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

i wanna try it
thanks

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

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

Also, RS4 injectors are useless for you.

Because they will not fit your car physically.

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.

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.

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.