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-   -   Injector Balance - General Injector Setup (https://www.nopistons.com/performance-mods-20/injector-balance-general-injector-setup-33192/)

Jims5543 02-04-2004 10:41 AM

Some questions.



What split are you guys running for your injector balance.



Tell me if I understand this correctly.



My split tells the ecu which injector to use or how much of the injector to use to deliver the fuel.



So if I have a 50/50 both injectors will spray 50/50 to deliver the needed fuel.



So lets say I have a fuel setting of 40 at 4000 RPM my balance screen says to use 50% primary. So I would be getting equal amounts of fuel from Primary and secondary injectors.



Worded differently:

So if my primary is a 500cc (theoretical) and it maxes out the 1300cc secondary will only deliver 500cc????



I am wondering if my injector balance is what is causing my car to become fuel starved?



On my ECU @ 4000 RPM 70% of the fuel is being supplied by my primaries.



I feel like the optimum setting would be a 50/50 setup. But then again wouldn't I want more of the work to be dome by my secondaries up in the higher RPMs at higher boost? My setup I have now never lets the secondaries do more than 50% of the work. I am not sure if that is good.

j9fd3s 02-04-2004 10:57 AM

what the factory does on the fc is run 100% off the primaries until 3800 and then they switch* to 50/50. on the fd it switches at 1psi or 3200rpms whichever comes first.



since you have that nifty blend thing you could make it turn on a lot more gradually than the factory does (they are always hardware limited), the idea being you want a seamless transition



* theres a couple of different ways ecu's can do this, i'll post pics at work

TYSON 02-04-2004 11:30 AM


Originally Posted by Jims5543' date='Feb 4 2004, 11:41 AM
Some questions.



Worded differently:

So if my primary is a 500cc (theoretical) and it maxes out the 1300cc secondary will only deliver 500cc????

No. Your ECU really has no idea what size your injectors are. (Power FC excepted)



It is only based on time. Your ECU opens the injector for a certain amount of time, and the injector volume determines how much fuel can come out in that time.



There's a couple ways MY ECU does the staging.



You can run the primaries anywhere up to, let's say, 85%, then the secondaries come on. The primaries STAY at 85%, while the secondaries come on at about 5% and work their way up.





Or you can run the primaries up to 85% then the secondaries come on. The primaries drop down to the same duty cycle as the secondaries and they work up together. You have to figure out where to start the secondaries and primaries together so that the transition is smooth.



IE: If you have 4 identical injectors, you could take the primaries up to 80%, then stage the primaries and secondaries in together at a little more than 40%. If they aren't identical, you have to calculate total volume versus primary volume and figure out a new percentage.



This is with Haltech E11. I see you have a Moo-tec, but I doubt they're that different if you think about it.



How much total injector volume do you have? Your garage profile says you have 550 / 1300. You could likely just not have enough injector size.

Jims5543 02-04-2004 03:24 PM

My Motec asks for a ratio between primary and secondary on intial setup. I have a ratio of 2.20 (should be 2.36) between them. So now I am confused as to what to tell the ECU to do. Initially I thought I needed to tell it to use the secondaries more but now it seems like it is since it knows the secondaries are bigger already. Bah!!



I am going to play w/ this a little. I have enough fuel to support 500RWHP. I should have better a/f ratios than I am getting and I think this might be part of the problem.



When I looked at my injector balance screen the map I am using has the primaries doing all the work. The secondaries are coming in at really hight boost and really high RPMs.



I did find out that my injector pulse width was set too wide.

j9fd3s 02-05-2004 10:56 AM

it sounds like you're on to something


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