NefMoto

Hi
i'm planned to tune my stage 2++ with antilag for e85 fuel
where i can see or know the percentage of duty cycle of the standard injectors
 i need to raise 25% the primary fuel channel so i want to know if the injectors are capable to support it without lean problem.
 i will share my result.
thanks

use me7logger and log injector open time, rpm. logger will do the rest.

i wanna try it
thanks

its 95% on wot acceleration
Can i go at 110% 115% duty cycle or i will not work?

100% duty cycle means injectors are open 100% of the time.
Unless you invent a time machine, going higher than 100% will not work.

i have some peak at 105%
i wanna try to find rs4 injectors

Yes, you might request 105%, but that is physically impossible.
So that means you are running lean.

Also, RS4 injectors are useless for you.

why rs4 injectors are useless
that strange for a stage2++ basicly designed for stock injectors.
i thinks i wanna go for evc14 550cc for my e85 tune

Because they will not fit your car physically.

there are adapter on ebay

Does it really or does it mean that they are open 100% of the time the inlet valve is open, or 100% of the intake stroke...?
You can (if you wish) squirt fuel on closed intake valves (although this is non-standard for ME7 if I remember things correctly) which in reality has been very common in the past.
For reference, just study batch, bank and sequential injection.

100% dutycycle being equivalent of having the injectors open "all of the time" as you say is a bit misleading as they are not open all through intake, compression, combustion and exhaust phase so "all of the time" might be a wrong choice of wording.

I'm pretty sure fuel squirts on closed intake valves; but I'll add my disclaimer, not a pro yada, yada, yada.... I thought the idea here was to cool intake valves/atomize fuel? Pardon my lack of knowledge, but why would you not want to do this?

To the OP; go with the ecv14 and then no worries about the lack of fuel;) - sorry to ask questions in your thread.

Very common as rpm's increase because lack of "valve open time" becomes evident. I'm just not sure that ME7 is configured stock to do so for all four strokes, that's all I'm saying but the timing of the injector is very important here (latency vs battery voltage etc.) to be able to properly time this once the revs go up.
Generally though, AFR is not that affected by squiritng fuel on closed valves.


You can indeed squirt fuel on closed intake valves, and the fuel will basically just stay in the port until the valve opens again. During this time, the fuel might have the time to be heated up and vaporize and this might in theory improve efficiency.
Also, squiritng fuel on closed valves will in time accumulate carbon residue on the valves.
By using sequential fueling (instead of batch/bank) you will most likely improve low engine speed emissions and low speed mileage as squirting fuel into a cylinder that is already closed won't be beneficial for the engine efficiency.

fredrik_a, you seem very confused about things. Sequential, batch and bank injection has absolutely nothing to do with duty cycle.

Injector duty cycle means the percentage of time that an injector is supplied with power.
Because we have a four stroke engine, it takes two revolutions to complete one cycle.

So for example at 7000rpm it takes 8.57ms to complete one revolution (1/7000*60*1000).
For two revolutions it takes 17.14ms.

So at 7000 rpm, 17.14ms injector on time is 100% duty cycle. This on time contains latency compensation as well.

Of course fuel is sprayed when the valve is closed! This is how all port injected engines work.
Injection angle is only important at very low loads.
There is nothing misleading about what I have said.
Of course 100% is equal to the injectors being open all the time, as they ARE open through all of the four phases. We are talking about duty cycle here.
100% pretty much means there is constant power to them.

This is where we clearly use different definitions, perhaps because VCDS/VAG-Com use another definition compared to what I'm used to.
You say "So at 7000 rpm, 17.14ms injector on time is 100% duty cycle" which is absolutely correct, but these 17.14 ms injector time is what is available per stroke, not necessarily meaning that you automativcally want to spray in all strokes?
Why would you want to continue to spray another 17.14 ms in the compression stroke, and then another 17.14 ms in the combustion stroke and then finally another 17.14 ms in the exhaust stroke?

Furthermore, if you adjust the trigger/starting point of the injection to slightly before TDC between the exhaust stroke and intake stroke, you can have more injector time than 17.14 ms, and this will provide higher duty cycles than 100%, at least i my experience.

Here is a defenition I'm more familiar with. http://www.igotasti.com/vBforum/showthread.php?661-Injector-Duty-Cycle-explained

To put it as simply as I can, IDC is how much of the intake stroke the injector is firing and is represented in % of intake stroke. The IPW is how long the injector is actually open and is represented in milliseconds. So if your intake stroke lasts for 20ms and your IPW is 22ms, then your resulting IDC will be 110%

Using your logic, the injector would be on all the time, also during the second stroke (first + second stroke equals one crank shaft revolution) with a total of 34.28 ms...
This way (when you say that the injectors are on all the time through all strokes) would mean (to me) that we have an injector duty cycle of 34.28/17.14 = 200% which is why I'm a bit hesitant in beleiving that ME7 actually squirts fuel during all phases.

This is also why IDC's actually can be over 100% if you want to.


If we continue with your logic, would 80% dc @ 7000 rpms mean that the injectors would fire for 13.8 ms, then pause for 3.3 ms, wait for the compression stroke and then fire for another 13.8 ms, pause for 3.3 ms until the compression stroke begins, then fire again for 13.8 ms and so on through all strokes or is "fireing through all strokes as you say" just valid for dutycycles of a 100%?
If we had a dutycycle of 20%, what would be the benefit in squirting some fuel in other strokes than intake or are you saying that ME7 basically doesn't care which stroke it is in when it comes to fueling as long as the timing is correct regarding TDC and BDC, it just fires away regardless...? I find this hard to beleive although I might be mistaken of course.

First, I hope you are not trolling me. I'll assume you're not, and perhaps this is useful for someone, but I think you should really read a book about how a port injected engine works, as this is really the basics.

No, 17.14 ms injector time is the total time available, as that is how long it takes a four stroke engine to complete a cycle at 7000 RPM.

Let's break it down for you.
7000 rpm means it takes 1/7000 minutes per revolution. Which is 60/7000 seconds per revolution. Which is 60000/7000 or 8.57 milliseconds per revolution.
A four stroke engine needs two revolutions to complete a cycle. The cycle consists of the four strokes.
This means the total time available is 8.57*2 or 17.14ms to spray fuel during every cycle.

What you wrote here is completely wrong, and that is not how a four stroke engine works. Read above for the calculation.

Unless you invent a time machine, there is no way the injectors can be on for more than 17.14ms at 7000 rpm in a four stroke engine, as that is how much time is available per cycle before the next cycle begins. See the explanation above.

The indicated duty cycle can be over 100% in two cases.
First case is a rounding error in the calculations.
Second case is if requested injector pulsewidth is used for the calculation without taking in account latency compensation. Then it is only requested pulsewidth, actual duty cycle can never extend 100%, as 100% means the device is on all the time. Short to ground if you will.


This is completely wrong. Duty cycle is the percentage of the total time a device spends in the "ON" position. Whoever wrote that IDC is represented as a percentage of the intake stroke has no idea what he is on about :)

The rest of the things you wrote also make no sense at all. Please read what I say. If how I explain it is not good enough for you, please read a book on four stroke engines.
A. Graham Bell has a pretty good book.