Understanding duty cycle - question

[ottafish]

Hi All,
I apologise if this is a silly question.. I've searched for the last few days trying to get an understanding but haven't the answer yet.

I've been reading and researching about nos on a Gen2 via EcuEditor and the common thread is to lock the injectors at a 50/50 duty cycle.

I'm just wondering if someone can explain what exactly it means to lock the injectors into a 50/50 cycle.
Does it refer to the "Nitrous Duty" cycle towards the bottom of the nos page in the EcuEditor?
Or am I way off base as we're talking about fuel injector cycle?

And does it mean that across the gears of 2-5 then all would be set to a 50 nos duty cycle?

Any pointers would be appreciated - thanks.. I'm reading and learning as much as I can..
Thanks

 

[RedBull]

It is not fast enough ~ for you already ? •

 

[ottafish]

It is not fast enough ~ for you already ? •

Heaps fast enough. But have an inquisitive mind. Have been reading about the ecueditor, then the wollrich software.
Then the timing removal as opposed to a tre, then the quickshifter option via EE and onto nos.

Since owning the bike, I've been gradually reading the forum back over time and learning as much as I can. I'm the sort of person that takes user manuals to bed and reads front to back.

It's something that I haven't found info on. I've had nos on my race cars but it was always wet and carbie, not injected.

So thought I did ask and learn more.

 

[Mr Brown]

Wet systems and carb setups use an independent supply of fuel to compensate for the added oxygen, dry setups for fuel injection rely on tuning the existing injectors to add what's needed.
As I understand it, injector cycle is the amount of time an given injector is open, i.e. delivering fuel. Think of it like this: your motor needs extra fuel when you are using a power adder, because you are supplying more air. you can use your existing injectors to add more fuel by telling them to stay open longer during each pulse. If you keep adding air (higher boost pressures or bigger nitrous jets) at a certain point your existing injectors will not be able to keep up. Anything over 50% duty cycle means that a given injector is "on" (open) more than it is "off" (closed). As an injector approaches 100% duty cycle there is a danger of failure, it will likely lock, either open constantly delivering fuel, or closed delivering none. Either way you have problems. If your power adder requires more fuel than your existing injectors can supply at a safe duty cycle, you need bigger ones.
Hope this makes sense.....

 

[busakiller]

So on gen 2 bikes they have 8 injectors. 50/50 means that your injectors are equal now. Factory they aren't equal all the time I believe. It's like 70/30, 60/40. Lower injectors spray the most and upper's sprayING the less. When you do 50/50 your having the injectors spraying the same amount at the same time. That will help you get the most fuel out of your fuel system. On my k8 gsxr I had my injectors at 50/50 when the nitrous would come on at a set rpm. Helped get the most out the fuel system.

 

[Mr Brown]

Balance percentage and duty cycle percentage are two separate things. Just to be clear, I was referring to injector duty cycle, Busakiller is referring to balance between the two sets of injectors

 

[ottafish]

@Mr Brown and Busakiller - thank you very much for taking the time to respond, appreciated.

Now I'm starting to understand. I didn't realise there is two different systems as such.
The injectors themselves can have a duty cycle, of say 40/60 - 40% open during any given injector pulse.

Then there is the other side of balancing the upper and lower injectors to 50/50, (lock the injectors 50/50) on either a switchable map A or B and then adding the necessary fuel to compensate for the added "boost" which will be controlled by the injector duty cycle as per above. Because I'm assuming you wouldn't lock the injectors to a 50/50 for normal, everyday riding.

This is also taking into account timing and STP openings, which for this discussion assume has been adjusted to match.

Again, may thanks for taking the time to reply.

 

[Mr Brown]

@Mr Brown and Busakiller - thank you very much for taking the time to respond, appreciated.

Now I'm starting to understand. I didn't realise there is two different systems as such.
The injectors themselves can have a duty cycle, of say 40/60 - 40% open during any given injector pulse.
Correct, but this would be expressed as simply 40% duty cycle. The remaining is implied.

Then there is the other side of balancing the upper and lower injectors to 50/50, (lock the injectors 50/50) on either a switchable map A or B and then adding the necessary fuel to compensate for the added "boost" which will be controlled by the injector duty cycle as per above. Because I'm assuming you wouldn't lock the injectors to a 50/50 for normal, everyday riding.
Injector balance applies only to bikes (or other platforms) with more than one set of injectors that are able to be controlled independently. The advantages for performance are obvious, but as far as street riding someone with more knowledge than I will need to chime in. I have a Gen one, so I'm unfamiliar with what works best.

This is also taking into account timing and STP openings, which for this discussion assume has been adjusted to match.
Correct.

Again, may thanks for taking the time to reply.