Injector Latency (dead time)

[RANeff]

Before I go test our injectors themselfs, I thought Id search and ask:

Does anyone know the fuel injector latency for the Yamaha R6, or for any of the 600cc japanese engines? Any model year will do for now

[RANeff]

Before I go test our injectors themselfs, I thought Id search and ask:

Does anyone know the fuel injector latency for the Yamaha R6, or for any of the 600cc japanese engines? Any model year will do for now

[Drew Price]

You may want to consult the programming threads on the MegaSquirt forums (MSEFI) - the initial setup stickies and how-to docs have lots of good explanation and baselines for different styles.

That's where our team learned a lot of our early info on setting up the standalone.

I don't remember what ours was off hand (Suzuki 450 though) and I don't want to embarass myself with a guess, it was something like 0.5ms-1.0ms?

But what do I know, I'm a suspension guy,

Best,
Drew

[Grant Mahler]

1.5ms is a very safe time to assume it takes to get to fully developed flow. 1.5 is what is quoted in the MS manual.

1.0-1.1 is what most of the injectors I saw tested took.

Depends primarily on injector design, then on fuel pressure.

[Drew Price]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Grant Mahler:
Depends primarily on injector design, then on fuel pressure. </div></BLOCKQUOTE>

You just made me want to mod the solenoids in the fuel injectors to Mongo status. Super strong, super fast.

Q: "You've got a lot of lifter lash in there, eh?"

A: "Nope. That's the fuel injectors."

**clackclackclack POP clackclackclackclackclack POP clackclack.....***


Best,
Drew

[Poe]

Battery voltage plays a pretty big part of injector dead time too. Whether this is built into the dead time setting as a table or if a basic dead time setting is compensated with another table based on voltage, the effect of the voltage supplied to the injectors needs to be accounted for.

[RANeff]

Cool cool, I didn't expect anyone to have that off the top of their heads. I just want to do it right, although MS says to just use 1.0ms.

Ill just have to test them on an oscilloscope, probably at 13.2v, 12v, and 11.2v, then average the latency's recorded.

I believe in Msextra there is a voltage correction factor, which I should be able to get from the std deviation from testing.

thanks guys

Ryan

[Grant Mahler]

Yea the numbers I posted were @ 12v. At 14.4 they will be faster.

[jalai]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by RanE5-CSU:
Cool cool, I didn't expect anyone to have that off the top of their heads. I just want to do it right, although MS says to just use 1.0ms.

Ill just have to test them on an oscilloscope, probably at 13.2v, 12v, and 11.2v, then average the latency's recorded.

I believe in Msextra there is a voltage correction factor, which I should be able to get from the std deviation from testing.

thanks guys

Ryan </div></BLOCKQUOTE>

You can't measure DeadTime with oscilloscope.
Deadtime can calculate from "linear" part of flow curve (extend linear part of curve to zero flow)....
Example here...(same injector, voltage and pressure, but different injector driver)
http://picasaweb.google.com/ja...#5408341941912630674 (http://picasaweb.google.com/jaritlaine/Injectors#5408341941912630674)

[RANeff]

You actually can, with a very low ohm resistor, a simple breadboard setup and an oscilloscope.

[jalai]

Measuring injector current is possible to get "opening time" (time from pulse start -&gt; injector fully open).
But, this is not the same as Deadtime.

Some explanations here...
http://www.injectordynamics.co...haracterization.html (http://www.injectordynamics.com/dynamic-characterization.html)

[RANeff]

Why, yes it is.

A quote directly from your article:

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> Dead Time, Latency, Offset, Battery Compensation. These are all different terms to describe the same thing.....


As I said, these terms all describe the same thing. That is the injectors inability to respond instantly to the signals coming from the ECU.

When the injector receives the signal from the ECU a few interesting things happen. First, the coil must build a magnetic field strong enough to move the valve. Second, the valve must move anywhere from 10 to 30 thousandths of an inch to reach the fully open position, at which point its flow rate equals that of the static flow rating.

</div></BLOCKQUOTE>

Exactly what do you see in your source that implies dead time is not the same as latency, opening time, etc?

[jalai]

Dead time is the same as "Latency, Offset, Battery Compensation", BUT it is not same as "opening time".
Where You see there that "opening time" is the same as "Deadtime"?

Read one more time what Injector Dynamics wrote.

[RANeff]

I dont believe you realize the connection.


Latency, etc is the amount of time it takes the injector to open once the ECU tells it to. Please, explain to me why you think my methods will not produce correct results?

[jalai]

One more time.... read this part from ID Deadtime exlanation.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> When the injector receives the signal from the ECU a few interesting things happen. First, the coil must build a magnetic field strong enough to move the valve. Second, the valve must move anywhere from 10 to 30 thousandths of an inch to reach the fully open position, at which point its flow rate equals that of the static flow rating.

The time wasted charging the coil, and coaxing the slow moving valve to its fully open position reduces the flow, and has the same effect as shortening the pulsewidth. The end result is that a 1000cc injector does not flow 500 cc's per minute at 50% duty cycle as you would expect.

But that's only half the story. The same delays exist when we remove the signal from the injector. First, the coil needs to discharge to the point that the magnetic field collapses and "lets go" of the valve. Second, the valve has to move from the fully open to the closed position. These delays cause the injector to continue to flow after the signal has been removed, and has the same effect as lengthening the pulsewidth.
When we combine the opening and closing delays, and consider their total effect on dynamic flow, we have the dead time .

It is worth noting at this point that dead time is not something you can determine with an oscilloscope. You must measure the dynamic flow where all delays are combined to determine the dead time accurately. </div></BLOCKQUOTE>

Can You tell, how You measure DT with oscilloscope?

[RANeff]

I figured this is what you meant. It would be foolish to think injectors close instantly. However, I am not too concerned with it.


You can measure this as well, I wish I could show you a printout of our tests but our scopes are too old. the magnetic field generated by the coil closing also shows up as a bump in the voltage curve.


When you consider the fuel pressure you run, your injectors will close much much faster than they will open. It is quite miniscule.

I only needed open time, as our Engine management only corrects for it and voltage compensation, not close-time.

[Grant Mahler]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by jalai:
Can You tell, how You measure DT with oscilloscope? </div></BLOCKQUOTE>

I am baffled as to why you are so concerned about something like this? Pick an opening time - who cares, and tune the engine. If you were running up against the lower limits of the injectors opening time at idle, or the injectors were running 90+% duty cycle, then I could see where you are coming from. But you appear to be spending a massive amount of energy on something that shouldn't matter at all.

My opinion? Move on.

[RANeff]

Exactly. we did a simple test to get a good starting point for the closest tune we could do. Im not sure why my test isnt an acceptable way of doing it.

[jalai]

Topic is "Injector Latency (dead time)".
And RanE5-CSU wrote "I just want to do it right".

So.....

- You can't measure Deadtime with a oscilloscope
- You can measure injector opening time and closing time with oscilloscope (closing can be measure example with knock sensor, not voltage)
- BUT You don't need that values anything..... You need Deadtime, although Megamanual says Inj_open_time. IT IS WRONG.
- And Deadtime can be determine from flow values.

And closing time is much more impressive that megamanual says. Try to measure it.

One example from My papernotes....
SiemensDeka injector #52 (550cc) 2,5ohm.

Flyback 60V pulse 1,3ms inj_tot_open 1,1ms -&gt; closed 2,2ms (-&gt; closing time 0,9ms)
Flyback 250V pulse 1,3ms inj_tot_open 1,1ms -&gt; closed 2,1ms (-&gt; closing time 0,8ms)

And this injector Deadtime is something about 0,6-0,7ms.

If You don't understant this, I give up.


And I don't know why I spend My energy to try to tell You this?

[DanGrey]

I was planning to post another thread but I guess this thread will just be perfect for my question.. okay, I would just like to ask if oil companies came up with blend additives that prevents the carbon deposit? It always takes away a lot of my time cleaning for fuel injectors.. This just a thought. Thanks

[RANeff]

I would say this is not the thread to post that question in...

[DanGrey]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by RanE5-CSU:
I would say this is not the thread to post that question in... </div></BLOCKQUOTE>

Really?hmm.. i tried the search tab and it this appeared when i searched for the injector.. anyway, any ideas?

[Adambomb]

Typing in a keyword in the search tab and blindly clicking on the first link that comes up isn't really "using" the search tab. More like mis-using it. Oil additives have nothing to do with injector latency.

[DanGrey]

i dont think that it doesnt have to do at all with oil additives. Maybe DanGrey is referring to the fuel?. (http://www.123.com)