? about injecter opening time

[TURBOZ]

On my FAST i have had the injecter opening time set at 1.0m/s. I changed it to 1.7m/s when I went from 83# injecters to 160# injecters. This helped the numbers in the VE table. My question is are there limits with this number? Can it be set to high or too low as long as you can still work with in your VE table

 

[TurboTR]

That will probably make it idle way too rich with the 160's.

TurboTR

 

[Joe Lubrant]

That will probably make it idle way too rich with the 160's.

TurboTR

I Agree.......normally .8 to 1.0 has been my set point for 160's.

1.7 is way to high...remembering that the min. inj opening time is always added to the ecu's calculation for the input injector size.

Joe

 

[bruce]

Let's see, F.A.S.T. claimed a true VE table, and ideal gas law as a selling point, and then you have to guess, or approximate the injector openings. It sounds like in the end, weither it's a true of VE table is actually moot, since there's so much guessing or fudging of numbers to get the system to work (VE tables to line up with reasonable values).

Can someone shine some light on why if you have to guess/ fudge the entries, why it's better then a well designed BPC, or BPW calculation style of calculation?.

 

[Joe Lubrant]

Let's see, F.A.S.T. claimed a true VE table, and ideal gas law as a selling point, and then you have to guess, or approximate the injector openings. It sounds like in the end, weither it's a true of VE table is actually moot, since there's so much guessing or fudging of numbers to get the system to work (VE tables to line up with reasonable values).

Can someone shine some light on why if you have to guess/ fudge the entries, why it's better then a well designed BPC, or BPW calculation style of calculation?.

First of all BRUCE wouldn't it be NICE for all the INJECTOR MFG'S to SPECIFY what their Minimum Injector Opening Times were??? Even if they did it would be subject to slight change due to conditions.

Lets see 160#, 95#, 83#, 75#, 72#, 65#, 60#, 57#, 55#, 50#, 42.5#, 40#, 38#, 36#, 32#, 30#, 28#, 19#, 17# Injectors. These seem to cover most used. Then there are the differences relating to high impedance and low impedance etc, Not to mention the constantly varying volatge changes & loads the injectors are operated under.

For your information, I am listing below what is printed in the FAST Help/Manual regarding Minimum Injector Opening Time:

6.2.6 Injector Opening Time (ms)
You should not have to change this parameter with most popular engine applications. Always start at 1.0 ms.
This parameter defines the amount of time that it takes from the instant that an electrical signal is applied to a fuel injector until fuel actually flows from the injector.
This value is added to the base pulsewidth value to compensate for injector opening delays. Because the base pulsewidth value is always changing and this value is constant, the effects of changing this setting will be most pronounced where the base pulsewidths are smallest - typically at idle and light cruise. Here is an example.
Let's assume the engine is idling, and the base pulsewidth value is 3.0 milliseconds. The injector opening time is set to 1.0 millisecond. These two values will be added together, and the reported pulsewidth will be 4.0 milliseconds. If you were to increase the injector opening time by 0.5 milliseconds, the new reported pulsewidth would be 4.5 milliseconds - a 12.5% increase.
Now let's assume that with this same calibration, the base pulsewidth at full throttle and 5000 RPM is 20.0 milliseconds. With an injector opening time of 1.0 millisecond, the reported pulsewidth would be 21.0 milliseconds. Increasing the injector opening time by 0.5 millisecond as in the last example yields a new reported pulsewidth of 21.5 milliseconds - a mere 2.5% increase!
The actual time an injector takes to open will vary slightly as battery voltage fluctuates. Higher battery voltages will open an injector faster, so the injector opening time will be reduced to compensate for this. Alternatively, as battery voltage decreases, an injector will be slower to open. The injector opening time is increased to make up for this. Note that this battery correction only applies to the “Injector Opening Time” – the extra time that is added to the base pulse width value to compensate for injector opening delays. The base injector pulse width calculated by the ECU is not changed. The opening time will be modified as per the following graph:

"UNABLE TO POST GRAPH"

To my & all others knowledge, all ecu manufacturers, including OEM, have to deal with the same issues as it relates to varying conditions etc., and appropriate corrections are applied to compensate.

Joe

 

[norbs]

That is a great explanation, this is one of those grey areas that everyone is just not sure about. Good information, for this site.

 

[TurboTR]

bruce I don't know what your problem with FAST is. However, it seems to really be an issue with JL. I suspect because you think there was some implied lack of knowledge on your part from one of his replies re: impressive et's or lack thereof. Whatever it is, your drooling, rabid dog attacks are just looking more and more juvenile and ridiculous. What engine VE and the ideal gas law has to do with injector response time, and/or how FAST is supposed to spec injector response times for all injectors in the world is beyond me. Perhaps you can reach into your vast internet knowledge pool and produce these numbers for us, if it concerns you so much. On second thought, forget it.

In my experience the FAST system has worked ~ fantastically on every app, esp given the price point. Personally I have several years experience programming full authority engine control in C language on multi-pc, realtime OS, $50,000 rapid prototyping engine controllers for the US DOE and EPA on emissions research, etc projects. I feel that I speak with more than just hobbyist experience when I say that IME the FAST system works very well on a high performance application and calibrates relatively easily compared to its peers, again all things considered. None of this petty attack cr*p has been warranted that I have seen.

Again I feel compelled to say- get over it already. Why this cr*p has not been banned long ago is a mystery. If it were my decision it would have ceased long ago. Frankly I am beyond tired of feeling needlessly offended and feeling the need to waste valuable time trying to counter some of this petty personal agenda crap re: the FAST system. Again I say we don't need it here on this board.

TurboTR

 

[bruce]

bruce I don't know what your problem with FAST is.

Because there isn't one.
There are some people thou, that like asking questions, for some of us, that's the way we learn things. For some it's also about being an informed customer. Maybe you like not knowing the nuts and bolts of the ecm, but that's no excuse for you to hijack a thread, with opinion when facts are asked for.

Now that we're past that, can you contribute some thing related to the question posed?.

 

[bruce]

First of all BRUCE wouldn't it be NICE for all the INJECTOR MFG'S to SPECIFY what their Minimum Injector Opening Times were??? Even if they did it would be subject to slight change due to conditions.

Lets see 160#, 95#, 83#, 75#, 72#, 65#, 60#, 57#, 55#, 50#, 42.5#, 40#, 38#, 36#, 32#, 30#, 28#, 19#, 17# Injectors. These seem to cover most used. Then there are the differences relating to high impedance and low impedance etc, Not to mention the constantly varying volatge changes & loads the injectors are operated under.

For your information, I am listing below what is printed in the FAST Help/Manual regarding Minimum Injector Opening Time:

6.2.6 Injector Opening Time (ms)
You should not have to change this parameter with most popular engine applications. Always start at 1.0 ms.
This parameter defines the amount of time that it takes from the instant that an electrical signal is applied to a fuel injector until fuel actually flows from the injector.
This value is added to the base pulsewidth value to compensate for injector opening delays. Because the base pulsewidth value is always changing and this value is constant, the effects of changing this setting will be most pronounced where the base pulsewidths are smallest - typically at idle and light cruise. Here is an example.
Let's assume the engine is idling, and the base pulsewidth value is 3.0 milliseconds. The injector opening time is set to 1.0 millisecond. These two values will be added together, and the reported pulsewidth will be 4.0 milliseconds. If you were to increase the injector opening time by 0.5 milliseconds, the new reported pulsewidth would be 4.5 milliseconds - a 12.5% increase.
Now let's assume that with this same calibration, the base pulsewidth at full throttle and 5000 RPM is 20.0 milliseconds. With an injector opening time of 1.0 millisecond, the reported pulsewidth would be 21.0 milliseconds. Increasing the injector opening time by 0.5 millisecond as in the last example yields a new reported pulsewidth of 21.5 milliseconds - a mere 2.5% increase!
The actual time an injector takes to open will vary slightly as battery voltage fluctuates. Higher battery voltages will open an injector faster, so the injector opening time will be reduced to compensate for this. Alternatively, as battery voltage decreases, an injector will be slower to open. The injector opening time is increased to make up for this. Note that this battery correction only applies to the “Injector Opening Time” – the extra time that is added to the base pulse width value to compensate for injector opening delays. The base injector pulse width calculated by the ECU is not changed. The opening time will be modified as per the following graph:

"UNABLE TO POST GRAPH"

To my & all others knowledge, all ecu manufacturers, including OEM, have to deal with the same issues as it relates to varying conditions etc., and appropriate corrections are applied to compensate.

Joe

Nice cut and paste, but it completely ignores answering the guestion.

*****
Original posting:
Let's see, F.A.S.T. claimed a true VE table, and ideal gas law as a selling point, and then you have to guess, or approximate the injector openings. It sounds like in the end, weither it's a true of VE table is actually moot, since there's so much guessing or fudging of numbers to get the system to work (VE tables to line up with reasonable values).
The Question:
Can someone shine some light on why if you have to guess/ fudge the entries, why it's better then a well designed BPC, or BPW calculation style of calculation?.
*****


BTW, since there are just 19 popular injectors, and with all the time the various *Injector Blue Printers* have invested in cleaning and testing injectors, it seems odd, that none of the injector manufacturers or aftermarket ecm cos., have bothered to offer this material.

 

[Joe Lubrant]

Nice cut and paste, but it completely ignores answering the guestion.

*****
Original posting:
Let's see, F.A.S.T. claimed a true VE table, and ideal gas law as a selling point, and then you have to guess, or approximate the injector openings. It sounds like in the end, weither it's a true of VE table is actually moot, since there's so much guessing or fudging of numbers to get the system to work (VE tables to line up with reasonable values).
The Question:
Can someone shine some light on why if you have to guess/ fudge the entries, why it's better then a well designed BPC, or BPW calculation style of calculation?.
*****


BTW, since there are just 19 popular injectors, and with all the time the various *Injector Blue Printers* have invested in cleaning and testing injectors, it seems odd, that none of the injector manufacturers or aftermarket ecm cos., have bothered to offer this material.

BRUCE!

It was a NICE cut and paste!!...but I also made statements, prior to and after for additional clarification/information. I posted it for "Average People", to give them a better understanding relating to the Injector Opening Entry requirement in the software/setup.

I'm sure you of all people understand "VARIABLES", you can do YOUR calculations, Vertical, Horizontal, Sideways, or Upside Down, but if there is a Variable......Nothing will be ABSOLUTE!!! Appropriate correction factors need to be applied to keep everything within an ACCEPTABLE TOLERANCE!!

You seem to live in your own world of PERFECTION....and apparently think Tolerances do not exist.

"Please post by "Starting a New Thread"....To inform us how any ecu, "Especially Yours" is More Precise then any other in the World!

It is Evident to Everyone that "You do have a problem" with any posts relating to Fast!!!

You also state that there is so much guessing on entries....NOT SO!
Your insinuations of Mutiple guessing is absolutely UNTRUE/FALSE!!!
How does one (1) entry of minimum injector opening time constitute a plural mutiple quessing insinuation???

BTW as far as the Injector Mfg giving the information, some have, but as I stated in earlier post, it will vary based on conditions. I have personally seen it vary slightly from injector to injector of the same mfg, size, and voltage applied.

So again, nothing is ABSOLUTE!!


In Closing, I agree the thread has gone completely off topic from the original question by TURBOZ.
His question was answered adequately and this thread will be CLOSED.

Joe