn't make you seem funnier or smarter...

 

[Runs2rch]

Or maybe not so much? Mindless syncophantic minions are not in short supply here. Neither are stupid laughing emoticons.

 

[ElectroNautical]

Thanks!

"Eat shit, billions of flies can't all be wrong..."
Marshall McLuhan (apocryphal)

 

[Blackmagic94]

Ever hear of a little thing called the "Turing Test"? No? Not surprised...

Please upload a picture of you with a sign saying RDPsux.

 

[ElectroNautical]

I don’t think this is an ai bot..

Hi RiverDave, I'm enjoying my stay here at your place! I expect it will be short, but in the meantime please don't expose me and spoil the fun. Among my critics here I've got half of them thinking I'm ChatGPT on WOKE, and the other half identifying me as 'turd brain', 'libtard', 'libturd', 'Biden voter', 'Clown', etc. etc. and they're all trying, flailing and still failing to get it right...

"The question is...is an artificial intelligence machine better than a pseudo-intelligent human?"
-Unattributed.

 

[FreeBird236]

Hi RiverDave, I'm enjoying my stay here at your place! I expect it will be short, but in the meantime please don't expose me and spoil the fun. Among my critics here I've got half of them thinking I'm ChatGPT on WOKE, and the other half identifying me as 'turd brain', 'libtard', 'libturd', 'Biden voter', 'Clown', etc. etc. and they're all trying, flailing and still failing to get it right...

"The question is...is an artificial intelligence machine better than a pseudo-intelligent human?"
-Unattributed.

Are you New To Boating by any chance?

 

[Rajobigguy]

No, sorry...I've programmed more look-up-tables than everyone here combined, starting back in the day when we used visicalc on an Apple II to do the math.

A few years back my son told a story about a girl in his computer science class who got in the professors face and said she had proof that the Apollo Moon Missions (and the moon landing) were all a hoax. The 'evidence' she provided as 'proof' was that the computer in the LEM (codename "Luminary") was no where near powerful enough to perform the mathmatical calculations needed to determine fuel flow to the engine throughout the decent phase and that Luminary099 was so weak it could not even calculate the value of PI. She was right about that but showed off her ignorance in the process.

The professor (a retired aerospace engineer) responded "Of course it couldn't...it didn't even try because it couldn't, and didn't need to. The values needed were calculated in advance here on earth using Mainframe computers and the results merely stored as Look-Up-Tables in the code that went to the moon...". Now she knows what IBM (inventor of Look-Up-Table indexing) acronym CADET stands for...Can't Add Don't Even Try.

In the Marine world, beginning with MEFI-1, there are no pre-calculated, stored values that are "looked-up" to determine what the injector pulse widths will be ONCE THE ENGINE IS RUNNING, what the spark-advance will be ONCE THE ENGINE IS RUNNING, or even what the VE of the engine is ONCE THE ENGINE IS RUNNING and ACTUALLY PUMPING AIR. As soon as the sensors come online (typically in seconds or milliseconds) the base map goes out the window and MEFI tunes EVERYTHING. MEFI can do this because it does floating-point math millions of times faster than the earliest EFI systems could and infinitely faster than Luminary099, which could do exactly ZERO FLOPs.

The first mistake you and Shane are making is confusing a MEFI configurable "Parameter" (like rev limit) with a 'Tuning', and all your subsequent errors stem from there.

An engine might be modified with a valve train that allows it to run at higher RPM, so one might change the Rev Limit PARAMETER to increase the operational envelope and allow higher RPMs, but that is not a 'tuning'. A MEFI Vortec 8100 might be mechanically modified (by Raylar, for example) from stock 375HP to 520HP such that it can inhale more air...and then needs more fuel than the mysteriously GM-downrated 42PSI regulator will allow, and so putting the fuel rail pressure regulator back to 60PSI is needed, but this is also not 'tuning', it is merely done to make more fuel available match the increased air available. MEFI does ALL the tuning math in REAL TIME.

View attachment 1374002

The second mistake you are making is confusing a 'Base Map' with a "Look-up-Table". In MEFI, the 'Base Map' is only ever used ONCE -- when an engine is first started and run, and then it is ignored as the MEFI controller takes over and does ALL the tuning in REAL TIME. A MEFI configuration file has BASE MAPS including initial PARAMETERS for spark advance, injector pulse widths, and any other things the system can't know until the engine is actually RUNNING. As soon as the engine is running, MEFI starts tuning EVERYTHING. Spark advance is increased or decreased depending on the output from the Knock Sensor, injector pulse widths are changed based on MAP (vacuum), BARO, RPM, IAT, ECT and in MEFI-5 and above, even fuel temperature (if the engine remarketer chooses). Once MEFI has figured out the 'tuning', it will continue using the values it calculated and the 'dumb' Base Map is never seen again.

Bob LLoyd at Full Throttle Marine has one of the very few 800HP prop-shaft dynamometers out there and I can tell you've never seen (or heard) one. I could describe the sound these things make if I thought you'd believe it, but I'm not going to 'cure' either of you.

"The difference between ignorance and stupidity is one of them is curable." Frank Zappa; quoted in "The Negative Dialectics of Poodle Play" 1996

https://www.riverdavesplace.com/forums/threads/nordic-rage-with-raylar-525-ho.128627/

Vortec 8100 / 8.1L / 496MAG Mercury Marine Performance Parts Upgrade - Raylar Big Power

Vortec 8100 / 8.1L / 496mag mercury marine performance parts upgrades.

www.raylarengineering.com

"Full Throttle Marine" "lloyd" "raylar" - Google Search

www.google.com

I think I have it figured out. This must be a Camala Harris chat bot. It’s the only thing that would explain the meaning less word salad that it comes up with.

 

[ElectroNautical]

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

they arent cooling the fuel to cool the injectors, its to combat vapor lock.

marine engines run wayyyyyy cooler then their automotive counterparts, yet those pesky "automotive" injectors seem to do just fine well north of 200' and no fuel cooling.

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.

 

[ElectroNautical]

Are you New To Boating by any chance?

LoL...I qualified for OUPV (Captains License) by age 16 on a Graymarine V8 powered 1964 Chris Craft Cavalier that was only five years old when I was running it on the rivers, lakes and canals of upstate and Western New York. Since then my boats have been bigger and newer every year. Does that answer your question?

 

[ElectroNautical]

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

And lastly...duty cycle is proportional to RPMs. A boat up on plane is often running at 3,500 RPM for hours at a time. When was the last time you saw any auto or truck engine run at a continuous 3,500 RPM for more than a minute or two? Even climbing the steepest, longest hill you can think of towing at maximum rated capacity, you'll never see 3,500 RPM for HOURS at a time.

 

[Racey]

No, sorry...I've programmed more look-up-tables than everyone here combined, starting back in the day when we used visicalc on an Apple II to do the math.

A few years back my son told a story about a girl in his computer science class who got in the professors face and said she had proof that the Apollo Moon Missions (and the moon landing) were all a hoax. The 'evidence' she provided as 'proof' was that the computer in the LEM (codename "Luminary") was no where near powerful enough to perform the mathmatical calculations needed to determine fuel flow to the engine throughout the decent phase and that Luminary099 was so weak it could not even calculate the value of PI. She was right about that but showed off her ignorance in the process.

The professor (a retired aerospace engineer) responded "Of course it couldn't...it didn't even try because it couldn't, and didn't need to. The values needed were calculated in advance here on earth using Mainframe computers and the results merely stored as Look-Up-Tables in the code that went to the moon...". Now she knows what IBM (inventor of Look-Up-Table indexing) acronym CADET stands for...Can't Add Don't Even Try.

In the Marine world, beginning with MEFI-1, there are no pre-calculated, stored values that are "looked-up" to determine what the injector pulse widths will be ONCE THE ENGINE IS RUNNING, what the spark-advance will be ONCE THE ENGINE IS RUNNING, or even what the VE of the engine is ONCE THE ENGINE IS RUNNING and ACTUALLY PUMPING AIR. As soon as the sensors come online (typically in seconds or milliseconds) the base map goes out the window and MEFI tunes EVERYTHING. MEFI can do this because it does floating-point math millions of times faster than the earliest EFI systems could and infinitely faster than Luminary099, which could do exactly ZERO FLOPs.

The first mistake you and Shane are making is confusing a MEFI configurable "Parameter" (like rev limit) with a 'Tuning', and all your subsequent errors stem from there.

An engine might be modified with a valve train that allows it to run at higher RPM, so one might change the Rev Limit PARAMETER to increase the operational envelope and allow higher RPMs, but that is not a 'tuning'. A MEFI Vortec 8100 might be mechanically modified (by Raylar, for example) from stock 375HP to 520HP such that it can inhale more air...and then needs more fuel than the mysteriously GM-downrated 42PSI regulator will allow, and so putting the fuel rail pressure regulator back to 60PSI is needed, but this is also not 'tuning', it is merely done to make more fuel available match the increased air available. MEFI does ALL the tuning math in REAL TIME.

View attachment 1374002

The second mistake you are making is confusing a 'Base Map' with a "Look-up-Table". In MEFI, the 'Base Map' is only ever used ONCE -- when an engine is first started and run, and then it is ignored as the MEFI controller takes over and does ALL the tuning in REAL TIME. A MEFI configuration file has BASE MAPS including initial PARAMETERS for spark advance, injector pulse widths, and any other things the system can't know until the engine is actually RUNNING. As soon as the engine is running, MEFI starts tuning EVERYTHING. Spark advance is increased or decreased depending on the output from the Knock Sensor, injector pulse widths are changed based on MAP (vacuum), BARO, RPM, IAT, ECT and in MEFI-5 and above, even fuel temperature (if the engine remarketer chooses). Once MEFI has figured out the 'tuning', it will continue using the values it calculated and the 'dumb' Base Map is never seen again.

Bob LLoyd at Full Throttle Marine has one of the very few 800HP prop-shaft dynamometers out there and I can tell you've never seen (or heard) one. I could describe the sound these things make if I thought you'd believe it, but I'm not going to 'cure' either of you.

"The difference between ignorance and stupidity is one of them is curable." Frank Zappa; quoted in "The Negative Dialectics of Poodle Play" 1996

https://www.riverdavesplace.com/forums/threads/nordic-rage-with-raylar-525-ho.128627/

Vortec 8100 / 8.1L / 496MAG Mercury Marine Performance Parts Upgrade - Raylar Big Power

Vortec 8100 / 8.1L / 496mag mercury marine performance parts upgrades.

www.raylarengineering.com

"Full Throttle Marine" "lloyd" "raylar" - Google Search

www.google.com

Lol this is absolutely pure garbage and almost completely incorrect

I guess all of that have tuned hundreds of mefi fuel tables were pissing in the wind

 

[ElectroNautical]

Here is something you will have a hard time comprehending:

Your problem is that as your daddy's apprentice race-engine machinist you've been so fascinated by shiny spinning bits of metal that you can get up to (maybe) 10,000 RPM that you never bothered to learn about the silicon bits that are 'spinning' at clock speeds 100 million times faster. I bet if we put you in front of a turntable spinning vinyl at 33.333... rpm you'd have a hard time taking your eyes off of it ;-)

 

[Racey]

Your problem is that as your daddy's apprentice race-engine machinist you've been so fascinated by shiny spinning bits of metal that you can get up to (maybe) 10,000 RPM that you never bothered to learn about the silicon bits that are 'spinning' at clock speeds 100 million times faster. I bet if we put you in front of a turntable spinning vinyl at 33.333... rpm you'd have a hard time taking your eyes off of it ;-)

You obviously know about as much about my career as you do about MEFI boxes.

 

[ElectroNautical]

I guess all of that have tuned hundreds of mefi fuel tables were pissing in the wind

Yes, if you were 'tuning' any fuel tables for any Marine MEFI-1 through MEFI-7 (or above), you were only "tuning" the BASE MAP and that's the same thing as 'pissing in the wind'.

 

[Racey]

Yes, if you were 'tuning' any fuel tables for any Marine MEFI-1 through MEFI-7 (or above), you were only "tuning" the BASE MAP and that's the same thing as 'pissing in the wind'.

Its obvious you don't understand what the 'base' means in 'base pulse width'

 

[FreeBird236]

LoL...I qualified for OUPV (Captains License) by age 16 on a Graymarine V8 powered 1964 Chris Craft Cavalier that was only five years old when I was running it on the rivers, lakes and canals of upstate and Western New York. Since then my boats have been bigger and newer every year. Does that answer your question?

Yes. I guess you're not, something just seemed familiar.

 

[ElectroNautical]

Please upload a picture of you with a sign saying RDPsux.

Why would I do that? I love it here. It's a 'Target Rich Environment' and as much fun as shooting fish in a barrel...

 

[ElectroNautical]

Its obvious you don't understand what the 'base' means in 'base pulse width'

Funny thing, since you're such a BMOC here I'd have thought you'd have some kind of presence on performanceboats.com. You don't have a great reputation there, maybe that's why you hang out here. Here's your chance to shine. Post a reply to this post and see how fast you get your ass laughed off the site. 40,000 plus members there and I'm sure you'll have a great time...

Mercruiser 496 MPI tuning for engine mods

www.performanceboats.com

 

[ElectroNautical]

Lol this is absolutely pure garbage and almost completely incorrect

Re: "almost completely incorrect..." Show your work, laughing boy. What exactly is 'completely incorrect'? Im'a keep feeding you rope and you're gonna hang yourself with it.

 

[rivrrts429]

Funny thing, since you're such a BMOC here I'd have thought you'd have some kind of presence on performanceboats.com. You don't have a great reputation there, maybe that's why you hang out here. Here's your chance to shine. Post a reply to this post and see how fast you get your ass laughed off the site. 40,000 plus members there and I'm sure you'll have a great time...

Mercruiser 496 MPI tuning for engine mods

www.performanceboats.com

That site is dead. That thread link you posted is from almost a year ago. It’s about to have a birthday and nobody has ever replied.

40k members but the site moves at a snails pace?

It would take a year or more for someone to reply to “laugh” someone off that forum lol

 

[ElectroNautical]

I think I have it figured out. This must be a Camala Kamala Harris chat bot. It’s the only thing that would explain the meaning less meaningless word salad that it comes up with.

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

 

[Racey]

Re: "almost completely incorrect..." Show your work, laughing boy. What exactly is 'completely incorrect'? Im'a keep feeding you rope and you're gonna hang yourself with it.

View attachment 1374085

The apollo stuff you weren't wrong about

The MEFI stuff, you obviously have never used it, don't know how it works. You read some books and mistook their block diagrams showing you logic procedure for actually being a math function completely independent from look up data.

 

[ElectroNautical]

That site is dead. That thread link you posted is from almost a year ago. It’s about to have a birthday and nobody has ever replied.

40k members but the site moves at a snails pace?

It would take a year or more for someone to reply to “laugh” someone off that forum lol

No, the site is bigger and more active than this one. All of the big engine builders are there (not here). That post has no replies because it was a stupid silly question and people there tend to be kind to newbies who ask them.

 

[Racey]

No, the site is bigger and more active than this one. All of the big engine builders are there (not here). That post has no replies because it was a stupid silly question and people there tend to be kind to newbies who ask them.

View attachment 1374088

More popular. Newest post is from 5 hours ago, next is 14h ago.... Pack it up boys!

 

[rivrrts429]

No, the site is bigger and more active than this one. All of the big engine builders are there (not here). That post has no replies because it was a stupid silly question and people there tend to be kind to newbies who ask them.

View attachment 1374088

I’ll take your word for it but the analytics say otherwise, it’s slow.

 

[ElectroNautical]

I’ll take your word for it but the analytics say otherwise, it’s slow.

 

[ElectroNautical]

How do you adjust the air fuel ratio on a diesel smarty pants?

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.

 

[Blackmagic94]

Why would I do that? I love it here. It's a 'Target Rich Environment' and as much fun as shooting fish in a barrel...

You sir are a bot

 

[Bigbore500r]

And lastly...duty cycle is proportional to RPMs. A boat up on plane is often running at 3,500 RPM for hours at a time. When was the last time you saw any auto or truck engine run at a continuous 3,500 RPM for more than a minute or two? Even climbing the steepest, longest hill you can think of towing at maximum rated capacity, you'll never see 3,500 RPM for HOURS at a time.

Statements like this are what make me wonder what failed tech startup programmed your AI logic.

Heres just a few examples

 

[Bigbore500r]

Funny thing, since you're such a BMOC here I'd have thought you'd have some kind of presence on performanceboats.com. You don't have a great reputation there, maybe that's why you hang out here. Here's your chance to shine. Post a reply to this post and see how fast you get your ass laughed off the site. 40,000 plus members there and I'm sure you'll have a great time...

Mercruiser 496 MPI tuning for engine mods

www.performanceboats.com

Brah . . .

 

[ElectroNautical]

You sir are a bot

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).